Patent Application
20230144810
The field of the invention relates generally to the field of medicine, medical devices, immunology and cancer, specifically methods and devices useful for generating immune responses in subjects.
It is to be understood that both the foregoing general description of the embodiments and the following detailed description are exemplary, and thus do not restrict the scope of the embodiments.
In one aspect, the invention provides a method for generating an immune response in a subject, comprising administering to the subject’s skin an immunizing composition, wherein the composition comprises one or more cancer antigens and is administered with a microneedle delivery device.
In some embodiments, the immunizing composition comprises an immunologically-effective amount of one or more polypeptides or antigenic fragments or variants thereof. In some embodiments, the immunizing composition comprises an immunologically-effective amount of one or more nucleic acids encoding one or more polypeptides or antigenic fragments or variants thereof. In some embodiments, the one or more nucleic acids are provided by one or more viral vectors. In some embodiments, the cancer antigen is provided as a modified tumor cell. In some embodiments, the cancer antigen is provided as an antigen presenting cell loaded with the cancer antigen. In some embodiments, the cancer antigen is provided as a polypeptide.
In some embodiments, the immunizing composition is administered in combination with one or more additional cancer therapies, including, for example, radiation, chemotherapy, surgery, or immunotherapy or any of the cancer therapies as specified herein.
In some embodiments, the administering comprises a repeated motion of penetrating the microneedle delivery device into the subject’s skin.
In some embodiments, the administering comprises a repeated motion of penetrating the microneedle delivery device into the subject’s skin in different areas of the subject’s body.
In some embodiments, the subject’s skin in the head, limbs and/or torso regions are repeatedly penetrated by the microneedle delivery device.
In some embodiments, the subject’s skin is penetrated in regions that are in proximity to one or more lymph nodes.
In some embodiments, the microneedle delivery device comprises
In some embodiments, the microneedles are non-hollow.
In some embodiments, the means to encourage flow of the composition contained in the reservoir into the skin is selected from the group consisting of a plunger, pump and suction mechanism.
In some embodiments, the means to encourage flow of the composition contained in the reservoir into the skin is a mechanical spring loaded pump system.
In some embodiments, the microneedles have a single groove inset along the outer wall of the microneedle, wherein the single groove has a screw thread shape going clockwise or counterclockwise around the microneedle.
In some embodiments, the microneedles are from 0.1 mm to about 2.5 mm in length and from 0.01 mm to about 0.05 mm in diameter.
In some embodiments, the microneedles are made from a substance comprising gold.
In some embodiments, the plurality of microneedles comprises an array of microneedles in the shape of a circle.
In some embodiments, the microneedles are made of 24-carat gold plated stainless steel and comprise an array of 20 microneedles.
Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating specific embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
The skilled artisan will understand that the drawings, described below, are for illustration purposes only. The drawings are not intended to limit the scope of the present teachings in any way.
Reference will now be made in detail to the presently preferred embodiments of the invention which, together with the drawings and the following examples, serve to explain the principles of the invention. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is understood that other embodiments may be utilized, and that structural, biological, and chemical changes may be made without departing from the spirit and scope of the present invention. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art.
The practice of the present invention employs, unless otherwise indicated, conventional techniques of molecular biology (including recombinant techniques), microbiology, cell biology, biochemistry and immunology, which are within the skill of the art. Such techniques are explained fully in the literature. See, e.g., Sambrook et al. Molecular Cloning: A Laboratory Manual, 2nd edition (1989); Current Protocols in Molecular Biology (F. M. Ausubel et al. eds. (1987)); the series Methods in Enzymology (Academic Press, Inc.); PCR: A Practical Approach (M. MacPherson et al. IRL Press at Oxford University Press (1991)); PCR 2: A Practical Approach (M. J. MacPherson, B. D. Hames and G. R. Taylor eds. (1995)); Antibodies, A Laboratory Manual (Harlow and Lane eds. (1988)); Using Antibodies, A Laboratory Manual (Harlow and Lane eds. (1999)); and Animal Cell Culture (R. I. Freshney ed. (1987)).
Definitions of common terms in molecular biology may be found, for example, in Benjamin Lewin, Genes VII, published by Oxford University Press, 2000 (ISBN 019879276X); Kendrew et al. (eds.); The Encyclopedia of Molecular Biology, published by Blackwell Publishers, 1994 (ISBN 0632021829); and Robert A. Meyers (ed.), Molecular Biology and Biotechnology: a Comprehensive Desk Reference, published by Wiley, John & Sons, Inc., 1995 (ISBN 0471186341).
For the purpose of interpreting this specification, the following definitions will apply and whenever appropriate, terms used in the singular will also include the plural and vice versa. In the event that any definition set forth below conflicts with the usage of that word in any other document, including any document incorporated herein by reference, the definition set forth below shall always control for purposes of interpreting this specification and its associated claims unless a contrary meaning is clearly intended (for example in the document where the term is originally used). The use of “or” means “and/or” unless stated otherwise. As used in the specification and claims, the singular form “a,” “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “a cell” includes a plurality of cells, including mixtures thereof. The use of “comprise,” “comprises,” “comprising,” “include,” “includes,” and “including” are interchangeable and not intended to be limiting. Furthermore, where the description of one or more embodiments uses the term “comprising,” those skilled in the art would understand that, in some specific instances, the embodiment or embodiments can be alternatively described using the language “consisting essentially of” and/or “consisting of.”
As used herein, the term “about” means plus or minus 10% of the numerical value of the number with which it is being used.
In one embodiment, the invention provides a method for generating an immune response in a subject, comprising administering to the subject’s skin an immunizing composition, wherein the composition comprises one or more cancer antigens, wherein the composition is administered with a microneedle delivery device.
In another embodiment, the invention provides a method of treating cancer in a subject, comprising administering to the subject an effective amount of a composition comprising one or more cancer antigens, wherein the composition is administered with a microneedle delivery device.
The term “subject” as used herein is not limiting and is used interchangeably with patient. In some embodiments, the term subject refers to animals, such as mammals and the like. For example, mammals contemplated include humans, primates, dogs, cats, sheep, cattle, goats, pigs, horses, chickens, mice, rats, rabbits, guinea pigs, and the like. In some embodiments, the subject is a cancer patient or is a subject at risk for developing cancer.
The immunizing composition comprises one or more cancer antigens. In some embodiments, the immunizing composition comprises an immunologically-effective amount of one or more polypeptides derived from cancer cells or antigenic fragments or variants thereof.
In some embodiments, the immunizing composition comprises an immunologically-effective amount of one or more nucleic acids encoding one or more polypeptides or antigenic fragments or variants thereof. In some embodiments, the one or more nucleic acids are provided by one or more viral vectors. In some embodiments, the cancer antigen is provided as a modified tumor cell. In some embodiments, the cancer antigen is provided as an antigen presenting cell loaded with the cancer antigen. In some embodiments, the cancer antigen is provided as a polypeptide.
In some embodiments, the immunizing composition is administered in combination with one or more additional cancer therapies as provided herein, including, for example, radiation, chemotherapy, surgery, immunotherapy, immune checkpoint inhibitors, and the like.
In some embodiments, the cancer antigen as provided herein is from a cancer selected from the group consisting of breast cancer, chronic lymphocytic leukemia, colorectal cancer, esophageal cancer, gastric cancer, glioblastoma, liver cancer, melanoma, basal cell carcinoma, lung cancer (including small cell and non-small cell lung cancer), ovarian cancer, prostate cancer, pancreatic cancer, acute myeloid leukemia, renal cell carcinoma, head and neck squamous cell carcinoma, urinary bladder cancer, gallbladder adenocarcinoma and cholangiocarcinoma, uterine cancer, and non-Hodgkin lymphoma. Exemplary cancer antigens which can be useful in the present invention for these cancers are provided below.
Breast cancer is an immunogenic cancer entity and different types of infiltrating immune cells in primary tumors exhibit distinct prognostic and predictive significance. A large number of early phase immunotherapy trials have been conducted in breast cancer patients. Most of the completed vaccination studies targeted HER2 and carbohydrate antigens like MUC-1 and revealed rather disappointing results. Clinical data on the effects of immune checkpoint modulation with ipilimumab and other T cell-activating antibodies in breast cancer patients are emerging (Emens, 2012).
While CLL is not curable at present, many patients show only slow progression of the disease or worsening of symptoms. As patients do not benefit from an early onset of treatment, the initial approach is “watch and wait” (Richards et al., 1999). For patients with symptomatic or rapidly progressing disease, several treatment options are available. These include chemotherapy, targeted therapy, immune-based therapies like monoclonal antibodies, chimeric antigen-receptors (CARs) and active immunotherapy, and stem cell transplants.
Monoclonal antibodies are widely used in hematologic malignancies. This is due to the knowledge of suitable antigens based on the good characterization of immune cell surface molecules and the accessibility of tumor cells in blood or bone marrow. Common monoclonal antibodies used in CLL therapy target either CD20 or CD52. Rituximab, the first monoclonal anti-CD20 antibody originally approved by the FDA for treatment of NHLs, is now widely used in CLL therapy. Combinational treatment with rituximab/fludarabine/cyclophosphamide leads to higher CR rates and improved overall survival (OS) compared to the combination fludarabine/cyclophosphamide and has become the preferred treatment option (Hallek et al., 2008). Ofatumomab targets CD20 and is used for therapy of refractory CLL patients (Wierda et al., 2011). Obinutuzumab is another monoclonal anti-CD20 antibody used in first-line treatment in combination with chlorambucil (Goede et al., 2014).
Alemtuzumab is an anti-CD52 antibody used for treatment of patients with chemotherapy-resistant disease or patients with poor prognostic factors as del 17p or p53 mutations (Parikh et al., 2011). Novel monoclonal antibodies target CD37 (otlertuzumab, BI 836826, IMGN529 and (177)Lu-tetulomab) or CD40 (dacetuzumab and lucatumumab) and are tested in pre-clinical settings (Robak and Robak, 2014).
Several completed and ongoing trials are based on engineered autologous chimeric antigen receptor (CAR)-modified T cells with CD19 specificity (Maus et al., 2014). So far, only the minority of patients showed detectable or persistent CARs. One partial response (PR) and two complete responses (CR) have been detected in the CAR T-cell trials by Porter et al. and Kalos et al. (Kalos et al., 2011; Porter et al., 2011).
Active immunotherapy includes the following strategies: gene therapy, whole modified tumor cell vaccines, DC-based vaccines and tumor associated antigen (TAA)-derived peptide vaccines.
Approaches in gene therapy make use of autologous genetically modified tumor cells. These B-CLL cells are transfected with immuno-(co-)stimulatory genes like IL-2, IL-12, TNF-alpha, GM-CSF, CD80, CD40L, LFA-3 and ICAM-1 to improve antigen presentation and T cell activation (Carballido et al., 2012). While specific T-cell responses and reduction in tumor cells are readily observed, immune responses are only transient.
Several studies have used autologous DCs as antigen presenting cells to elicit anti-tumor responses. DCs have been loaded ex vivo with tumor associated peptides, whole tumor cell lysate and tumor-derived RNA or DNA. Another strategy uses whole tumor cells for fusion with DCs and generation of DC-B-CLL-cell hybrids. Transfected DCs initiated both CD4+ and CD8+ T-cell responses (Muller et al., 2004). Fusion hybrids and DCs loaded with tumor cell lysate or apoptotic bodies increased tumor-specific CD8+ T-cell responses. Patients that showed a clinical response had increased IL-12 serum levels and reduced numbers of Tregs (Palma et al., 2008).
Different approaches use altered tumor cells to initiate or increase CLL-specific immune responses. An example for this strategy is the generation of trioma cells: B-CLL cells are fused to anti-Fc receptor expressing hybridoma cells that have anti-APC specificity. Trioma cells induced CLL-specific T-cell responses in vitro (Kronenberger et al., 2008).
Another strategy makes use of irradiated autologous CLL cells with Bacillus Calmette-Guerin as an adjuvant as a vaccine. Several patients showed a reduction in leukocyte levels or stable disease (Hus et al., 2008).
Besides isolated CLL cells, whole blood from CLL patients has been used as a vaccine after preparation in a blood treatment unit. The vaccine elicited CLL-specific T-cell responses and led to partial clinical responses or stable disease in several patients (Spaner et al., 2005).
Several TAAs are over-expressed in CLL and are suitable for vaccinations. These include fibromodulin (Mayr et al., 2005), RHAMM/CD168 (Giannopoulos et al., 2006), MDM2 (Mayr et al., 2006), hTERT (Counter et al., 1995), the oncofetal antigen-immature laminin receptor protein (OFAiLRP) (Siegel et al., 2003), adipophilin (Schmidt et al., 2004), survivin (Granziero et al., 2001), KW1 to KW14 (Krackhardt et al., 2002) and the tumor-derived IgVHCDR3 region (Harig et al., 2001; Carballido et al., 2012). A phase I clinical trial was conducted using the RHAMM-derived R3 peptide as a vaccine. 5 of 6 patients had detectable R3-specific CD8+ T-cell responses (Giannopoulos et al., 2010).
Depending on the colorectal cancer (CRC) stage, different standard therapies are available for colon and rectal cancer. Standard procedures include surgery, radiation therapy, chemotherapy and targeted therapy for CRC (Berman et al., 2015a; Berman et al., 2015b).
Removal of the tumor is essential for the treatment of CRC. For chemotherapeutic treatment, the drugs capecitabine or 5-fluorouracil (5-FU) are used. For combinational chemotherapy, a cocktail containing 5-FU, leucovorin and oxaliplatin (FOLFOX) is recommended (Stintzing, 2014; Berman et al., 2015b), In addition to chemotherapeutic drugs, several monoclonal antibodies targeting the epidermal growth factor receptor (EGFR, cetuximab, panitumumab) or the vascular endothelial growth factor-A (VEGF-A, bevacizumab) are administered to patients with high stage disease. For second-line and later treatment the inhibitor for VEGF aflibercept, the tyrosine kinase inhibitor regorafenib and the thymidylate-synthetase inhibitor TAS-102 and the dUTPase inhibitor TAS-114 can be used (Stintzing, 2014; Wilson et al., 2014).
Latest clinical trials analyze active immunotherapy as a treatment option against CRC. Those strategies include the vaccination with peptides from tumor-associated antigens (TAAs), whole tumor cells, dendritic cell (DC) vaccines and viral vectors (Koido et al., 2013).
Peptide vaccines have so far been directed against carcinoembryonic antigen (CEA), mucin 1, EGFR, squamous cell carcinoma antigen recognized by T cells 3 (SART3), beta-human chorionic gonadotropin (beta-hCG), Wilms’ Tumor antigen 1 (WT1), Survivin-2B, MAGE3, p53, ring finger protein 43 and translocase of the outer mitochondrial membrane 34 (TOMM34), or mutated KRAS. In several phase I and II clinical trials patients showed antigen-specific CTL responses or antibody production. In contrast to immunological responses, many patients did not benefit from peptide vaccines on the clinical level (Koido et al., 2013; Miyagi et al., 2001; Moulton et al., 2002; Okuno et al., 2011).
Dendritic cell vaccines comprise DCs pulsed with either TAA-derived peptides, tumor cell lysates, apoptotic tumor cells, or tumor RNA or DC-tumor cell fusion products. While many patients in phase I/II trials showed specific immunological responses, only the minority had a clinical benefit (Koido et al., 2013).
Whole tumor cell vaccines consist of autologous tumor cells modified to secrete GM-CSF, modified by irradiation or virus-infected, irradiated cells. Most patients showed no clinical benefit in several phase II/III trials (Koido et al., 2013).
Vaccinia virus or replication-defective avian poxvirus encoding CEA as well as B7.1, ICAM-1 and LFA-3 have been used as vehicles in viral vector vaccines in phase I clinical trials. A different study used non-replicating canary pox virus encoding CEA and B7.1. Besides the induction of CEA-specific T cell responses 40% of patients showed objective clinical responses (Horig et al., 2000; Kaufman et al., 2008).
Immunotherapy may be a promising novel approach to treat advanced esophageal cancer. Several cancer-associated genes and cancer-testis antigens were shown to be over-expressed in esophageal cancer, including different MAGE genes, NY-ESO-1 and EpCAM (Kimura et al., 2007; Liang et al., 2005; Inoue et al., 1995; Bujas et al., 2011; Tanaka et al., 1997; Quillien et al., 1997). Those genes represent very interesting targets for immunotherapy and most of them are under investigation for the treatment of other malignancies (ClinicalTrials.gov, 2015). Furthermore, up-regulation of PD-L1 and PD-L2 was described in esophageal cancer, which correlated with poorer prognosis. Thus, esophageal cancer patients with PD-L1-positive tumors might benefit from anti-PD-L1 immunotherapy (Ohigashi et al., 2005).
Clinical data on immunotherapeutic approaches in esophageal cancer are still relatively scarce at present, as only a very limited number of early phase clinical trials have been completed. A vaccine consisting of three peptides derived from three different cancer-testis antigens (TTK protein kinase, lymphocyte antigen 6 complex locus K and insulin-like growth factor (IGF)-II mRNA binding protein 3) was administered to patients with advanced esophageal cancer in a phase I trial with moderate results. Intra-tumoral injection of activated T cells after in vitro challenge with autologous malignant cells elicited complete or partial tumor responses in four of eleven patients in a phase I/II study (Toomey et al., 2013). A vaccine consisting of three peptides derived from three different cancer-testis antigens (TTK protein kinase, lymphocyte antigen 6 complex locus K and insulin-like growth factor (IGF)-II mRNA binding protein 3) was administered to patients with advanced esophageal cancer in a phase I trial with moderate results (Kono et al., 2009). Intra-tumoral injection of activated T cells after in vitro challenge with autologous malignant cells and interleukin 2 elicited complete or partial tumor responses in four of eleven patients in a phase I/II study (Toh et al., 2000; Toh et al., 2002). Further clinical trials are currently performed to evaluate the impact of different immunotherapies on esophageal cancer, including adoptive cellular therapy (NCT01691625, NCT01691664, NCT01795976, NCT02096614, NCT02457650) vaccination strategies (NCT01143545, NCT01522820) and anti-PD-L1 therapy (NCT02340975) (ClinicalTrials.gov, 2015).
The efficacy of current therapeutic regimens for advanced GC is poor, resulting in low 5-year survival rates. Immunotherapy might be an alternative approach to ameliorate the survival of GC patients. Adoptive transfer of tumor-associated lymphocytes and cytokine induced killer cells, peptide-based vaccines targeting HER2/neu, MAGE-3 or vascular endothelial growth factor receptor 1 and 2 and dendritic cell-based vaccines targeting HER2/neu showed promising results in clinical GC trials. Immune checkpoint inhibition and engineered T cells might represent additional therapeutic options, which is currently evaluated in pre-clinical and clinical studies (Matsueda and Graham, 2014).
The therapeutic options for glioblastoma (WHO grade IV) are very limited. Different immunotherapeutic approaches are investigated for the treatment of GB, including immune-checkpoint inhibition, vaccination and adoptive transfer of engineered T cells.
Antibodies directed against inhibitory T cell receptors or their ligands were shown to efficiently enhance T cell-mediated anti-tumor immune responses in different cancer types, including melanoma and bladder cancer. The effects of T cell activating antibodies like ipilimumab and nivolumab are therefore assessed in clinical GB trials, but preliminary data indicate autoimmune-related adverse events.
Different vaccination strategies for GB patients are currently investigated, including peptide-based vaccines, heat-shock protein vaccines, autologous tumor cell vaccines, dendritic cell-based vaccines and viral protein-based vaccines. In these approaches peptides derived from GB-associated proteins like epidermal growth factor receptor variant III (EG-FRvIII) or heat shock proteins or dendritic cells pulsed with autologous tumor cell lysate or cytomegalo virus components are applied to induce an anti-tumor immune response in GB patients. Several of these studies reveal good safety and tolerability profiles as well as promising efficacy data.
Adoptive transfer of genetically modified T cells is an additional immunotherapeutic approach for the treatment of GB. Different clinical trials currently evaluate the safety and efficacy of chimeric antigen receptor bearing T cells directed against HER2, IL-13 receptor alpha 2 and EGFRvIII (Ampie et al., 2015).
Therapeutic options in advanced non-resectable HCC are limited to Sorafenib, a multi-tyrosine kinase inhibitor (Chang et al., 2007; Wilhelm et al., 2004). Sorafenib is the only systemic drug confirmed to increase survival by about 3 months and currently represents the only experimental treatment option for such patients (Chapiro et al., 2014; Llovet et al., 2008). Lately, a limited number of immunotherapy trials for HCC have been conducted. Cytokines have been used to activate subsets of immune cells and/or increase the tumor immunogenicity (Reinisch et al., 2002; Sangro et al., 2004). Other trials have focused on the infusion of Tumor-infiltrating lymphocytes or activated peripheral blood lymphocytes (Shi et al., 2004; Takayama et al., 1991; Takayama et al., 2000).
So far, a small number of therapeutic vaccination trials have been executed. Butterfield et al. conducted two trials using peptides derived from alpha-fetoprotein (AFP) as a vaccine or DCs loaded with AFP peptides ex vivo (Butterfield et al., 2003; Butterfield et al., 2006). In two different studies, autologous dendritic cells (DCs) were pulsed ex vivo with autologous tumor lysate (Lee et al., 2005) or lysate of the hepatoblastoma cell line HepG2 (Palmer et al., 2009). So far, vaccination trials have only shown limited improvements in clinical outcomes.
Enhancing the anti-tumor immune responses appears to be a promising strategy for the treatment of advanced melanoma. In the United States the immune checkpoint inhibitor ipilimumab as well as the BRAF kinase inhibitors vemurafenib and dabrafenib and the MEK inhibitor trametinib are already approved for the treatment of advanced melanoma. Both approaches increase the patient’s anti-tumor immunity – ipilimumab directly by reducing T cell inhibition and the kinase inhibitors indirectly by enhancing the expression of melanocyte differentiation antigens. Additional checkpoint inhibitors (nivolumab and lambrolizumab) are currently investigated in clinical studies with first encouraging results. Additionaly, different combination therapies targeting the anti-tumor immune response are tested in clinical trials including ipilimumab plus nivolumab, ipilimumab plus a gp100-derived peptide vaccine, ipilimumab plus dacarbazine, ipilimumab plus IL-2 and iplimumab plus GM-CSF (Srivastava and McDermott, 2014).
Several different vaccination approaches have already been evaluated in patients with advanced melanoma. So far, phase III trials revealed rather disappointing results and vaccination strategies clearly need to be improved. Therefore, new clinical trials, like the OncoVEX GM-CSF trial or the DERMA trial, aim at improving clinical efficacy without reducing tolerability.
Adoptive T cell transfer shows great promise for the treatment of advanced stage melanoma. In vitro expanded autologous tumor infiltrating lymphocytes as well as T cells harboring a high affinity T cell receptor for the cancer-testis antigen NY-ESO-1 had significant beneficial and low toxic effects upon transfer into melanoma patients. Unfortunately, T cells with high affinity T cell receptors for the melanocyte specific antigens MART1 and gp100 and the cancer-testis antigen MAGEA3 induced considerable toxic effects in clinical trials. Thus, adoptive T cell transfer has high therapeutic potential, but safety and tolerability of these treatments needs to be further increased (Phan and Rosenberg, 2013; Hinrichs and Restifo, 2013).
Because the disease has usually spread by the time it is discovered, radiation therapy and chemotherapy are often used, sometimes in combination with surgery (S3-Leitlinie Lungenkarzinom, 2011). To expand the therapeutic options for NSCLC, different immunotherapeutic approaches have been studied or are still under investigation. While vaccination with L-BLP25 or MAGEA3 failed to demonstrate a vaccine-mediated survival advantage in NSCLC patients, an allogeneic cell line-derived vaccine showed promising results in clinical studies. Additionally, further vaccination trials targeting gangliosides, the epidermal growth factor receptor and several other antigens are currently ongoing. An alternative strategy to enhance the patient’s anti-tumor T cell response consists of blocking inhibitory T cell receptors or their ligands with specific antibodies. The therapeutic potential of several of these antibodies, including ipilimumab, nivolumab, pembrolizumab, MPDL3280A and MEDI-4736, in NSCLC is currently evaluated in clinical trials (Reinmuth et al., 2015).
Immunotherapy appears to be a promising strategy to ameliorate the treatment of ovarian cancer patients, as the presence of pro-inflammatory tumor infiltrating lymphocytes, especially CD8-positive T cells, correlates with good prognosis and T cells specific for tumor-associated antigens can be isolated from cancer tissue.
Therefore, a lot of scientific effort is put into the investigation of different immunotherapies in ovarian cancer. A considerable number of pre-clinical and clinical studies have already been performed and further studies are currently ongoing. Clinical data are available for cytokine therapy, vaccination, monoclonal antibody treatment, adoptive cell transfer and immunomodulation.
Cytokine therapy with interleukin-2, interferon-alpha, interferon-gamma or granulocyte-macrophage colony stimulating factor aims at boosting the patient’s own anti-tumor immune response and these treatments have already shown promising results in small study cohorts.
Phase I and II vaccination studies, using single or multiple peptides, derived from several tumor-associated proteins (Her2/neu, NY-ESO-1, p53, Wilms tumor-1) or whole tumor antigens, derived from autologous tumor cells revealed good safety and tolerability profiles, but only low to moderate clinical effects.
Monoclonal antibodies that specifically recognize tumor-associated proteins are thought to enhance immune cell-mediated killing of tumor cells. The anti-CA-125 antibodies oregovomab and abagovomab as well as the anti-EpCAM antibody catumaxomab achieved promising results in phase II and III studies. In contrast, the anti-MUC1 antibody HMFG1 failed to clearly enhance survival in a phase III study.
An alternative approach uses monoclonal antibodies to target and block growth factor and survival receptors on tumor cells. While administration of trastuzumab (anti-HER2/neu antibody) and MOv18 and MORAb-003 (anti-folate receptor alpha antibodies) only conferred limited clinical benefit to ovarian cancer patients, addition of bevacizumab (anti-VEGF antibody) to the standard chemotherapy in advanced ovarian cancer appears to be advantageous.
Adoptive transfer of immune cells achieved heterogeneous results in clinical trials. Adoptive transfer of autologous, in vitro expanded tumor infiltrating T cells was shown to be a promising approach in a pilot trial. In contrast, transfer of T cells harboring a chimeric antigen receptor specific for folate receptor alpha did not induce a significant clinical response in a phase I trial. Dendritic cells pulsed with tumor cell lysate or tumor-associated proteins in vitro were shown to enhance the anti-tumor T cell response upon transfer, but the extent of T cell activation did not correlate with clinical effects. Transfer of natural killer cells caused significant toxicities in a phase II study.
Intrinsic anti-tumor immunity as well as immunotherapy are hampered by an immunosuppressive tumor microenvironment. To overcome this obstacle immunomodulatory drugs, like cyclophosphamide, anti-CD25 antibodies and pegylated liposomal doxorubicin are tested in combination with immunotherapy. Most reliable data are currently available for ipilimumab, an anti-CTLA4 antibody, which enhances T cell activity. Ipilimumab was shown to exert significant anti-tumor effects in ovarian cancer patients (Mantia-Smaldone et al., 2012).
Therapeutic options for pancreatic cancer patients are very limited. One major problem for effective treatment is the typically advanced tumor stage at diagnosis. Vaccination strategies are investigated as further innovative and promising alternative for the treatment of pancreatic cancer. Peptide-based vaccines targeting KRAS mutations, reactive telomerase, gastrin, survivin, CEA and MUC1 have already been evaluated in clinical trials, partially with promising results. Furthermore, clinical trials for dendritic cell-based vaccines, allogeneic GM-CSF-secreting vaccines and algenpantucel-L in pancreatic cancer patients also revealed beneficial effects of immunotherapy. Additional clinical trials further investigating the efficiency of different vaccination protocols are currently ongoing (Salman et al., 2013).
The dendritic cell-based vaccine sipuleucel-T was the first anti-cancer vaccine to be approved by the FDA. Due to its positive effect on survival in patients with CRPC, much effort is put into the development of further immunotherapies. Regarding vaccination strategies, the peptide vaccine prostate-specific antigen (PSA)-TRICOM, the personalized peptide vaccine PPV, the DNA vaccine pTVG-HP and the whole cell vaccine expressing GM-CSF GVAX showed promising results in different clinical trials. Furthermore, dendritic cell-based vaccines other than sipuleucel-T, namely BPX-101 and DCVAC/Pa were shown to elicited clinical responses in prostate cancer patients. Immune checkpoint inhibitors like ipilimumab and nivolumab are currently evaluated in clinical studies as monotherapy as well as in combination with other treatments, including androgen deprivation therapy, local radiation therapy, PSA-TRICOM and GVAX. The immunomodulatory substance tasquinimod, which significantly slowed progression and increased progression free survival in a phase II trial, is currently further investigated in a phase III trial. Lenalidomide, another immunomodulator, induced promising effects in early phase clinical studies, but failed to improve survival in a phase III trial. Despite these disappointing results further lenalidomide trials are ongoing (Quinn et al., 2015).
The known immunogenity of RCC has represented the basis supporting the use of immunotherapy and cancer vaccines in advanced RCC. The interesting correlation between lymphocytes PD-1 expression and RCC advanced stage, grade and prognosis, as well as the selective PD-L1 expression by RCC tumor cells and its potential association with worse clinical outcomes, have led to the development of new anti PD-1/PD-L1 agents, alone or in combination with anti-angiogenic drugs or other immunotherapeutic approaches, for the treatment of RCC Massari et al., 2015). In advanced RCC, a phase III cancer vaccine trial called TRIST study evaluates whether TroVax (a vaccine using a tumor-associated antigen 5T4, with a pox virus vector), added to first-line standard of care therapy, prolongs survival of patients with locally advanced or mRCC. Median survival had not been reached in either group with 399 patients (54%) remaining on study however analysis of the data confirms prior clinical results, demonstrating that TroVax is both immunologically active and that there is a correlation between the strength of the 5T4-specific antibody response and improved survival. Further there are several studies searching for peptide vaccines using epitopes being over-expressed in RCC.
Various approaches of tumor vaccines have been under investigation. Studies using whole-tumor approaches, including tumor cell lysates, fusions of dendritic cells with tumor cells, or whole-tumor RNA were done in RCC patients, and remissions of tumor lesions were reported in some of these trials (Avigan et al., 2004; Holtl et al., 2002; Marten et al., 2002; Su et al., 2003; Wittig et al., 2001).
Innovations occurred regarding detection, diagnosis and treatment of SCLC. It was shown that the usage of CT scans instead of x-rays for early cancer detection lowered the risk of death from lung cancer. Nowadays, the diagnosis of SCLC can be supported by fluorescence or virtual bronchoscopy; the real-time tumor imagining can be implemented by the radiation treatment. The novel anti-angiogenesis drugs like bevacizumab (Avastin), sunitinib (Sutent) and nintedanib (BIBF 1120) were shown to have therapeutically effects in treatment of SCLC (American Cancer Society, 2015). The immune therapy presents an excessively investigated field of cancer therapy. Various approaches are studded in the treatment of SCLC. One of the approaches targets the blocking of CTLA-4, a natural human immune suppressor. The inhibition of CTLA-4 intends to boost the immune system to combat the cancer. Recently, the development of promising immune check point inhibitors for treatment of SCLC has been started. Another approach is based on anti-cancer vaccines which is currently available for treatment of SCLC in clinical studies (American Cancer Society, 2015; National Cancer Institute (NCI), 2011).
One treatment option is targeting CD33 with antibody-drug conjugates (anti-CD33+calechiamicin, SGN-CD33a, anti-CD33+actinium-225), bispecific antibodies (recognition of CD33+CD3 (AMG 330) or CD33+CD16) and chimeric antigen receptors (CARs) (Estey, 2014).
Treatment of NHL depends on the histologic type and stage (National Cancer Institute, 2015). Spontaneous tumor regression can be observed in lymphoma patients. Therefore, active immunotherapy is a therapy option (Palomba, 2012). An important vaccination option includes Id vaccines. B lymphocytes express surface immunoglobulins with a specific amino acid sequence in the variable regions of their heavy and light chains, unique to each cell clone (=idiotype, Id). The idiotype functions as a tumor associated antigen. Passive immunization includes the injection of recombinant murine anti-Id monoclonal antibodies alone or in combination with IFNalpha, IL2 or chlorambucil.
Active immunization includes the injection of recombinant protein (Id) conjugated to an adjuvant (KLH), given together with GM-CSF as an immune adjuvant. Tumor-specific Id is produced by hybridoma cultures or using recombinant DNA technology (plasmids) by bacterial, insect or mammalian cell culture. Three phase III clinical trials have been conducted (Biovest, Genitope, Favrille). In two trials patients had received rituximab. GM-CSF was administered in all three trials. Biovest used hybridoma-produced protein, Genitope and Favrille used recombinant protein. In all three trials Id was conjugated to KLH. Only Biovest had a significant result.
Vaccines other than Id include the cancer-testis antigens MAGE, NY-ESO1 and PASD-1, the B-cell antigen CD20 or cellular vaccines. The latest mentioned consist of DCs pulsed with apoptotic tumor cells, tumor cell lysate, DC-tumor cell fusion or DCs pulsed with tumor-derived RNA. In situ vaccination involves the vaccination with intra-tumoral CpG in combination with chemotherapy or irradiated tumor cells grown in the presence of GM-CSF and collection/expansion/re-infusion of T cells. Vaccination with antibodies that alter immunologic checkpoints are comprised of anti-CD40, anti-OX40, anti-41 BB, anti-CD27, anti-GITR (agonist antibodies that directly enhance anti-tumor response) or anti-PD1, anti-CTLA-4 (blocking antibodies that inhibit the checkpoint that would hinder the immune response). Examples are ipilimumab (anti-CTLA-4) and CT-011 (anti-PD1) (Palomba, 2012).
There are also some immunotherapeutic approaches that are currently being tested. In a Phase I/II Clinical Trial patients suffering from uterine cancer were vaccinated with autologous dendritic cells (DCs) electroporated with Wilms’ tumor gene 1 (WT1) mRNA. Besides one case of local allergic reaction to the adjuvant, no adverse side effects were observed and 3 out of 6 patients showed an immunological response (Coosemans et al., 2013).
As stated above, HPV infections provoke lesions that may ultimately lead to cervical cancer. Therefore, the HPV viral oncoproteins E6 and E7 that are constitutively expressed in high-grade lesions and cancer and are required for the onset and maintenance of the malignant phenotype are considered promising targets for immunotherapeutic approaches (Hung et al., 2008; Vici et al., 2014). One study performed Adoptive T-cell therapy (ACT) in patients with metastatic cervical cancer. Patients receive an infusion with E6 and E7 reactive tumor-infiltrating T cells (TILs) resulting in complete regression in 2 and a partial response in 1 out of 9 patients (Stevanovic et al., 2015). Furthermore, an intracellular antibody targeting E7 was reported to block tumor growth in mice (Accardi et al., 2014). Also peptide, DNA and DC-based vaccines targeting HPV E6 and E7 are in clinical trials (Vici et al., 2014).
Cholangiocarcinoma (CCC) is mostly identified in advanced stages because it is difficult to diagnose. Gallbladder cancer (GBC) is the most common and aggressive malignancy of the biliary tract worldwide. As for GBC only 10% of tumors are resectable and even with surgery most progress to metastatic disease, prognosis is even worse than for CCC with a 5-year survival of less than 5%. Although most tumors are unresectable there is still no effective adjuvant therapy (Rakic et al., 2014). Some studies showed that combination of chemotherapeutic drugs or combination of targeted therapy (antiVEGFR/EGFR) with chemotherapy led to an increased overall survival and might be promising treatment options for the future (Kanthan et al., 2015). Due to the rarity of carcinomas of the biliary tract in general there are only a few GBC or CCC specific studies, while most of them include all biliary tract cancers. This is the reason why treatment did not improve during the last decades and RO resection still is the only curative treatment option.
The standard treatment for bladder cancer includes surgery, radiation therapy, chemotherapy and immunotherapy.
An effective immunotherapeutic approach is established in the treatment of aggressive non-muscle invasive bladder cancer (NMIBC). Thereby, a weakened form of the bacterium Mycobacterium bovis (bacillus Calmette-Guerin=BCG) is applied as an intravesical solution. The major effect of BCG treatment is a significant long-term (up to 10 years) protection from cancer recurrence and reduced progression rate. In principle, the treatment with BCG induces a local inflammatory response which stimulates the cellular immune response. The immune response to BCG is based on the following key steps: infection of urothelial and bladder cancer cells by BCG, followed by increased expression of antigen-presenting molecules, induction of immune response mediated via cytokine release, induction of antitumor activity via involvement of various immune cells (thereunder cytotoxic T lymphocytes, neutrophils, natural killer cells, and macrophages) (Fuge et al., 2015; Gandhi et al., 2013).
\BCG treatment is in general well tolerated by patients but can be fatal especially by the immunocompromised patients. BCG refractory is observed in about 30-40% of patients (Fuge et al., 2015; Steinberg et al., 2016a). The treatment of patients who failed the BCG therapy is challenging. The patients who failed the BCG treatment are at high risk for developing of muscle-invasive disease. Radical cystectomy is the preferable treatment option for non-responders (Steinberg et al., 2016b; von Rundstedt and Lerner, 2015). The FDA approved second line therapy of BCG-failed NMIBC for patients who desire the bladder preservation is the chemotherapeutic treatment with valrubicin. A number of other second line therapies are available or being currently under investigation as well, thereunder immunotherapeutic approaches like combined BCG-interferon or BCG-check point inhibitor treatments, pre-BCG transdermal vaccination, treatment with Mycobacterium phlei cell wall-nucleic acid (MCNA) complex, mono- or combination chemotherapy with various agents like mitomycin C, gemcitabine, docetaxel, nab-paclitaxel, epirubicin, mitomycin/gemcitabine, gemcitabine/docetaxel, and device-assisted chemotherapies like thermochemo-, radiochemo-, electromotive or photodynamic therapies (Fuge et al., 2015; Steinberg et al., 2016b; von Rundstedt and Lerner, 2015). Further evaluation of available therapies in clinical trials is still required.
The alternative treatment options for advanced bladder cancer are being investigated in ongoing clinical trials. The current clinical trials focused on the development of molecularly targeted therapies and immunotherapies. The targeted therapies investigate the effects of cancerogenesis related pathway inhibitors (i.e. mTOR, vascular endothelial, fibroblast, or epidermal growth factor receptors, anti-angiogenesis or cell cycle inhibitors) in the treatment of bladder cancer. The development of molecularly targeted therapies remains challenging due to high degree of genetic diversity of bladder cancer. The main focus of the current immunotherapy is the development of checkpoint blockage agents like anti-PD1 monoclonal antibody and adoptive T-cell transfer (Knollman et al., 2015; Grivas et al., 2015; Jones et al., 2016; Rouanne et al., 2016).
Head and neck squamous cell carcinomas (HNSCC) are heterogeneous tumors with differences in epidemiology, etiology and treatment (Economopoulou et al., 2016). Treatment for early HNSCC involves single-modality therapy with either surgery or radiation (World Health Organization, 2014). Advanced cancers are treated by a combination of chemotherapy with surgery and/or radiation therapy.
HNSCC is considered an immunosuppressive disease, characterized by the dysregulation of immunocompetent cells and impaired cytokine secretion (Economopoulou et al., 2016). Immunotherapeutic strategies differ between HPV-negative and HPV-positive tumors.
In HPV-positive tumors, the viral oncoproteins E6 and E7 represent good targets, as they are continuously expressed by tumor cells and are essential to maintain the transformation status of HPV-positive cancer cells. Several vaccination therapies are currently under investigation in HPV-positive HNSCC, including DNA vaccines, peptide vaccines and vaccines involving dendritic cells (DCs). Additionally, an ongoing phase II clinical trial investigates the efficacy of lymphodepletion followed by autologous infusion of TILs in patients with HPV-positive tumors (Economopoulou et al., 2016).
In HPV-negative tumors, several immunotherapeutic strategies are currently used and under investigation. The chimeric IgG1 anti-EGFR monoclonal antibody cetuximab has been approved by the FDA in combination with chemotherapy as standard first line treatment for recurring/metastatic HNSCC. Other anti-EGFR monoclonal antibodies, including panitumumab, nimotuzumab and zalutumumab, are evaluated in HNSCC. Several immune checkpoint inhibitors are investigated in clinical trials for their use in HNSCC. They include the following antibodies: Ipilimumab (anti-CTLA-4), tremelimumab (anti-CTLA-4), pembrolizumab (anti-PD-1), nivolumab (anti-PD-1), durvalumab (anti-PD-1), anti-KIR, urelumab (anti-CD137), and anti-LAG-3.
Two clinical studies with HNSCC patients evaluated the use of DCs loaded with p53 peptides or apoptotic tumor cells. The immunological responses were satisfactory and side effects were acceptable. Several studies have been conducted using adoptive T cell therapy (ACT). T cells were induced against either irradiated autologous tumor cells or EBV. Results in disease control and overall survival were promising (Economopoulou et al., 2016).
Considering the severe side-effects and expense associated with treating cancer, there is a need to identify factors that can be used in the treatment of cancer in general and glioblastoma (GB), breast cancer (BRCA), colorectal cancer (CRC), renal cell carcinoma (RCC), chronic lymphocytic leukemia (CLL), hepatocellular carcinoma (HCC), non-small cell and small cell lung cancer (NSCLC, SCLC), Non-Hodgkin lymphoma (NHL), acute myeloid leukemia (AML), ovarian cancer (OC), pancreatic cancer (PC), prostate cancer (PCA), esophageal cancer including cancer of the gastric-esophageal junction (OSCAR), gallbladder cancer and cholangiocarcinoma (GBC, CCC), melanoma (MEL), gastric cancer (GC), urinary bladder cancer (UBC), head and neck squamous cell carcinoma (HNSCC), and uterine cancer (UEC) in particular. There is also a need to identify factors representing biomarkers for cancer in general and the above-mentioned cancer types in particular, leading to better diagnosis of cancer, assessment of prognosis, and prediction of treatment success.
Immunotherapy of cancer represents an option of specific targeting of cancer cells while minimizing side effects. Cancer immunotherapy makes use of the existence of tumor associated antigens.
The current classification of tumor associated antigens (TAAs) comprises the following major groups:
a) Cancer-testis antigens: The first TAAs ever identified that can be recognized by T cells belong to this class, which was originally called cancer-testis (CT) antigens because of the expression of its members in histologically different human tumors and, among normal tissues, only in spermatocytes/spermatogonia of testis and, occasionally, in placenta. Since the cells of testis do not express class I and II HLA molecules, these antigens cannot be recognized by T cells in normal tissues and can therefore be considered as immunologically tumor-specific. Well-known examples for CT antigens are the MAGE family members and NY-ESO-1. b) Differentiation antigens: These TAAs are shared between tumors and the normal tissue from which the tumor arose. Most of the known differentiation antigens are found in melanomas and normal melanocytes. Many of these melanocyte lineage-related proteins are involved in biosynthesis of melanin and are therefore not tumor specific but nevertheless are widely used for cancer immunotherapy. Examples include, but are not limited to, tyrosinase and Melan-A/MART-1 for melanoma or PSA for prostate cancer. c) Over-expressed TAAs: Genes encoding widely expressed TAAs have been detected in histologically different types of tumors as well as in many normal tissues, generally with lower expression levels. It is possible that many of the epitopes processed and potentially presented by normal tissues are below the threshold level for T-cell recognition, while their over-expression in tumor cells can trigger an anticancer response by breaking previously established tolerance. Prominent examples for this class of TAAs are Her-2/neu, survivin, telomerase, or WT1. d) Tumor-specific antigens: These unique TAAs arise from mutations of normal genes (such as beta.-catenin, CDK4, etc.). Some of these molecular changes are associated with neoplastic transformation and/or progression. Tumor-specific antigens are generally able to induce strong immune responses without bearing the risk for autoimmune reactions against normal tissues. On the other hand, these TAAs are in most cases only relevant to the exact tumor on which they were identified and are usually not shared between many individual tumors. Tumor-specificity (or -association) of a peptide may also arise if the peptide originates from a tumor-(-associated) exon in case of proteins with tumor-specific (-associated) isoforms. e) TAAs arising from abnormal post-translational modifications: Such TAAs may arise from proteins which are neither specific nor overexpressed in tumors but nevertheless become tumor associated by posttranslational processes primarily active in tumors. Examples for this class arise from altered glycosylation patterns leading to novel epitopes in tumors as for MUC1 or events like protein splicing during degradation which may or may not be tumor specific. f) Oncoviral proteins: These TAAs are viral proteins that may play a critical role in the oncogenic process and, because they are foreign (not of human origin), they can evoke a T-cell response. Examples of such proteins are the human papilloma type 16 virus proteins, E6 and E7, which are expressed in cervical carcinoma.
An antigenic fragment is a polypeptide having an amino acid sequence that entirely is the same as part but not all of the amino acid sequence of one of the polypeptides. The antigenic fragment can be “free-standing,” or comprised within a larger polypeptide of which they form a part or region, most preferably as a single continuous region.
In some embodiments, the antigenic fragments include, for example, truncation polypeptides having the amino acid sequence of the polypeptides, except for deletion of a continuous series of residues that includes the amino terminus, or a continuous series of residues that includes the carboxyl terminus or deletion of two continuous series of residues, one including the amino terminus and one including the carboxyl terminus. In some embodiments, fragments are characterized by structural or functional attributes such as fragments that comprise alpha-helix and alpha-helix forming regions, beta-sheet and beta-sheet-forming regions, turn and turn-forming regions, coil and coil-forming regions, hydrophilic regions, hydrophobic regions, alpha amphipathic regions, beta amphipathic regions, flexible regions, surface-forming regions, and high antigenic index regions.
The fragment can be of any size. An antigenic fragment is capable of inducing an immune response in a subject or be recognized by a specific antibody. In some embodiments, the fragment corresponds to an amino-terminal truncation mutant. In some embodiments, the number of amino terminal amino acids missing from the fragment ranges from 1-100 amino acids. In some embodiments, it ranges from 1-75 amino acids, 1-50 amino acids , 40 amino acids, 1-30 amino acids, 1-25 amino acids, 1-20 amino acids, 1-15 amino acids, 1-10 amino acids and 1-5 amino acids.
In some embodiments, the fragment corresponds to carboxyl-terminal truncation mutant. In some embodiments, the number of carboxyl terminal amino acids missing from the fragment ranges from 1-100 amino acids. In some embodiments, it ranges from 1-75 amino acids, 1-50 amino acids, 1-40 amino acids, 1-30 amino acids, 1-25 amino acids, 1-20 amino acids, 1-15 amino acids, 1-10 amino acids and 1-5 amino acids.
In some embodiments, the fragment corresponds to an internal fragment that lacks both the amino and carboxyl terminal amino acids. In some embodiments, the fragment is 7-200 amino acid residues in length. In some embodiments, the fragment is 10-100 amino acid residues, 15-85 amino acid residues, 25-65 amino acid residues or 30-50 amino acid residues in length. In some embodiments, the fragment is 7 amino acids, 10 amino acids, 12 amino acids, 15 amino acids, 20 amino acids, 25 amino acids, 30 amino acids, 35 amino acids, 40 amino acids, 45 amino acids, 50 amino acids 55 amino acids, 60 amino acids, 80 amino acids or 100 amino acids in length.
In some embodiments, the fragment is at least 50 amino acids, 100 amino acids, 150 amino acids, 200 amino acids or at least 250 amino acids in length. Of course, larger antigenic fragments are also useful according to the present invention, as are fragments corresponding to most, if not all, of the amino acid sequence of the polypeptides described herein.
In some embodiments, the polypeptides have an amino acid sequence at least 80, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to the polypeptides described herein or antigenic fragments thereof. In some embodiments, the variants are those that vary from the reference by conservative amino acid substitutions, i.e., those that substitute a residue with another of like characteristics. Typical substitutions are among Ala, Val, Leu and Ile; among Ser and Thr; among the acidic residues Asp and Glu; among Asn and Gln; and among the basic residues Lys and Arg, or aromatic residues Phe and Tyr. In some embodiments, the polypeptides are variants in which several, 5 to 10, 1 to 5, or 1 to 2 amino acids are substituted, deleted, or added in any combination.
In some embodiments, the polypeptides are encoded by polynucleotides that are optimized for high level expression in E.coli. using codons that are preferred in E.coli. As used herein, a codon that is “optimized for high level expression in Salmonella” refers to a codon that is relatively more abundant in E.coli. in comparison with all other codons corresponding to the same amino acid. In some embodiments, at least 10% of the codons are optimized for high level expression in E.coli. In some embodiments, at least 25%, at least 50%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% of the codons are optimized for high level expression in E.coli.
In some embodiments, the polypeptide or antigenic fragment thereof comprises a cleavable protein sequence and/or affinity tag to aid in purification. In some embodiments, the affinity tag comprises at least 6 histidine residues. In some embodiments, the polypeptide or antigenic fragment thereof comprises a secretion signal to facilitate secretion of the protein through plasma membrane. In some embodiments, the secretion signal is a lysozyme secretion signal.
In some embodiments, the compositions are administered as pharmaceutical compositions and induce an immune response to the antigen in a cell, tissue or animal (e.g., a human). As used herein, an “antigenic composition” (which alternatively may be referred to as an “immunizing composition”) may comprise an antigen (e.g., a protein, peptide, or polypeptide). In some embodiments, the antigenic composition comprises a nucleic acid encoding a polypeptide antigen.
In some embodiments, the immunogenic composition or vaccine comprises at least one adjuvant. In other embodiments, the antigenic composition is in a mixture that comprises an additional immunostimulatory agent or nucleic acids encoding such an agent. Immunostimulatory agents include but are not limited to an additional antigen, an immunomodulator, an antigen presenting cell or an adjuvant. In other embodiments, one or more of the additional agent(s) is covalently bonded to the antigen or an immunostimulatory agent, in any combination. In certain embodiments, the antigenic composition is conjugated to or comprises an HLA anchor motif amino acids.
In certain embodiments, an antigenic composition can be used as an effective vaccine in inducing an anti-cancer humoral and/or cell-mediated immune response in an animal, including a human. The present invention contemplates one or more antigenic compositions or vaccines for use in both active and passive immunization embodiments.
A vaccine or immunizing composition of the present invention may vary in its composition of proteinaceous components. It will be understood that various compositions described herein may further comprise additional components. For example, one or more vaccine or immunogenic composition components may be comprised in a lipid or liposome. In another non-limiting example, a vaccine or immunogenic composition may comprise one or more adjuvants. A vaccine or immunizing composition of the present disclosure, and its various components, may be prepared by any method disclosed herein or as would be known to one of ordinary skill in the art, in light of the present disclosure.
It is understood that an immunizing composition may be made by a method that is well known in the art, including but not limited to chemical synthesis by solid phase synthesis and purification away from the other products of the chemical reactions by HPLC, or production by the expression of a nucleic acid sequence (e.g., a DNA sequence) encoding a peptide or polypeptide comprising an antigen of the present invention in an in vitro translation system or in a living cell including, for example, in a yeast cell, bacterial, mammalian cells or baculovirus/insect cells. The antigenic composition may be isolated and extensively purified to remove one or more undesired small molecular weight molecules and/or lyophilized for more ready formulation into a desired vehicle. It is further understood that amino acid additions, deletions, mutations, chemical modification and such like that are made in an antigenic composition component, such as a vaccine, will preferably not substantially interfere with the antibody recognition of the epitopic sequence.
In some embodiments, a peptide or polypeptide corresponding to a cancer antigen may generally be 10-20 amino acid residues in length, and may contain more than one peptide determinants or up to about 30-50 residues or so. In some embodiments, the polypeptide is between 10 and about 150 residues or more in length. A peptide sequence may be made by methods known to those of ordinary skill in the art, such as, for example, peptide synthesis using automated peptide synthesis machines, such as those available from Applied Biosystems (Foster City, Calif.).
In some embodiments, longer peptides or polypeptides also may be prepared, e.g., by recombinant means. In certain embodiments, a nucleic acid encoding an antigenic composition and/or a component described herein may be used, for example, to produce an antigenic composition in vitro or in vivo for the various compositions and methods of the present invention. For example, in certain embodiments, a nucleic acid encoding an antigen is comprised in, for example, a vector in a recombinant cell. The nucleic acid may be expressed to produce a peptide or polypeptide comprising an antigenic sequence. The peptide or polypeptide may be secreted from the cell, or comprised as part of or within the cell.
As modifications and changes may be made in the structure of an antigenic composition of the present disclosure, and still obtain molecules having like or otherwise desirable characteristics, such immunologically functional equivalents are also encompassed within the present invention.
For example, certain amino acids may be substituted for other amino acids in a peptide, polypeptide or protein structure without appreciable loss of interactive binding capacity with structures such as, for example, antigen-binding regions of antibodies, binding sites on substrate molecules or receptors, DNA binding sites, or such like. Since it is the interactive capacity and nature of a peptide, polypeptide or protein that defines its biological (e.g., immunological) functional activity, certain amino acid sequence substitutions can be made in an amino acid sequence (or, of course, its underlying DNA coding sequence) and nevertheless obtain a peptide or polypeptide with like (agonistic) properties. It is thus contemplated by the inventors that various changes may be made in the sequence of an antigenic composition such as, for example a cancer antigen peptide or polypeptide without appreciable loss of biological utility or activity. In particular cases, one or more of the potential glycosylation sites of the antigen can be mutated or deleted and in particular embodiments there is also one or more other amino acids that are modified compared to the corresponding wild-type sequence.
As used herein, an “amino molecule” refers to any amino acid, amino acid derivative or amino acid mimic as would be known to one of ordinary skill in the art. In certain embodiments, the residues of the antigenic composition comprises amino molecules that are sequential, without any non-amino molecule interrupting the sequence of amino molecule residues. In other embodiments, the sequence may comprise one or more non-amino molecule moieties. In particular embodiments, the sequence of residues of the antigenic composition may be interrupted by one or more non-amino molecule moieties.
Accordingly, antigenic compositions may encompass an amino molecule sequence comprising at least one of the 20 common amino acids in naturally synthesized proteins, or at least one modified or unusual amino acid.
In terms of variants that are immunologically functional equivalents, it is well understood by the skilled artisan that, inherent in the definition is the concept that there is a limit to the number of changes that may be made within a defined portion of the molecule and still result in a molecule with an acceptable level of equivalent immunological activity. An immunologically functional equivalent peptide or polypeptide are thus defined herein as those peptide(s) or polypeptide(s) in which certain, not most or all, of the amino acid(s) may be substituted.
In particular, where a shorter length peptide is concerned, it is contemplated that fewer amino acid substitutions should be made within the given peptide. A longer polypeptide may have an intermediate number of changes. The full length protein will have the most tolerance for a larger number of changes. Of course, a plurality of distinct polypeptides/peptides with different substitutions may easily be made and used in accordance with the invention.
It also is well understood that where certain residues are shown to be particularly important to the immunological or structural properties of a protein or peptide, e.g., residues in binding regions or active sites, such residues may not generally be exchanged. This is an important consideration in the present invention, where changes in the antigenic site should be carefully considered and subsequently tested to ensure maintenance of immunological function (e.g., antigenicity), where maintenance of immunological function is desired. In this manner, functional equivalents are defined herein as those peptides or polypeptides which maintain a substantial amount of their native immunological activity.
Amino acid substitutions are generally based on the relative similarity of the amino acid side-chain substituents, for example, their hydrophobicity, hydrophilicity, charge, size, and the like. An analysis of the size, shape and type of the amino acid side-chain substituents reveals that arginine, lysine and histidine are all positively charged residues; that alanine, glycine and serine are all a similar size; and that phenylalanine, tryptophan and tyrosine all have a generally similar shape. Therefore, based upon these considerations, arginine, lysine and histidine; alanine, glycine and serine; and phenylalanine, tryptophan and tyrosine; are defined herein as immunologically functional equivalents.
To effect more quantitative changes, the hydropathic index of amino acids may be considered. Each amino acid has been assigned a hydropathic index on the basis of their hydrophobicity and charge characteristics, these are: isoleucine (+4.5); valine (+4.2); leucine (+3.8); phenylalanine (+2.8); cysteine/cystine (+2.5); methionine (+1.9); alanine (+1.8); glycine (-0.4); threonine (-0.7); serine (-0.8); tryptophan (-0.9); tyrosine (-1.3); proline (-1.6); histidine (-3.2); glutamate (-3.5); glutamine (-3.5); aspartate (-3.5); asparagine (-3.5); lysine (-3.9); and arginine (-4.5).
The importance of the hydropathic amino acid index in conferring interactive biological function on a protein, polypeptide or peptide is generally understood in the art (Kyte & Doolittle, 1982, incorporated herein by reference). It is known that certain amino acids may be substituted for other amino acids having a similar hydropathic index or score and still retain a similar biological activity. In making changes based upon the hydropathic index, the substitution of amino acids whose hydropathic indices are within ±2 is preferred, those which are within ±1 are particularly preferred, and those within ±0.5 are even more particularly preferred.
It also is understood in the art that the substitution of like amino acids can be made effectively on the basis of hydrophilicity, particularly where the immunological functional equivalent polypeptide or peptide thereby created is intended for use in immunological embodiments, as in certain embodiments of the present invention. U.S. Pat. No. 4,554,101, incorporated herein by reference, states that the greatest local average hydrophilicity of a protein, as governed by the hydrophilicity of its adjacent amino acids, correlates with its immunogenicity and antigenicity, i.e. with a immunological property of the protein.
As detailed in U.S. Pat. No. 4,554,101, the following hydrophilicity values have been assigned to amino acid residues: arginine (+3.0); lysine (+3.0); aspartate (+3.0.+-0.1); glutamate (+3.0.+-.1); serine (+0.3); asparagine (+0.2); glutamine (+0.2); glycine (0); threonine (-0.4); proline (-0.5.+-0.1); alanine (-0.5); histidine (-0.5); cysteine (-1.0); methionine (-1.3); valine (-1.5); leucine (-1.8); isoleucine (-1.8); tyrosine (-2.3); phenylalanine (-2.5); tryptophan (-3.4).
In making changes based upon similar hydrophilicity values, the substitution of amino acids whose hydrophilicity values are within ±2 is preferred, those which are within ±1 are particularly preferred, and those within ±0.5 are even more particularly preferred.
Numerous scientific publications have also been devoted to the prediction of secondary structure, and to the identification of an epitope, from analyses of an amino acid sequence (Chou & Fasman, 1974a,b; 1978a,b, 1979). Any of these may be used, if desired, to supplement the teachings of U.S. Pat. No. 4,554,101.
Moreover, computer programs are currently available to assist with predicting an antigenic portion and an epitopic core region of one or more proteins, polypeptides or peptides. Examples include those programs based upon the Jameson-Wolf analysis (Jameson & Wolf, 1988; Wolf et al., 1988), the program PepPlot (Brutlag et al., 1990; Weinberger et al., 1985), and other new programs for protein tertiary structure prediction (Fetrow & Bryant, 1993). Another commercially available software program capable of carrying out such analyses is MacVector (IBI, New Haven, Conn.).
In further embodiments, major antigenic determinants of a peptide or polypeptide may be identified by an empirical approach in which portions of a nucleic acid encoding a peptide or polypeptide are expressed in a recombinant host, and the resulting peptide(s) or polypeptide(s) tested for their ability to elicit an immune response. For example, PCR can be used to prepare a range of peptides or polypeptides lacking successively longer fragments of the C-terminus of the amino acid sequence. The immunoactivity of each of these peptides or polypeptides is determined to identify those fragments or domains that are immunodominant. Further studies in which only a small number of amino acids are removed at each iteration then allows the location of the antigenic determinant(s) of the peptide or polypeptide to be more precisely determined.
Another method for determining a major antigenic determinant of a peptide or polypeptide is the SPOTs system (Genosys Biotechnologies, Inc., The Woodlands, Tex.). In this method, overlapping peptides are synthesized on a cellulose membrane, which following synthesis and deprotection, is screened using a polyclonal or monoclonal antibody. An antigenic determinant of the peptides or polypeptides which are initially identified can be further localized by performing subsequent syntheses of smaller peptides with larger overlaps, and by eventually replacing individual amino acids at each position along the immunoreactive sequence.
Once one or more such analyses are completed, an antigenic composition, such as for example a peptide or a polypeptide is prepared that contain at least the essential features of one or more antigenic determinants. An antigenic composition is then employed in the generation of antisera against the composition, and preferably the antigenic determinant(s).
While discussion has focused on functionally equivalent polypeptides arising from amino acid changes, it will be appreciated that these changes may be effected by alteration of the encoding DNA; taking into consideration also that the genetic code is degenerate and that two or more codons may code for the same amino acid. Nucleic acids encoding these antigenic compositions also can be constructed and inserted into one or more expression vectors by standard methods (Sambrook et al., 1987), for example, using PCR cloning methodology.
In addition to the peptidyl compounds described herein, the inventors also contemplate that other sterically similar compounds may be formulated to mimic the key portions of the peptide or polypeptide structure or to interact specifically with, for example, an antibody. Such compounds, which may be termed peptidomimetics, may be used in the same manner as a peptide or polypeptide of the invention and hence are also immunologically functional equivalents.
Certain mimetics that mimic elements of protein secondary structure are described in Johnson et al. (1993). The underlying rationale behind the use of peptide mimetics is that the peptide backbone of proteins exists chiefly to orientate amino acid side chains in such a way as to facilitate molecular interactions, such as those of antibody and antigen. A peptide mimetic is thus designed to permit molecular interactions similar to the natural molecule.
In particular embodiments, an antigenic composition is mutated for purposes such as, for example, enhancing its immunogenicity or producing or identifying a immunologically functional equivalent sequence. Methods of mutagenesis are well known to those of skill in the art (Sambrook et al., 1987).
As used herein, the term “oligonucleotide directed mutagenesis procedure” refers to template-dependent processes and vector-mediated propagation which result in an increase in the concentration of a specific nucleic acid molecule relative to its initial concentration, or in an increase in the concentration of a detectable signal, such as amplification. As used herein, the term “oligonucleotide directed mutagenesis procedure” is intended to refer to a process that involves the template-dependent extension of a primer molecule. The term template dependent process refers to nucleic acid synthesis of an RNA or a DNA molecule wherein the sequence of the newly synthesized strand of nucleic acid is dictated by the well-known rules of complementary base pairing (see, for example, Watson, 1987). Typically, vector mediated methodologies involve the introduction of the nucleic acid fragment into a DNA or RNA vector, the clonal amplification of the vector, and the recovery of the amplified nucleic acid fragment. Examples of such methodologies are provided by U.S. Pat. No. 4,237,224, specifically incorporated herein by reference in its entirety.
In some embodiments, site directed mutagenesis is used. Site-specific mutagenesis is a technique useful in the preparation of an antigenic composition, through specific mutagenesis of the underlying DNA. In general, the technique of site-specific mutagenesis is well known in the art. The technique further provides a ready ability to prepare and test sequence variants, incorporating one or more of the foregoing considerations, by introducing one or more nucleotide sequence changes into the DNA. Site-specific mutagenesis allows the production of a mutant through the use of specific oligonucleotide sequence(s) which encode the DNA sequence of the desired mutation, as well as a sufficient number of adjacent nucleotides, to provide a primer sequence of sufficient size and sequence complexity to form a stable duplex on both sides of the position being mutated. Typically, a primer of about 17 to about 75 nucleotides in length is preferred, with about 10 to about 25 or more residues on both sides of the position being altered, while primers of about 17 to about 25 nucleotides in length being more preferred, with about 5 to 10 residues on both sides of the position being altered.
In general, site-directed mutagenesis is performed by first obtaining a single-stranded vector, or melting of two strands of a double stranded vector which includes within its sequence a DNA sequence encoding the desired protein. As will be appreciated by one of ordinary skill in the art, the technique typically employs a bacteriophage vector that exists in both a single stranded and double stranded form. Typical vectors useful in site-directed mutagenesis include vectors such as the M13 phage. These phage vectors are commercially available and their use is generally well known to those skilled in the art. Double stranded plasmids are also routinely employed in site directed mutagenesis, which eliminates the step of transferring the gene of interest from a phage to a plasmid.
This mutagenic primer is then annealed with the single-stranded DNA preparation, and subjected to DNA polymerizing enzymes such as, for example, E.coli polymerase I Klenow fragment, in order to complete the synthesis of the mutation-bearing strand. Thus, a heteroduplex is formed wherein one strand encodes the original non-mutated sequence and the second strand bears the desired mutation. This heteroduplex vector is then used to transform appropriate cells, such as E.coli cells, and clones are selected that include recombinant vectors bearing the mutated sequence arrangement.
Alternatively, a pair of primers may be annealed to two separate strands of a double stranded vector to simultaneously synthesize both corresponding complementary strands with the desired mutation(s) in a PCR reaction. A genetic selection scheme to enrich for clones incorporating the mutagenic oligonucleotide has been devised (Kunkel et al., 1987). Alternatively, the use of PCR with commercially available thermostable enzymes such as Taq polymerase may be used to incorporate a mutagenic oligonucleotide primer into an amplified DNA fragment that can then be cloned into an appropriate cloning or expression vector (Tomic et al., 1990; Upender et al., 1995). A PCR.TM. employing a thermostable ligase in addition to a thermostable polymerase also may be used to incorporate a phosphorylated mutagenic oligonucleotide into an amplified DNA fragment that may then be cloned into an appropriate cloning or expression vector (Michael 1994).
The preparation of sequence variants of the selected gene using site-directed mutagenesis is provided as a means of producing potentially useful species and is not meant to be limiting, as there are other ways in which sequence variants of genes may be obtained. For example, recombinant vectors encoding the desired gene may be treated with mutagenic agents, such as hydroxylamine, to obtain sequence variants.
Additionally, one particularly useful mutagenesis technique is alanine scanning mutagenesis in which a number of residues are substituted individually with the amino acid alanine so that the effects of losing side-chain interactions can be determined, while minimizing the risk of large-scale perturbations in protein conformation (Cunningham et al., 1989).
In a further embodiment of the invention, one or more vaccine or immunizing composition components may be entrapped in a lipid complex such as, for example, a liposome. Liposomes are vesicular structures characterized by a phospholipid bilayer membrane and an inner aqueous medium. Multilamellar liposomes have multiple lipid layers separated by aqueous medium. They form spontaneously when phospholipids are suspended in an excess of aqueous solution. The lipid components undergo self-rearrangement before the formation of closed structures and entrap water and dissolved solutes between the lipid bilayers (Ghosh and Bachhawat, 1991).
In any case, a vaccine component (e.g., an antigenic peptide or polypeptide) may be isolated and/or purified from the chemical synthesis reagents, cell or cellular components. In a method of producing the vaccine or immunogenic composition component, purification is accomplished by any appropriate technique that is described herein or well-known to those of skill in the art (e.g., Sambrook et al., 1987). There is no general requirement that an antigenic composition of the present invention or other vaccine component always be provided in their most purified state. Indeed, it is contemplated that less substantially purified vaccine or immunogenic composition component, which is nonetheless enriched in the desired compound, relative to the natural state, will have utility in certain embodiments, such as, for example, total recovery of protein product, or in maintaining the activity of an expressed protein. However, it is contemplated that inactive products also have utility in certain embodiments, such as, e.g., in determining antigenicity via antibody generation.
The present invention also provides purified, and in certain embodiments, substantially purified vaccines or immunogenic composition components. The term “purified vaccine component” or “purified immunogenic composition component” as used herein, is intended to refer to at least one respective vaccine or immunogenic composition component (e.g., a proteinaceous composition, isolatable from cells), wherein the component is purified to any degree relative to its naturally-obtainable state, e.g., relative to its purity within a cellular extract or reagents of chemical synthesis. In certain aspects wherein the vaccine component is a proteinaceous composition, a purified vaccine component also refers to a wild-type or mutant protein, polypeptide, or peptide free from the environment in which it naturally occurs.
Where the term “substantially purified” is used, this will refer to a composition in which the specific compound (e.g., a protein, polypeptide, or peptide) forms the major component of the composition, such as constituting about 50% of the compounds in the composition or more. In preferred embodiments, a substantially purified vaccine component will constitute more than about 60%, about 70%, about 80%, about 90%, about 95%, about 99% or even more of the compounds in the composition.
In certain embodiments, a vaccine or immunogenic composition component may be purified to homogeneity. As applied to the present invention, “purified to homogeneity,” means that the vaccine component has a level of purity where the compound is substantially free from other chemicals, biomolecules or cells. For example, a purified peptide, polypeptide or protein will often be sufficiently free of other protein components so that degradative sequencing may be performed successfully. Various methods for quantifying the degree of purification of a vaccine component will be known to those of skill in the art in light of the present disclosure. These include, for example, determining the specific protein activity of a fraction (e.g., antigenicity), or assessing the number of polypeptides within a fraction by gel electrophoresis.
Various techniques suitable for use in chemical, biomolecule or biological purification, well known to those of skill in the art, may be applicable to preparation of a vaccine component of the present invention. These include, for example, precipitation with ammonium sulfate, PEG, antibodies and the like or by heat denaturation, followed by centrifugation; fractionation, chromatographic procedures, including but not limited to, partition chromatograph (e.g., paper chromatograph, thin-layer chromatograph (TLC), gas-liquid chromatography and gel chromatography) gas chromatography, high performance liquid chromatography, affinity chromatography, supercritical flow chromatography ion exchange, gel filtration, reverse phase, hydroxylapatite, lectin affinity; isoelectric focusing and gel electrophoresis (see for example, Sambrook et al. 1989; and Freifelder, Physical Biochemistry, Second Edition, pages 238-246, incorporated herein by reference).
Given many DNA and proteins are known (see for example, the National Center for Biotechnology Information’s GenBank and GenPept databases, or may be identified and amplified using the methods described herein, any purification method for recombinately expressed nucleic acid or proteinaceous sequences known to those of skill in the art can now be employed. In certain aspects, a nucleic acid may be purified on polyacrylamide gels, and/or cesium chloride centrifugation gradients, or by any other means known to one of ordinary skill in the art (see for example, Sambrook et al. 1989, incorporated herein by reference). In further aspects, a purification of a proteinaceous sequence may be conducted by recombinately expressing the sequence as a fusion protein. Such purification methods are routine in the art. This is exemplified by the generation of an specific protein-glutathione S-transferase fusion protein, expression in E.coli, and isolation to homogeneity using affinity chromatography on glutathione-agarose or the generation of a polyhistidine tag on the N- or C-terminus of the protein, and subsequent purification using Ni-affinity chromatography. In particular aspects, cells or other components of the vaccine may be purified by flow cytometry. Flow cytometry involves the separation of cells or other particles in a liquid sample, and is well known in the art (see, for example, U.S. Pat. Nos. 3,826,364, 4,284,412, 4,989,977, 4,498,766, 5,478,722, 4,857,451, 4,774,189, 4,767,206, 4,714,682, 5,160,974 and 4,661,913). Any of these techniques described herein, and combinations of these and any other techniques known to skilled artisans, may be used to purify and/or assay the purity of the various chemicals, proteinaceous compounds, nucleic acids, cellular materials and/or cells that may comprise a vaccine of the present invention. As is generally known in the art, it is believed that the order of conducting the various purification steps may be changed, or that certain steps may be omitted, and still result in a suitable method for the preparation of a substantially purified antigen or other vaccine component.
It is contemplated that an antigenic composition of the invention may be combined with one or more additional components to form a more effective composition or vaccine. Non-limiting examples of additional components include, for example, one or more additional antigens, immunomodulators or adjuvants to stimulate an immune response to an antigenic composition of the present invention and/or the additional component(s).
For example, in some embodiments one or more immunomodulators can be included in the vaccine to augment a cell’s or a patient’s (e.g., an animal’s) response. Immunomodulators can be included as purified proteins, nucleic acids encoding immunomodulators, and/or cells that express immunomodulators in the vaccine composition, for example. The following sections list non-limiting examples of immunomodulators that are of interest, and it is contemplated that various combinations of immunomodulators may be used in certain embodiments (e.g., a cytokine and a chemokine).
Interleukins, cytokines, nucleic acids encoding interleukins or cytokines, and/or cells expressing such compounds are contemplated as possible vaccine components. Interleukins and cytokines, include but are not limited to interleukin 1 (IL-1), IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-11, IL-12, IL-13, IL-14, IL-15, IL-18, .beta.-interferon, α-interferon, γ-interferon, angiostatin, thrombospondin, endostatin, GM-CSF, G-CSF, M-CSF, METH-1, METH-2, tumor necrosis factor, TGFβ, LT and combinations thereof.
Chemokines, nucleic acids that encode for chemokines, and/or cells that express such also may be used as vaccine components. Chemokines generally act as chemoattractants to recruit immune effector cells to the site of chemokine expression. It may be advantageous to express a particular chemokine coding sequence in combination with, for example, a cytokine coding sequence, to enhance the recruitment of other immune system components to the site of treatment. Such chemokines include, for example, RANTES, MCAF, MIP1-alpha, MIP1-Beta, IP-10 and combinations thereof. The skilled artisan will recognize that certain cytokines are also known to have chemoattractant effects and could also be classified under the term chemokines.
In certain embodiments, an antigenic composition may be chemically coupled to a carrier or recombinantly expressed with an immunogenic carrier peptide or polypetide (e.g., an antigen-carrier fusion peptide or polypeptide) to enhance an immune reaction. Exemplary and preferred immunogenic carrier amino acid sequences include hepatitis B surface antigen, keyhole limpet hemocyanin (KLH) and bovine serum albumin (BSA). Other albumins such as ovalbumin, mouse serum albumin or rabbit serum albumin also can be used as immunogenic carrier proteins. Means for conjugating a polypeptide or peptide to an immunogenic carrier protein are well known in the art and include, for example, glutaraldehyde, m-maleimidobenzoyl-N-hydroxysuccinimide ester, carbodiimide and bis-biazotized benzidine.
It may be desirable to coadminister biologic response modifiers (BRM), which have been shown to upregulate T cell immunity or downregulate suppressor cell activity. Such BRMs include, but are not limited to, cimetidine (CIM; 1200 mg/d) (Smith/Kline, PA); low-dose cyclophosphamide (CYP; 300 mg/m.sup.2) (Johnson/Mead, NJ), or a gene encoding a protein involved in one or more immune helper functions, such as B-7.
Immunization protocols have used adjuvants to stimulate responses for many years, and as such adjuvants are well known to one of ordinary skill in the art. Some adjuvants affect the way in which antigens are presented. For example, the immune response is increased when protein antigens are precipitated by alum. Emulsification of antigens also prolongs the duration of antigen presentation.
In one aspect, an adjuvant effect is achieved by use of an agent, such as alum, used in about 0.05 to about 0.1% solution in phosphate buffered saline. Alternatively, the antigen is made as an admixture with synthetic polymers of sugars (Carbopol) used as an about 0.25% solution. Adjuvant effect may also be made my aggregation of the antigen in the vaccine by heat treatment with temperatures ranging between about 70 degrees to about 101° C. for a 30-second to 2-minute period, respectively. Aggregation by reactivating with pepsin treated (Fab) antibodies to albumin, mixture with bacterial cell(s) such as C. parvum, an endotoxin or a lipopolysaccharide component of Gram-negative bacteria, emulsion in physiologically acceptable oil vehicles, such as mannide mono-oleate (Aracel A), or emulsion with a 20% solution of a perfluorocarbon (Fluosol-DA.RTM.) used as a block substitute, also may be employed.
Some adjuvants, for example, certain organic molecules obtained from bacteria, act on the host rather than on the antigen. An example is muramyl dipeptide (N-acetylmuramyl-L-alanyl-D-isoglutamine [MDP]), a bacterial peptidoglycan. The effects of MDP, as with most adjuvants, are not fully understood. MDP stimulates macrophages but also appears to stimulate B cells directly. The effects of adjuvants, therefore, are not antigen-specific. If they are administered together with a purified antigen, however, they can be used to selectively promote the response to the antigen.
Adjuvants have been used experimentally to promote a generalized increase in immunity against unknown antigens (e.g., U.S. Pat. No. 4,877,611). In certain embodiments, hemocyanins and hemoerythrins may also be used in the invention. The use of hemocyanin from keyhole limpet (KLH) is preferred in certain embodiments, although other molluscan and arthropod hemocyanins and hemoerythrins may be employed.
Various polysaccharide adjuvants may also be used. For example, the use of various pneumococcal polysaccharide adjuvants on the antibody responses of mice has been described (Yin et al., 1989). The doses that produce optimal responses, or that otherwise do not produce suppression, should be employed as indicated (Yin et al., 1989). Polyamine varieties of polysaccharides are particularly preferred, such as chitin and chitosan, including deacetylated chitin.
Another group of adjuvants are the muramyl dipeptide (MDP, N-acetylmuramyl-L-alanyl-D-isoglutamine) group of bacterial peptidoglycans. Derivatives of muramyl dipeptide, such as the amino acid derivative threonyl-MDP, and the fatty acid derivative MTPPE, are also contemplated.
U.S. Pat. No. 4,950,645 describes a lipophilic disaccharide-tripeptide derivative of muramyl dipeptide which is described for use in artificial liposomes formed from phosphatidyl choline and phosphatidyl glycerol. It is the to be effective in activating human monocytes and destroying tumor cells, but is non-toxic in generally high doses. The compounds of U.S. Pat. No. 4,950,645 and PCT Patent Application WO 91/16347, are contemplated for use with cellular carriers and other embodiments of the present invention.
Another adjuvant contemplated for use in the present invention is BCG. BCG (bacillus Calmette-Guerin, an attenuated strain of Mycobacterium) and BCG-cell wall skeleton (CWS) may also be used as adjuvants in the invention, with or without trehalose dimycolate. Trehalose dimycolate may be used itself. Trehalose dimycolate administration has been shown to correlate with augmented resistance to influenza virus infection in mice (Azuma et al., 1988). Trehalose dimycolate may be prepared as described in U.S. Pat. No. 4,579,945.
BCG is an important clinical tool because of its immunostimulatory properties. BCG acts to stimulate the reticulo-endothelial system, activates natural killer cells and increases proliferation of hematopoietic stem cells. Cell wall extracts of BCG have proven to have excellent immune adjuvant activity. Molecular genetic tools and methods for mycobacteria have provided the means to introduce foreign genes into BCG (Jacobs et al., 1987; Snapper et al., 1988; Husson et al., 1990; Martin et al., 1990).
Live BCG is an effective and safe vaccine used worldwide to prevent tuberculosis. BCG and other mycobacteria are highly effective adjuvants, and the immune response to mycobacteria has been studied extensively. With nearly 2 billion immunizations, BCG has a long record of safe use in man (Luelmo, 1982; Lotte et al.., 1984). It is one of the few vaccines that can be given at birth, it engenders long-lived immune responses with only a single dose, and there is a worldwide distribution network with experience in BCG vaccination. An exemplary BCG vaccine is sold as TICE BCG (Organon Inc., West Orange, N.J.).
Amphipathic and surface active agents, e.g., saponin and derivatives such as QS21 (Cambridge Biotech), form yet another group of adjuvants for use with the immunogens of the present invention. Nonionic block copolymer surfactants (Rabinovich et al., 1994; Hunter et al., 1991) may also be employed. Oligonucleotides are another useful group of adjuvants (Yamamoto et al., 1988). Quil A and lentinen are other adjuvants that may be used in certain embodiments of the present invention.
In some embodiments, detoxified endotoxins can be used as adjuvants, such as the refined detoxified endotoxin of U.S. Pat. No. 4,866,034. These refined detoxified endotoxins are effective in producing adjuvant responses in mammals. Of course, the detoxified endotoxins may be combined with other adjuvants to prepare multi-adjuvant-incorporated cells. For example, combination of detoxified endotoxins with trehalose dimycolate is particularly contemplated, as described in U.S. Pat. No. 4,435,386. Combinations of detoxified endotoxins with trehalose dimycolate and endotoxic glycolipids is also contemplated (U.S. Pat. No. 4,505,899), as is combination of detoxified endotoxins with cell wall skeleton (CWS) or CWS and trehalose dimycolate, as described in U.S. Pat. Nos. 4,436,727, 4,436,728 and 4,505,900. Combinations of just CWS and trehalose dimycolate, without detoxified endotoxins, is also envisioned to be useful, as described in U.S. Pat. No. 4,520,019.
In other embodiments, the present invention contemplates that a variety of adjuvants may be employed in the membranes of cells, resulting in an improved immunogenic composition. The only requirement is, generally, that the adjuvant be capable of incorporation into, physical association with, or conjugation to, the cell membrane of the cell in question. Those of skill in the art will know the different kinds of adjuvants that can be conjugated to cellular vaccines in accordance with this invention and these include alkyl lysophosphilipids (ALP); BCG; and biotin (including biotinylated derivatives) among others. Certain adjuvants particularly contemplated for use are the teichoic acids from Gram-cells. These include the lipoteichoic acids (LTA), ribitol teichoic acids (RTA) and glycerol teichoic acid (GTA). Active forms of their synthetic counterparts may also be employed in connection with the invention (Takada et al., 1995a).
Various adjuvants, even those that are not commonly used in humans, may still be employed in animals, where, for example, one desires to raise antibodies or to subsequently obtain activated T cells. The toxicity or other adverse effects that may result from either the adjuvant or the cells, e.g., as may occur using non-irradiated tumor cells, is irrelevant in such circumstances.
One group of adjuvants preferred for use in some embodiments of the present invention are those that can be encoded by a nucleic acid (e.g., DNA or RNA). It is contemplated that such adjuvants may be encoded in a nucleic acid (e.g., an expression vector) encoding the antigen, or in a separate vector or other construct. These nucleic acids encoding the adjuvants can be delivered directly, such as for example with lipids or liposomes.
An antigenic composition of the present invention may be mixed with one or more additional components (e.g., excipients, salts, etc.) which are pharmaceutically acceptable and compatible with at least one active ingredient (e.g., antigen). Suitable excipients are, for example, water, saline, dextrose, glycerol, ethanol and combinations thereof.
An antigenic composition of the present invention may be formulated into the vaccine as a neutral or salt form. A pharmaceutically-acceptable salt, includes the acid addition salts (formed with the free amino groups of the peptide) and those which are formed with inorganic acids such as, for example, hydrochloric or phosphoric acid, or such organic acids as acetic, oxalic, tartaric, mandelic, and the like. A salt formed with a free carboxyl group also may be derived from an inorganic base such as, for example, sodium, potassium, ammonium, calcium, or ferric hydroxide, and such organic bases as isopropylamine, trimethylamine, 2-ethylamino ethanol, histidine, procaine, and combinations thereof.
In addition, if desired, an antigenic composition may comprise minor amounts of one or more auxiliary substances such as for example wetting or emulsifying agents, pH buffering agents, etc. which enhance the effectiveness of the antigenic composition or vaccine.
Once produced, synthesized and/or purified, an antigen or other vaccine component may be prepared as a vaccine or immunogenic composition for administration to an individual. The preparation of a vaccine is generally well understood in the art, as exemplified by U.S. Pat. Nos. 4,608,251, 4,601,903, 4,599,231, 4,599,230, and 4,596,792, all incorporated herein by reference. Such methods may be used to prepare a vaccine comprising an antigenic composition comprising a particular cancer antigen as active ingredient(s), in light of the present disclosure. In particular embodiments, the compositions of the present invention are prepared to be pharmacologically acceptable vaccines.
In some embodiments, pharmaceutical vaccine or immunogenic compositions of the present invention comprise an effective amount of one or more cancer antigens dissolved or dispersed in a pharmaceutically acceptable carrier. The phrases “pharmaceutical or pharmacologically acceptable” refers to molecular entities and compositions that do not produce an adverse, allergic or other untoward reaction when administered to an animal, such as, for example, a human, as appropriate. The preparation of a pharmaceutical composition that contains at least one cancer antigen will be known to those of skill in the art in light of the present disclosure, as exemplified by Remington’s Pharmaceutical Sciences, 18th Ed. Mack Printing Company, 1990, incorporated herein by reference. Moreover, for animal (e.g., human) administration, it will be understood that preparations should meet sterility, pyrogenicity, general safety and purity standards as required by FDA Office of Biological Standards.
As used herein, “pharmaceutically acceptable carrier” includes any and all solvents, dispersion media, coatings, surfactants, antioxidants, preservatives (e.g., antibacterial agents, antifungal agents), isotonic agents, absorption delaying agents, salts, preservatives, drugs, drug stabilizers, binders, excipients, disintegration agents, lubricants, sweetening agents, flavoring agents, dyes, such like materials and combinations thereof, as would be known to one of ordinary skill in the art (see, for example, Remington’s Pharmaceutical Sciences, 18th Ed. Mack Printing Company, 1990, pp. 1289-1329, incorporated herein by reference). In some embodiments, the antigen may comprise different types of carriers depending on whether it is to be administered in solid, liquid or aerosol form, and whether it need to be sterile for such routes of administration as injection. Except insofar as any conventional carrier is incompatible with the active ingredient, its use in the therapeutic or pharmaceutical compositions is contemplated.
In any case, the composition may comprise various antioxidants to retard oxidation of one or more component. Additionally, the prevention of the action of microorganisms can be brought about by preservatives such as various antibacterial and antifungal agents, including but not limited to parabens (e.g., methylparabens, propylparabens), chlorobutanol, phenol, sorbic acid, thimerosal or combinations thereof.
In some embodiments, the antigen may be formulated into a composition in a free base, neutral or salt form. Pharmaceutically acceptable salts, include the acid addition salts, e.g., those formed with the free amino groups of a proteinaceous composition, or which are formed with inorganic acids such as for example, hydrochloric or phosphoric acids, or such organic acids as acetic, oxalic, tartaric or mandelic acid. Salts formed with the free carboxyl groups can also be derived from inorganic bases such as for example, sodium, potassium, ammonium, calcium or ferric hydroxides; or such organic bases as isopropylamine, trimethylamine, histidine or procaine.
In embodiments where the composition is in a liquid form, a carrier can be a solvent or dispersion medium comprising but not limited to, water, ethanol, polyol (e.g., glycerol, propylene glycol, liquid polyethylene glycol, etc), lipids (e.g., triglycerides, vegetable oils, liposomes) and combinations thereof. The proper fluidity can be maintained, for example, by the use of a coating, such as lecithin; by the maintenance of the required particle size by dispersion in carriers such as, for example liquid polyol or lipids; by the use of surfactants such as, for example hydroxypropylcellulose; or combinations thereof such methods. In many cases, it will be preferable to include isotonic agents, such as, for example, sugars, sodium chloride or combinations thereof.
In some embodiments, sterile injectable solutions can be prepared by incorporating the antigens in the required amount in the appropriate solvent with various of the other ingredients enumerated above, as required, followed by filtered sterilization. Generally, dispersions are prepared by incorporating the various sterilized active ingredients into a sterile vehicle which contains the basic dispersion medium and/or the other ingredients. In the case of sterile powders for the preparation of sterile injectable solutions, suspensions or emulsion, the preferred methods of preparation are vacuum-drying or freeze-drying techniques which yield a powder of the active ingredient plus any additional desired ingredient from a previously sterile-filtered liquid medium thereof. The liquid medium should be suitably buffered if necessary and the liquid diluent first rendered isotonic prior to injection with sufficient saline or glucose.
The composition must be stable under the conditions of manufacture and storage, and preserved against the contaminating action of microorganisms, such as bacteria and fungi. It will be appreciated that endotoxin contamination should be kept minimally at a safe level, for example, less than 0.5 ng/mg protein.
In particular embodiments, prolonged absorption of an injectable composition can be brought about by the use in the compositions of agents delaying absorption, such as, for example, aluminum monostearate, gelatin or combinations thereof.
For a broad overview of controlled delivery systems, see, Banga, A. J., Therapeutic Peptides and Proteins: Formulation, Processing, and Delivery Systems, Technomic Publishing Company, Inc., Lancaster, Pa., (1995). Particulate systems include microspheres, microparticles, microcapsules, nanocapsules, nanospheres, and nanoparticles. Microcapsules can contain the therapeutically active agents as a central core. In microspheres the therapeutic can be dispersed throughout the particle. Particles, microspheres, and microcapsules smaller than about 1 µm are generally referred to as nanoparticles, nanospheres, and nanocapsules, respectively. Microparticles are typically around 100 µm in diameter. See, for example, Kreuter, J., Colloidal Drug Delivery Systems, J. Kreuter, ed., Marcel Dekker, Inc., New York, N.Y., pp. 219-342 (1994); and Tice & Tabibi, Treatise on Controlled Drug Delivery, A. Kydonieus, ed., Marcel Dekker, Inc. New York, N.Y., pp. 315-339, (1992).
In some embodiments, polymers can be used for controlled release of compositions disclosed herein. Various degradable and nondegradable polymeric matrices for use in controlled drug delivery are known in the art (Langer, Accounts Chem. Res. 26:537-542, 1993). For example, the block copolymer, polaxamer 407, exists as a viscous yet mobile liquid at low temperatures but forms a semisolid gel at body temperature. It has been shown to be an effective vehicle for formulation and sustained delivery of recombinant interleukin-2 and urease (Johnston et al., Pharm. Res. 9:425-434, 1992; and Pec et al., J. Parent. Sci. Tech. 44(2):58-65, 1990). In yet another aspect, liposomes can be used for controlled release as well as drug targeting of the lipid-capsulated drug (Betageri et al., Liposome Drug Delivery Systems, Technomic Publishing Co., Inc., Lancaster, Pa. (1993)).
A vaccination or immunizing composition delivery schedule and dosages may be varied on a patient by patient basis, taking into account, for example, factors such as the weight and age of the patient, the type of disease being treated, the severity of the disease condition, previous or concurrent therapeutic interventions, the manner of administration and the like, which can be readily determined by one of ordinary skill in the art.
A vaccine or immunizing composition may be administered in a manner compatible with the dosage formulation, and in such amount as will be therapeutically effective and immunogenic. For example, the intramuscular route may be preferred in the case of toxins with short half lives in vivo. The quantity to be administered depends on the subject to be treated, including, e.g., the capacity of the individual’s immune system to synthesize antibodies, and the degree of protection desired. The dosage of the vaccine will depend on the route of administration and will vary according to the size of the host. Precise amounts of an active ingredient required to be administered depend on the judgment of the practitioner. In certain embodiments, pharmaceutical compositions may comprise, for example, at least about 0.1% of an active compound. In other embodiments, the active compound may comprise between about 2% to about 75% of the weight of the unit, or between about 25% to about 60%, for example, and any range derivable therein. However, a suitable dosage range may be, for example, of the order of several hundred micrograms active ingredient per vaccination. Proper dosages of the polypeptides, nucleic acids, viral vectors, or cells can be determined without undue experimentation using standard dose-response protocols. In other non-limiting examples, a dose may also comprise from about 1 microgram/kg/body weight, about 5 microgram/kg/body weight, about 10 microgram/kg/body weight, about 50 microgram/kg/body weight, about 100 microgram/kg/body weight, about 200 microgram/kg/body weight, about 350 microgram/kg/body weight, about 500 microgram/kg/body weight, about 1 milligram/kg/body weight, about 5 milligram/kg/body weight, about 10 milligram/kg/body weight, about 50 milligram/kg/body weight, about 100 milligram/kg/body weight, about 200 milligram/kg/body weight, about 350 milligram/kg/body weight, about 500 milligram/kg/body weight, to about 1000 mg/kg/body weight or more per vaccination, and any range derivable therein. In non-limiting examples of a derivable range from the numbers listed herein, a range of about 5 mg/kg/body weight to about 100 mg/kg/body weight, about 5 microgram/kg/body weight to about 500 milligram/kg/body weight, etc., can be administered, based on the numbers described above. A suitable regime for initial administration and booster administrations (e.g., innoculations) are also variable, but are typified by an initial administration followed by subsequent inoculation(s) or other administration(s).
In many instances, it will be desirable to have multiple administrations of the vaccine or immunizing composition, usually not exceeding six vaccinations, for example, more usually not exceeding four vaccinations and in some cases one or more, usually at least about three vaccinations. The vaccinations may be at from two to twelve-week intervals, more usually from three to five week intervals, although longer intervals are encompassed herein. Periodic boosters at intervals of 1-5 years, usually three years, may be desirable to maintain protective levels of the antibodies.
The course of the immunization may be followed by assays for antibodies for the supernatant antigens. The assays may be performed by labeling with conventional labels, such as radionuclides, enzymes, fluorescents, and the like. These techniques are well known and may be found in a wide variety of patents, such as U.S. Pat. Nos. 3,791,932; 4,174,384 and 3,949,064, as illustrative of these types of assays.
Any of the compositions and devices described herein may be comprised in a kit. In a non-limiting example, a cancer antigen composition may be comprised in a kit along with the microneedle delivery device. The immunizing components of the kit may be packaged either in aqueous media or in lyophilized form. The kits of the present invention also will typically include a means for containing the composition and any other reagent containers in close confinement for commercial sale. Such containers may include injection or blow-molded plastic containers into which the desired vials are retained.
The component(s) of the kit may be provided as dried powder(s). When reagents and/or components are provided as a dry powder, the powder can be reconstituted by the addition of a suitable solvent. It is envisioned that the solvent may also be provided in another container means. The kits may comprise a container means for containing a sterile, pharmaceutically acceptable buffer and/or other diluent.
As provided herein, the immunizing composition is administered using a microneedle delivery device. In some embodiments, the microneedle delivery device useful in the methods of the invention is depicted in
In some embodiments, the microneedle delivery device comprises
In some embodiments, the means to encourage flow of the composition contained in the reservoir into the skin is selected from the group consisting of a plunger, pump and suction mechanism. In some embodiments, the means to encourage flow of the composition contained in the reservoir into the skin is a mechanical spring loaded pump system.
In some embodiments, the microneedles have a single groove inset along the outer wall of the microneedle, wherein the single groove has a screw thread shape going clockwise or counterclockwise around the microneedle.
In some embodiments, the microneedles are from 0.1 mm to about 2.5 mm in length and from 0.01 mm to about 0.05 mm in diameter.
In some embodiments, the microneedles are made from a substance comprising gold.
In some embodiments, the plurality of microneedles comprises an array of microneedles in the shape of a circle.
In some embodiments, the microneedles are made of 24-carat gold plated stainless steel and comprise an array of about 10 to about 50 microneedles. In some embodiments, the array comprises 20 microneedles.
In some embodiments, the microneedle delivery device is repeatedly pressed against the subject’s skin to deliver the composition to the area of the skin to be treated. In some embodiments, the microneedle delivery device is repeatedly pressed about 10, about 20, about 30, about 40, about 50, about 100, about 200, about 300, about 400, about 500, about 600, about 700, about 800, about 900, about 1000, about 1100, about 1200, about 1300, about 1400, about 1500, about 1600, about 1700, about 1800, about 1900, or about 2000 or more times to administer the composition.
In some embodiments, the immunizing composition is administered by the microneedle delivery device with a repeated motion of penetrating the microneedle delivery device into the skin of the subject. In some embodiments, the composition is delivered into the skin by passing through the one or multiple grooves along the outer wall of the microneedle. In some embodiments, the microneedles are non-hollow.
In some embodiments, the administering comprises a repeated motion of penetrating the microneedle delivery device into the subject’s skin in different areas of the subject’s body.
In some embodiments, the subject’s skin in the head, limbs and/or torso regions are repeatedly penetrated by the microneedle delivery device. In some embodiments, the subject’s skin is penetrated in regions that are in proximity to one or more lymph nodes.
For example, repeated penetrations can be made in the subject’s arms, legs, and torso in order to deliver the immunizing composition to different areas of the subject’s body, in order to enhance the subject’s immune response.
In some embodiments, the microneedle delivery device comprises a single or an array of microneedles. In some embodiments, the microneedles will have one or multiple grooves inset along its outer wall. This structural feature of the dermal delivery device allows liquids stored in a reservoir at the base of each needle to travel along the needle shaft into the tissue.
In some embodiments, the microneedle array comprises from about 1 to about 500 microneedles, which will be anywhere from about 0.1 to about 2.5 mm in length and from 0.01 to about 0.5 mm in diameter, and be composed of any metal, metal alloy, metalloid, polymer, or combination thereof, such as gold, steel, silicon, PVP (polyvinylpyrrlidone), etc. The microneedles will each have one or more recesses running a certain depth into the outer wall to allow for flow of the substance to be delivered down the microneedle and into the dermis; these recesses can be in a plurality of shapes, including but not limited to: straight line, cross shape (+), flat shape (-), or screw thread shape going clockwise or counterclockwise. The array will be in any shape or combination of shapes, continuous, or discontinuous. The list of possible shapes includes, but is not limited to, circles, triangles, rectangles, squares, rhomboids, trapezoids, and any other regular or irregular polygons. The array can be attached to a reservoir to hold the substances to be delivered, and this reservoir will be any volume (0.25 mL to 5 mL), shape, color, or material (glass, metal, alloy, or polymer), as determined necessary. This reservoir will itself be attached to or contain a means to encourage flow of the drug solutions contained in the reservoir into the skin. Two non-limiting examples of such means are 1) a plate and spring that allows the contained solutions to flow only when the device is tapped into the skin, and 2) a syringe that contains the drug solutions to be delivered and includes a plunger that can be depressed to mechanically drive the solution into the skin.
The microneedle delivery device is capable of delivering compositions directly to the epidermal, dermal and subcuticular layers of the skin. Therefore, it should be understood that further embodiments developed for use with non-hollow or hollow microneedle systems of delivery by those skilled in the art fall within the spirit and scope of this disclosure.
In another aspect, a microneedle device for use in the methods described herein is a device such as described in U.S. Pat. No. 8,257,324, which is hereby incorporated by reference. Briefly, the devices include a substrate to which a plurality of hollow microneedles are attached or integrated, and at least one reservoir, containing a bioactive formulation, selectably in communication with the microneedles, wherein the volume or amount of composition to be delivered can be selectively altered. The reservoir can be, for example, formed of a deformable, preferably elastic, material. The device typically includes a means, such as a plunger, for compressing the reservoir to drive the bioactive formulation from the reservoir through the microneedles, A reservoir, can be, for example, a syringe or pump connected to the substrate. A device, in some instances, comprises: a plurality of hollow microneedles (each having a base end and a tip), with at least one hollow pathway disposed at or between the base end and the tip, wherein the microneedles comprise a metal; a substrate to which the base ends of the microneedles are attached or integrated; at least one reservoir in which the material is disposed and which is in connection with the base end of at least one of the microneedles, either integrally or separably; a sealing mechanism interposed between the at least one reservoir and the substrate, wherein the sealing mechanism comprises a fracturable barrier; and a device that expels the material in the reservoir into the base end of at least one of the microneedles and into the skin. The reservoir comprises a syringe secured to the substrate, and the device that expels the material comprises a plunger connected to a top surface of the reservoir. The substrate may be adapted to removably connect to a standard or Luer-lock syringe. In one instance, the device may further include a spring engaged with the plunger. In another instance, the device may further include an attachment mechanism that secures the syringe to the device. In another instance, the device may further include a sealing mechanism that is secured to the tips of the microneedles. In another instance, the device may further include means for providing feedback to indicate that delivery of the material from the reservoir has been initiated or completed. An osmotic pump may be included to expel the material from the reservoir. One or more microneedles may be disposed at an angle other than perpendicular to the substrate. In certain instances, the at least one reservoir comprises multiple reservoirs that can be connected to or are in communication with each other. The multiple reservoirs may comprise a first reservoir and a second reservoir, wherein the first reservoir contains a solid formulation and the second reservoir contains a liquid carrier for the solid formulation. A fracturable barrier for use in the devices can be, for example, a thin foil, a polymer, a laminate film, or a biodegradable polymer. The device may further comprise, in some instances, means for providing feedback to indicate that the microneedles have penetrated the skin.
In some embodiments, the device can include, in some instances, a single or plurality of solid, screw-type microneedles, of single or varied length. Typically the needles attach to a substrate or are embedded within the substrate. The substrate can be made of any metal, metal alloy, ceramics, organics metalloid, polymer, or combination thereof, including composites, such as gold, steel, silicon, PVP (polyvinylpyrrlidone) etc. The screw-shape dimensions may be variable. For example, in one embodiment the screw-shape may be a tight coiled screw shape, whereas in another embodiment the screw-shape might be a loose coiled screw shape whereby the screw threads in one embodiment lie closely together along the outer edge of the needle and, in another embodiment, the screw threads lie far from each other along the outer edge of the needle.
In one embodiment a reservoir would attach to the substrate to allow drug solution to flow down the side of the microneedles. In one embodiment the reservoir is a solid canister of differing sizes depending on the desired volume or amount of drug to be delivered. The reservoir contains the drug to be delivered. In another embodiment, the reservoir can be supported by a mechanical (spring loaded or electrified machine-driven) pump system to deliver the drug solution. In another embodiment, the reservoir is composed of a rubber, elastic, or otherwise deformable and flexible material to allow manual squeezing to deliver the drug solution. In another embodiment the device includes hollow needles or needles with alternative ridges and shapes to more efficiently drive solution from the reservoir through to the dermis.
A device described herein may contain, in certain instances, about twenty screw thread design surgical grade microneedles. Each microneedle has a diameter that is thinner than a human hair and may be used for direct dermal application. In one instance, a microneedle has a diameter of less than about 0.18 mm. In another instance, a microneedle has a diameter of about 0.15 mm, about 0.14 mm, about 0.13 mm, about 0.12 mm, about 0.11 mm, or about 0.10 mm. Each microneedle may be plated with 24 carat gold. The device allows for targeted and uniform delivery of a composition comprising the immunizing composition into the skin in a process that is painless compared to injectables. Administration can result in easy and precise delivery of a composition comprising the immunizing composition with generally no bruising, pain, swelling and bleeding caused by the injection.
The device may include means, manual or mechanical, for compressing the reservoir, creating a vacuum, or otherwise using gravity or pressure to drive the immunizing composition from the reservoir through the microneedles or down along the sides of the microneedle. The means can include a plunger, pump or suction mechanism. In another embodiment, the reservoir further includes a means for controlling rate and precise quantity of drug delivered by utilizing a semi-permeable membrane, to regulate the rate or extent of drug which flows along the shaft of the microneedles. The microneedle device enhances transportation of drugs across or into the tissue at a useful rate. For example, the microneedle device must be capable of delivering drug at a rate sufficient to be therapeutically useful. The rate of delivery of the drug composition can be controlled by altering one or more of several design variables. For example, the amount of material flowing through the needles can be controlled by manipulating the effective hydrodynamic conductivity (the volumetric through-capacity) of a single device array, for example, by using more or fewer microneedles, by increasing or decreasing the number or diameter of the bores in the microneedles, or by filling at least some of the microneedle bores with a diffusion-limiting material. It can be preferred, however, to simplify the manufacturing process by limiting the needle design to two or three “sizes” of microneedle arrays to accommodate, for example small, medium, and large volumetric flows, for which the delivery rate is controlled by other means.
Other means for controlling the rate of delivery include varying the driving force applied to the drug composition in the reservoir. For example, in passive diffusion systems, the concentration of drug in the reservoir can be increased to increase the rate of mass transfer. In active systems, for example, the pressure applied to the reservoir can be varied, such as by varying the spring constant or number of springs or elastic bands. In either active or passive systems, the barrier material can be selected to provide a particular rate of diffusion for the drug molecules being delivered through the barrier at the needle inlet.
The array may be in any shape or combination of shapes, continuous, or discontinuous. The list of possible shapes includes, but is not limited to, circles, triangles, rectangles, squares, rhomboids, trapezoids, and any other regular or irregular polygons.
The array may be attached to a reservoir to hold the substances to be delivered, and this reservoir may be any volume (about 0.25 mL to about 5 mL), shape, color, or material (glass, metal, alloy, or polymer), as determined necessary.
This reservoir can itself be attached to or contain a means to encourage flow of the drug solutions contained in the reservoir into the skin. Two non-limiting examples of such means are 1) a plate and spring that allows the contained solutions to flow only when the device is tapped into the skin, and 2) a syringe that contains the drug solutions to be delivered and includes a plunger that can be depressed to mechanically drive the solution into the skin.
In some embodiments, the device can include a single or plurality of solid, screw-type microneedles, of single or varied lengths housed in a plastic or polymer composite head which embodies a corrugated rubber connector. In some embodiments, the needles attach to a substrate or are embedded within the substrate. The substrate can be made of any metal, metal alloy, ceramics, organics metalloid, polymer, or combination thereof, including composites, such as gold, steel, silicon, PVP (polyvinylpyrrlidone) etc. The screw-shape dimensions may be variable. For example, in one embodiment the screw-shape may be a tight coiled screw shape, whereas in another embodiment the screw-shape might be a loose coiled screw shape. The corrugated rubber connector is a unique advantage conferring feature which bestows the microneedle head with a universally adoptable feature for interfacing the micro needle cartridges with multiple glass and or plastic vials, reservoirs and containers as well as electronic appendages for an altogether enhanced adjunct liquid handling, security and surveillance utility.
In one embodiment a reservoir would attach to the substrate to allow drug solution to flow down the side of the microneedles. In one embodiment the reservoir is a solid canister of differing sizes depending on the desired volume or amount of drug to be delivered. The reservoir contains the drug to be delivered. In another embodiment, the reservoir can be supported by a mechanical (spring loaded or electrified machine-driven) pump system to deliver the drug solution. In another embodiment, the reservoir is composed of a rubber, elastic, or otherwise deformable and flexible material to allow manual squeezing to deliver the drug solution. In another embodiment the device includes hollow needles or needles with alternative ridges and shapes to more efficiently drive solution from the reservoir through to the dermis.
While the present teachings are described in conjunction with various embodiments, it is not intended that the present teachings be limited to such embodiments. On the contrary, the present teachings encompass various alternatives, modifications, and equivalents, as will be appreciated by those of skill in the art.
Throughout this disclosure, various publications, patents and published patent specifications are referenced by an identifying citation. The disclosures of these publications, patents and published patent specifications are hereby incorporated by reference into the present disclosure to more fully describe the state of the art to which this invention pertains.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2021/024475 | 3/26/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63000409 | Mar 2020 | US |
