Patent Application
20080038294
The present invention relates, for example, to compositions for inactivated influenza vaccines and routes of administration wherein a single intranasal or inhalational administration yields a systemic immune response that is positively correlated to clinical protection.
Various concepts for immunization against influenza via the nasal or oropharyngeal route and using inactivated influenza antigen have been explored as needle-less alternatives to the subcutaneous or intramuscular immunization. Experimental data supportive for needle-less approaches have been generated in animal models. Concepts using inactivated influenza antigen (such as chemically inactivated whole virus particles, or further processed viral components such as split virus, or purified surface antigens haemagglutinin (HA) and/or neuraminidase (NA)) for immunization via the intranasal route that are supported by animal data include either the use of an adjuvant or immune stimulator in combination with the inactivated influenza antigen, or require multiple vaccination. An adjuvant is any substance that enhances the immunogenicity of antigens mixed with it. In humans successful vaccination against influenza via the intranasal route has only been reported for (a) live (cold adapted strains) influenza vaccines (FluMist™, MedImmune Vaccines Inc) (Refs 1, 2, 3), (b) virosomal influenza vaccine adjuvanted with the heat labile toxin of E. coli (NasalFlu, Berna Biotech Ltd) (Ref 4) or (c) using high amounts of antigen and repeated vaccination (Refs 5, 10, 11). Although live vaccines are capable of inducing a satisfactory immune response, their specific nature of being a live virus causes additional safety concerns, and is likely to induce side effects due to the required viral replication round in the upper respiratory tract. Also the required storage conditions are limiting the commercialization of these products. A strong association between the use of the intranasal influenza vaccine with E. coli HLT as adjuvant, and facial paralysis (Bell's Palsy), led to withdrawal of the HLT adjuvanted virosomal vaccine from the market for the. (Ref 6).
The efficacy of influenza vaccines in a given population may be estimated by assessing immunogenicity parameters relating to the amount of anti-influenza antibodies that are generated after vaccination. These immunogenicity parameters, generally referred to as CHMP criteria, are used for the annual re-licensing of inactivated influenza vaccines. (Ref 7). To date, successful immunization of humans against influenza, meeting these immunology requirements or CHMP criteria (Ref 7), with one single intranasal administration of an inactivated vaccine, and without the addition of an adjuvant, being an additional ingredient of the vaccine that is not derived from the infective agent that the vaccine is intended to prevent for and that is added to the vaccine formulation for the purpose of enhancing the immune response to the antigen, has not been described. It is therefore recognized that there is still a need in the art for an inactivated influenza vaccine composition that is capable of inducing a satisfactory systemic immune response after a single intranasal administration, does not contain an adjuvant, and meets the CHMP criteria (Ref 7) with said single administration.
Said ‘CHMP criteria’ are defined as follows. In the CHMP (Committee for Medicinal Products for Human Use) Note for Guidance on Harmonisation of Requirements for Influenza Vaccines, the following serological parameters are defined to assess the immunogenicity of inactivated influenza vaccines:
The CHMP requirement for influenza vaccine immunogenicity is that for each of the three virus strains in the vaccine at least one of the following criteria is met:
The invention also applies to children, for whom it was shown that they respond immunologically in a comparable manner to adults (Ref 8). The invention also applies to elderly individuals.
Surprisingly, and in contradiction with pre-clinical rodent data and literature on human clinical experience, the invention provides a method of inducing an immune response in humans after a single intranasal vaccination with an inactivated influenza vaccine comprising reconstituted influenza envelopes was in accordance with all three CHMP criteria for influenza vaccine efficacy for the age group of 18-60 years old. One single intranasal administration is an inoculation of the vaccine formulation via one or both nostrils without the need for a repetition of the administration of the vaccine formulation in order to meet the above-mentioned CHMP criteria for immunogenicity of an inactivated influenza vaccine. One single administration of a vaccine (via the nasal, inhalation, oral, subcutaneous or intramuscular route) in general is a vaccination schedule which does not include multiple administrations of the vaccine that are separated in time by days or weeks known in the art as priming and boosting. A formulation designed as an intranasal or inhalational administration formulation comprises a mixture of one or more active components and excipients prepared in such a way as to allow intranasal or inhalational administration.
The present invention provides a method of inducing an immune response against an influenza virus in a host. In an embodiment the method comprises administering influenza virosomes comprising reconstituted envelopes of the influenza virus to the host. In an embodiment the method of administering is via intranasal or inhalational administration. The present invention also provides a method of inducing a systemic immune response (circulating immunoglobulins or antibody-producing B cells) which is in accordance with the CHMP criteria, advantageously with a single intranasal or inhalational administration of virosomal influenza vaccine. The present invention also provides a method of inducing a local or mucosal immune response, comprising an increase in secretory immunoglobulins known as IgA at the surface of mucosal membranes, advantageously with a single intranasal or inhalational administration of virosomal influenza vaccine. Induction of specific IgG and IgA responses after intranasal administration involves the activity of lymphoid tissue in the nasal cavity (Ref 12). Such tissue is known as nasal-associated lymphoid tissue (NALT), and has been shown also to be a mucosal inductive site for cellular immune responses (Ref 13). Since it is known that virosomes have the potential to induce cellular immune responses (Ref 14, 15) the present invention also provides a method of inducing specific cytotoxic lymphocytes (CTL), and thus a cytotoxic lymphocyte-mediated immune response.
The present invention also provides a method of preventing an influenza viral infection in a host. In an embodiment the method comprises administering influenza virosomes comprising reconstituted envelopes of the influenza virus to the host. In one embodiment the method of administering is via intranasal or inhalational administration.
The term “prevent,” “preventing” and “prevention” refers to administration of a composition disclosed herein to a host on a prophylactic or preventative basis, to reduce the probability that the host will develop an influenza viral infection over a period of time following the administration. Such individuals may be identified on the basis of risk factors that are known to correlate with the subsequent occurrence of influenza infection. Alternatively, prevention therapy may be administered without prior identification of a risk factor, as a solely prophylactic measure. Delaying the onset of the at least one symptom may also be considered prevention or prophylaxis. Reduction in the peak severity of at least one symptom over the course of a viral infection may also be considered prevention or prophylaxis.
Virosomes are lipid bilayers containing viral glycoproteins. Virosomes are generally produced by extraction of membrane proteins and lipids from enveloped viruses with a detergent, followed by reconstitution of characteristic bilayers by removal of said detergent. The present invention also provides a composition of influenza virosomes comprising reconstituted influenza viral envelopes (in particular reconstituted without further addition of lipids and without the addition of an immunomodulator of immunostimulant (generally referred to as an adjuvant)) for the use of vaccination via an aerosol which is administrated to the mucosa of the nasopharynx or oropharynx via one or both nostrils to achieve systemic and local immunity against influenza. A single administration via inhalation is possible also. A single oral mucosal administration is possible also.
Reconstituted influenza virosomes may be prepared from inactivated virus, which may be solubilized by a non-dialyzable detergent that is removed by adsorption to hydrophobic beads. The preparation may comprise a purified suspension of one or more influenza antigens selected from haemagglutinin (HA), neuraminidase (NA), a derivative of haemagglutinin, and a derivative of neuraminidase. The viral membrane proteins HA and NA may be reconstituted in a membrane composed of viral lipids, containing low levels of endotoxin and ovalbumin (see Ref 9). Derivatives of haemagglutinin and/or neuraminidase are haemagglutinin and/or neuraminidase molecules with modified amino acid sequences and/or structures. Amino acids may for instance be deleted, altered or added to the sequences. Also the glycosylation patterns may be altered. The derivatives retain the ability to induce an immune response when introduced into a host.
The influenza virus used for preparing the reconstituted virosomes can be grown for instance on embryonated hens' eggs or in cell culture either on adherent cells or on cells in suspension. The virus can be for instance a wild-type or a reassortant or a genetically modified strain. The virus type can for instance be any influenza A or B subtype, including pandemic strains.
The present invention also provides vaccines. The term vaccine is understood as being directed to an immunoactive pharmaceutical preparation. In certain embodiments vaccines may comprise harmless variants or derivatives of pathogenic microorganisms that, for example, stimulate the immune system to mount defenses against the actual pathogen. In certain embodiments the vaccine, for example, induces adaptive immunity when administered to a host. A vaccine may contain a dead or attenuated form of a pathogen or a component of the pathogen, such as an antigenic component of the pathogen. The vaccine preparation may further contain a pharmaceutical carrier, which may be designed for the particular mode by which the vaccine is intended to be administered, such as a pharmaceutical carrier designed for intranasal or inhalational administration. An influenza vaccine may comprise one or more non-denatured influenza antigens, one or more of which is capable of inducing an influenza-specific immune response.
In one aspect, the invention provides a composition comprising influenza virosomes comprising reconstituted envelopes of said virus, and further comprising a pharmaceutical carrier for intranasal or inhalational administration. In an embodiment of the composition the virosomes comprise one or more influenza antigens selected from haemagglutinin, neuraminidase, a derivative of haemagglutinin, and a derivative of neuraminidase. In another embodiment, the viral envelopes are entirely derived from viral particles. In another embodiment, no lipid is added from an external source to the reconstituted virosomes. In another embodiment, no separate adjuvant and/or immune stimulator is added to the composition. In a further embodiment, a single intranasal or inhalational administration of the composition to a subject is capable of inducing a systemic immune response. The single intranasal or inhalational administration may also be capable of inducing a local immune response and/or a cytotoxic lymphocyte-mediated immune response. In another embodiment, the subject receiving the administration is a human being. In another embodiment, the immune response comprises an immune response directed against the influenza antigens haemagglutinin and/or neuraminidase, or derivatives thereof. In another embodiment, the immune response is in accordance with the CHMP criteria for influenza vaccine. In another embodiment, the immune response provides one or more of a seroprotection rate of >70% for adults and/or >60% for elderly, a seroconversion rate of >40% for adults and/or >30% for elderly, and a mean fold increase of >2.5 for adults and/or >2.0 for elderly. In another embodiment, the dose of haemagglutinin per viral strain per intranasal or inhalational administration is equal to or lower than 30 μg. In a further embodiment, the composition is a vaccine formulation
Thus, in an embodiment the present invention provides a composition of influenza virosomes comprising reconstituted envelopes of said virus, wherein the viral envelopes are entirely derived from influenza viral particles, wherein no lipid is added from an external source to the reconstituted virosomes, wherein the virosomes comprise the influenza antigens haemagglutinin and/or neuraminidase or derivatives thereof, wherein no separate adjuvant and/or immune stimulator is added to the composition, and wherein the composition is designed as an intranasal or inhalational administration formulation, which composition is characterized in that a single intranasal or inhalational administration of said formulation to a human being is capable of inducing a systemic and/or local immune response against said influenza antigens, which systemic response is in accordance with the CHMP criteria for influenza vaccine, and wherein the dose of haemagglutinin per viral strain per intranasal or inhalational administration is lower than or equal to 30 μg.
In another aspect, the invention provides a use of influenza virosomes comprising reconstituted envelopes of said virus for the manufacture of a composition for intranasal or inhalational administration. In an embodiment of the use, the influenza virosomes comprise one or more influenza antigens selected from haemagglutinin, neuraminidase, a derivative of haemagglutinin, and a derivative of neuraminidase. In another embodiment, the viral envelopes are entirely derived from influenza viral particles. In another embodiment, no lipid is added from an external source to the influenza virosomes in the composition. In another embodiment, no separate adjuvant and/or immune stimulator is added to the composition. In a further embodiment of the use, a single intranasal or inhalational administration of the composition to a subject is sufficient for the induction of a systemic immune response. In other embodiments, the single intranasal or inhalational administration of the composition also induces a local immune response and/or a cytotoxic lymphocytes response. In another embodiment, subject receiving the administration is a human being. In another embodiment, the composition induces an immune response comprising an immune response directed against the influenza antigens haemagglutinin and/or neuraminidase, or derivatives thereof. In another embodiment, the composition induces an immune response which is in accordance with the CHMP criteria for influenza vaccine. In another embodiment, the immune response provides one or more of a seroprotection rate of >70% for adults and/or >60% for elderly, a seroconversion rate of >40% for adults and/or >30% for elderly, and a mean fold increase of >2.5 for adults and/or >2.0 for elderly. In another embodiment, the administered dose of haemagglutinin per viral strain per intranasal or inhalational administration is equal to or lower than 30 μg. In a further embodiment of the use, the manufactured composition is a vaccine formulation.
Thus, in accordance with another embodiment the present invention provides the use of influenza virosomes comprising reconstituted envelopes of said virus for the manufacture of a composition for intranasal or inhalational administration, wherein the viral envelopes are entirely derived from influenza viral particles, wherein no lipid is added from an external source to the reconstituted virosomes, wherein the virosomes comprise the influenza antigens haemagglutinin and/or neuraminidase or derivatives thereof, and wherein no separate adjuvant and/or immune stimulator is added to the composition, which use of said influenza virosomes for the manufacture of a composition for intranasal or inhalational administration is characterized in that a single intranasal or inhalational administration of the composition to a human being is sufficient for the induction of a systemic and/or local immune response against said influenza antigens, which response is in accordance with the CHMP criteria for influenza vaccine, and wherein the dose of haemagglutinin per viral strain per intranasal or inhalational administration is lower than or equal to 30 μg.
In another aspect, the invention provides a vaccine formulation, comprising a composition of influenza virosomes comprising reconstituted envelopes of said virus, wherein the viral envelopes are entirely derived from influenza viral particles, wherein no lipid is added from an external source to the reconstituted virosomes, wherein the virosomes comprise one or more influenza antigens selected from hemagglutinin, neuraminidase, a derivative of hemagglutinin, and a derivative of neuraminidase, wherein no separate adjuvant and/or immune stimulator is added to the composition, characterized in that the vaccine is designed for a single intranasal or inhalational administration to a human being and wherein the dose of haemagglutinin per viral strain per single intranasal or inhalational administration is lower than or equal to 30 μg. In an embodiment of the vaccine formulation, a single intranasal or inhalational administration of the formulation is capable of inducing an immune response comprising one or more of a systemic immune response, a local immune response, and a cytotoxic lymphocyte-mediated immune response in said human being. In a further embodiment, the invention provides a device for intranasal or inhalational administration, comprising the vaccine formulation and a mechanism for aerosolization of the vaccine. In another embodiment, the device contains a quantity of vaccine formulation for a single intranasal or inhalational administration. In another embodiment, the device is disposable.
Thus, in accordance with another embodiment the present invention provides a vaccine formulation comprising a composition of influenza virosomes comprising reconstituted envelopes of said virus, wherein the viral envelopes are entirely derived from influenza viral particles, wherein no lipid is added from an external source to the reconstituted virosomes, wherein the virosomes comprise the influenza antigens haemagglutinin and/or neuraminidase or derivatives thereof, wherein no separate adjuvant and/or immune stimulator is added to the composition, which vaccine is characterized in that the vaccine is designed for a single intranasal or inhalational administration to a human being and wherein the dose of haemagglutinin per viral strain per single intranasal or inhalational administration is lower than or equal to 30 μg. Advantageously, said single intranasal or inhalational administration of the formulation is capable of inducing a systemic and/or local immune response in said human being. In accordance with the present invention there also is provided a device comprising a quantity of said vaccine formulation for a single intranasal or inhalational administration.
In another aspect, the invention provides a method of inducing an immune response against an influenza virus in a host, comprising intranasal or inhalational administration of influenza virosomes comprising reconstituted envelopes of the influenza virus to the host. In an embodiment of the method, the virosomes comprise one or more influenza antigens selected from hemagglutinin, neuraminidase, a derivative of hemagglutinin, and a derivative of neuraminidase. In another embodiment, the viral envelopes are entirely derived from viral particles. In another embodiment, no lipid is added from an external source to the reconstituted virosomes. In another embodiment, no separate adjuvant and/or immune stimulator is added to the composition. In a further embodiment, a single intranasal or inhalational administration of the composition to a subject is sufficient for the induction of a systemic immune response. In another embodiment, the single intranasal or inhalational administration also induces a local immune response and/or a cytotoxic lymphocyte-mediated immune response. In another embodiment, the subject receiving the administration is a human being. In another embodiment, the immune response comprises an immune response directed against the influenza antigens hemagglutinin and/or neuraminidase. In another embodiment, the immune response is in accordance with the CHMP criteria for influenza vaccine. In another embodiment, the immune response provides one or more of a seroprotection rate of >70% for adults and/or >60% for elderly, a seroconversion rate of >40% for adults and/or >30% for elderly, and a mean fold increase of >2.5 for adults and/or >2.0 for elderly. In another embodiment, the dose of hemagglutinin per viral strain per intranasal or inhalational administration is lower than 30 μg. In a further embodiment, the virosomes are formulated as a vaccine for administration.
In another aspect, the invention provides a method of preventing an influenza viral infection in a host, comprising intranasal or inhalational administration of influenza virosomes comprising reconstituted envelopes of the influenza virus to the host. In an embodiment of the method, the virosomes comprise one or more influenza antigens selected from hemagglutinin, neuraminidase, a derivative of hemagglutinin, and a derivative of neuraminidase. In another embodiment, the viral envelopes are entirely derived from viral particles. In another embodiment, no lipid is added from an external source to the reconstituted virosomes. In another embodiment, no separate adjuvant and/or immune stimulator is added to the composition. In a further embodiment, a single intranasal or inhalational administration of the composition to a subject is sufficient for the induction of a systemic immune response. In another embodiment, the single intranasal or inhalational administration also induces a local immune response and/or a cytotoxic lymphocyte-mediated immune response. In another embodiment, the subject receiving the administration is a human being. In another embodiment, the immune response comprises an immune response directed against the influenza antigens hemagglutinin and/or neuraminidase. In another embodiment, the immune response is in accordance with the CHMP criteria for influenza vaccine. In another embodiment, the immune response provides one or more of a seroprotection rate of >70% for adults and/or >60% for elderly, a seroconversion rate of >40% for adults and/or >30% for elderly, and a mean fold increase of >2.5 for adults and/or >2.0 for elderly. In another embodiment, the dose of hemagglutinin per viral strain per intranasal or inhalational administration is lower than 30 μg. In a further embodiment, the virosomes are formulated as a vaccine for administration.
Literature cited:
Groups of 10 influenza seronegative female Balb/c mice received LPP (lipopeptide)-virosomal vaccine by intranasal administration, at HA/LPP ratios of 1:1.5, 1:0.7, 1:0.4, 1:0 (i.e. no LPP) and with 2 μg HA per dose. In addition, a control group of 10 female mice received 0 μg HA/dose (intranasal administration of vehicle).
Four preparations of LPP-containing virosomes were prepared. Briefly, inactivated influenza virus in a 30-40% sucrose solution was sedimented by centrifugation. The virus was resuspended and solubilized in a buffer containing the detergent octaethylene glycol monododecyl ether (OEG). Subsequently, viral nucleocapsid was removed by ultracentrifugation. The OEG-containing supernatant was split in 4 equal volumes and different amounts of the lipopeptide P3CSK4 in OEG-containing buffer were added (P3CSK4: N-palmitoyl-S-[2,3-bis(palmitoyloxy)-(2RS)-propyl]-[R]-cysteinyl-[S]-seryl-[S]-lysyl-[S]-lysyl-[S]-lysyl-[S]-lysine). The volume was adjusted with OEG-containing buffer. OEG was removed by adsorption to a hydrophobic resin. This resulted in the formation of LPP-containing virosomes, reconstituted viral vesicles containing HA and NA in their membranes and (optionally) LPP in their membranes. After OEG removal the virosomes were filtered through a PVDF membrane with a pore size of 0.22 μm.
The starting material was 20 mg of HA from influenza A/Wyoming/3/2003 X-147 (A/Fujian/411/200 (H3N2)-like strain), containing 252 I.U. endotoxin/100 μg HA. After solubilization 4 batches were prepared as outlined in Table 1.
The vehicle was composed of 5 mM Hepes, 145 mM NaCl, 1 mM EDTA (pH 7.4). For group E (see Table 2) vehicle was filtered through a PVDF membrane with a pore size of 0.22 μm. The 4 batches of virosomes prepared were diluted to a concentration of 200 μg/ml for intranasal and 67 μg/ml for intramuscular immunization, and aliquoted in 1-ml vials (2 per group) as indicated in Table 2. These groups of vaccines were used as outlined in Table 4.
*Vehicle: 5 mM Hepes, 145 mM NaCl, 1 mM EDTA (pH 7.4), filtered through a PVDF membrane with a pore size of 0.22 μm.
Analysis of Formulation
The formulations used for this study were analyzed for several variables as indicated in Table 3.
a Lowry assay, principle: Proteins form a blue colour after treatment with alkaline copper sulphate and Folin-ciocalteu phenol reagent. The protein content is determined from the absorbance
b PhEur: monograph 2053 and section 2.7.1.
c Principle: Each phospholipid contains a single phosphor atom, which can be used for the quantification of the phospholipids. The phospholipids are destructed by perchloric acid
d Ph. Eur. 2.6.14
e The Ovalbumine ELISA is a direct sandwich enzyme immunoassay using immobilized polyclonalanti-ovalbumin antibodies for capture and anti ovalbumine-HRP conjugate as detection system. Conjugate and samples are incubated simultaneously. Non
f According to monograph 0869 and 2053: The purity of the monovalent pooled harvest is examined by polyacrylamide gel electrophoresis. Electrophoresis: according Ph. Eur 2.2.31.
Test System
Test Animals
Seven groups of ten female Balb/c mice (BALB/cAnNCrl) each were used.
At the initiation of treatment, the mice were 8-9 weeks old and weighed 17-19 g.
Animals were vaccinated intranasally on day 0, and day 14 with monovalent LPP virosomal influenza vaccine (A/Wyoming) and necropsied 21 days after the second vaccination.
Intranasal: test substances were inoculated intranasally (10 μl divided over both nostrils) under light Isoflurane/O2/N2O anaesthesia with the animal in dorsal position.
Prior to the first vaccination and 14 days after the first vaccination, orbital blood samples were collected under Isoflurane/O2/N2O anaesthesia. On day 35, the animals were sacrificed and blood samples were collected (exsanguinations under O2/CO2 anesthesia via the abdominal aorta or cardiac puncture). Serum from all samples was harvested, deep frozen, and stored in polypropylene tubes at <−10° C. until processing.
Influenza virus agglutinates red blood cells (RBCs), which is blocked in the presence of sufficient specific antibody to the virus. This phenomenon provides the basis for the hemagglutination inhibition (HI) assay, which is used to detect and quantify specific antiviral antibodies in serum. Sera were added to influenza virus and turkey RBCs. Several dilutions were tested (titration). The HI titer is defined as the reciprocal of the highest dilution that still inhibits hemagglutination. Geometrical Mean Titers (GMT) were calculated as follows:
HI titers were summarized by vaccination group and day, using geometric mean titers. Log-transformed day 35 HI titers of the groups were analyzed by means of linear regression, to investigate the dose-response relationship between the amount of LPP in the vaccine and the GMTs.
Results
HI Titer Analysis
GMTs are shown in Table 5.
On day 0, no HA-specific antibodies could be detected in the mice (i.e. all HI titers <10). On day 14, no HA-specific antibodies could be detected in most of the mice vaccinated by the intranasal route (i.n.). All HI titers were ≦10, except for one mouse in group A (HI titer: 80), one mouse in group C (HI titer: 35) and one mouse in group D (HI titer: 160).
On day 35 a dose-response in generation of HA-specific antibodies was observed, i.e. the addition of more LPP to the vaccine led to higher antibody titers.
The (log-transformed) day 35 HI titers were compared between the groups by means of linear regression. The fitted regression slope was highly significant (P<0.0001). Thus, the observed dose-response relationship between the amount of LPP in the vaccine and the GMTs was statistically significant.
Conclusion:
Repeated intranasal vaccination of mice with the non-adjuvanted reconstituted influenza virosomes did not induce a measurable systemic immune response. Repeated intranasal vaccination using LPP adjuvanted reconstituted influenza virosomes at the same HA dose level (2 μg HA/dose) and with a rising dose of LPP showed a systemic immune response in an LPP-dose depended fashion. In sharp contrast to the present invention (see Example 2 below), these data were previously considered supportive for the consensus opinion in the art that the use of an immunostimulant (in this case LPP) is essential for intranasal vaccination with inactivated influenza vaccine, even if the influenza antigen (HA) is presented in a reconstituted virosome.
Healthy human volunteers were intranasally vaccinated with LPP (lipopeptide) adjuvanted reconstituted influenza virosomes at a dose volume of 0.2 ml (0.1 ml per nostril) containing 150 mcg HA/mL per strain and 315 mcg LPP/mL. A similar group was intranasally vaccinated with reconstituted influenza virosomes without LPP at a dose volume of 0.2 ml (0.1 ml per nostril) containing 150 mcg HA/mL per strain. The objective of the study was to confirm in man the proof of concept as was shown in mice that to obtain a satisfactory systemic immune response after intranasal vaccination with an inactivated influenza vaccine the use of an adjuvant (e.g. LPP) is required.
Study Design:
This was a double-blind, randomized parallel group study in healthy young subjects aged ≧18 and <40 years. The study was performed in one study center: Swiss Pharma Contract Ltd., Basel, Switzerland. The principle investigator was Dr. M. Seiberling. The study had two parts. In Part I the safety of the LPP adjuvanted virosomal subunit influenza vaccine was assessed in 12 subjects. Nine subjects were vaccinated with LPP-RVM (LPP-Reconstituted viral membranes; Influenza vaccine—surface antigen, inactivated, virosome—, adjuvanted with LPP) and three subjects with RVM (Influenza vaccine—surface antigen, inactivated, virosome—). In Part II of the study the efficacy and safety of LPP-RVM was assessed in one hundred subjects (50 per group).
The study was performed in healthy subjects. In addition, the subjects participating in Part II of the study were not vaccinated against influenza during three years previous to the start of the study. This increases the homogeneity of the study population in Part II by minimizing the number of subjects with pre-existing antibodies against influenza.
Part I:
During 14 days prior to vaccination (Visit 1), after the subject had given informed consent, he or she was screened for in- and exclusion criteria and underwent a physical exam. At this visit a sample of nasal epithelial cells was harvested for cytology and baseline cilia activity was measured with the saccharine test.
At Visit 2 (Day 1) a 4-6 mL blood sample was taken for standard hematology analysis, a 6-10 mL blood sample was taken for standard biochemistry analysis and vital signs were assessed. After randomization the subject was vaccinated with one of the two vaccine formulations and remained at the site for the first twenty-four hours after vaccination to monitor immediate local and systemic reactions and adverse events. Vital signs were assessed four and twenty-four hours after vaccination. In addition, after twenty-four hours two blood samples were taken for standard hematology (4-6 mL) and biochemistry (6-10 mL) analysis; a sample of nasal epithelial cells was harvested for cytology and cilia activity after vaccination was measured with the saccharine test. Subjects were given a questionnaire (Questionnaire I) to take home to assess local and systemic reactions on the following day (Day 3).
The subject had to return to the study site two days after their release: Visit 3 (Day 4). At this visit local and systemic reactions were assessed and any spontaneous adverse events that occurred between the previous and the present visit were recorded. In addition, two blood samples were taken for standard hematology (4-6 mL) and biochemistry (6-10 mL) analysis and vital signs were assessed.
The subjects returned to the study site two weeks after the first vaccination on Day 15 (Visit 4). At this visit a sample of nasal epithelial cells was harvested for cytology, cilia activity was measured with the saccharine test and adverse events that occurred between Visit 3 and Visit 4 were recorded.
Part II:
During 14 days prior to the first blood and nasal wash sampling (Visit 1), after the subject had given informed consent he or she was screened for in- and exclusion criteria and his or her health was checked by physical examination.
At Visit 2 (Day—1; this visit can be combined with Visit 1) a 6 to 10 mL blood sample was taken for baseline Hemagglutination Inhibition (HI) titer determination and blood samples were taken for standard hematology (4-6 mL) and standard biochemistry (6-10 mL) analysis. A nasal wash sample was collected for determination of the baseline nasal IgA antibody titer.
The following day, at Visit 3 (Day 1) after assessment of vital signs, the subject was randomized to be vaccinated with a single dose of one of the two formulations of the nasal influenza vaccine. Any immediate local reactions, systemic reactions and adverse events were monitored at the site during the first hour after vaccination. Thereafter, vital signs were reassessed and the subject received a questionnaire to take home to record daily local and systemic reactions for the first seven days after vaccination.
Two weeks later (Visit 4; Day 15), a 6-10 mL blood sample was taken for HI titer determination, two additional blood samples were taken for standard hematology (4-6 mL) and biochemistry (6-10 mL) analysis, a nasal wash sample was taken for nasal IgA antibody titer.
Efficacy Assessments
To assess efficacy, blood samples and nasal wash samples were collected on Day-1 (baseline) and Day 15.
Blood Samples
Six to ten mL blood was collected to determine Hemagglutination Inhibition (HI) antibody titers.1 After blood collection and coagulation (at least 30 minutes at room temperature) sera were separated and kept frozen (−20° C.) until titration. Antibody titrations were done in duplicate. The titer assigned to a sample was the geometric mean of the two determinations. Pre- and post-vaccination sera were be titrated simultaneously.
1Palmer D F, Dowdle W R, Coleman M T, Schild G C. Hemagglutination Inhibition Test. Advanced laboratory techniques for influenza diagnosis. U.S. Dept. Hith. Ed. Welfare, P.H.S. Atlanta; 1975:25-62
Nasal Wash Samples
For the collection of nasal wash samples, 6 mL of pre-warmed saline (37° C.) was applied under rhinoscopic control in one nostril. The subject was requested to incline his/her head at a 60° angle so that the washing fluid could flow. The collected wash was applied to the second nostril which was washed under the same conditions. To the samples a preservative solution was added ( 1/100th of sample volume). The preservative solution contained 10 mg/ml bovine serum albumin dissolved in 100 mM Tris-HCl buffer, pH 8. Samples were directly clarified by low-speed centrifugation (10 min at 800×g) and aliquoted (to avoid repeated thawing of the samples later on) and placed on dry ice before transfer to −80° C.
IgA levels in the nasal wash samples were determined by ELISA, and statistically analyzed with the Wilcoxon test. The influenza vaccine was used as coating antigen in 96-well plates. Non-specific binding sites were blocked by incubation with a blocking buffer. The nasal washes were applied in two-fold dilutions (twelve dilutions per sample) in blocking buffer for the absorption of the influenza specific antibodies to the antigens on the 96-well plate. The 96-well plates were washed before incubation with enzyme conjugated anti-human antibodies (horse radish peroxidase or alkaline phosphatase conjugated). The non-bound anti-human antibodies were removed by washing and the amount of influenza strain specific antibody was determined by measuring the optical density after addition of the substrate for the enzymatic reaction.
Vaccine Formulation
Two different formulations of influenza vaccine were used in this study. Both formulations contained the viral antigens as recommended by the WHO for the southern hemisphere for the year 20052 at a dose level of 30 mcg per strain per dose of 0.2 ml
2WHO. Recommended composition of influenza virus vaccines for use in the 2005 influenza season. Weekly Epidem Rec. 2004; 79:369-376
A/New Calcdonia/20/99 (H1N1)-like strain
A/Wellington/1/2004 (H3N2)-like strain
B/Shanghai/361/2002-like strain
Briefly, inactivated influenza virus in a 30-40% sucrose solution was sedimented by centrifugation. The virus was resuspended and solubilized in a buffer containing the detergent octaethylene glycol monododecyl ether (OEG). Subsequently, viral nucleocapsid was removed by ultracentrifugation. The OEG-containing supernatant was adjusted with the lipopeptide P3CSK4 in OEG-containing buffer or OEG-containing buffer only in the case of LPP-free reconstituted viral membranes (P3CSK4: N-palmitoyl-S-[2,3-bis(palmitoyloxy)-(2RS)-propyl]-[R]-cysteinyl-[S]-seryl-[S]-lysyl-[S]-lysyl-[S]-lysyl-[S]-lysine). OEG was removed by adsorption to a hydrophobic resin. This resulted in the formation of LPP-containing or LPP-free reconstituted viral membranes (reconstituted viral vesicles with HA and NA in their membranes and, optionally, LPP in their membranes). After OEG removal, the virosomes were filtered through a PVDF membrane with a pore size of 0.22 μm.
For each strain of virus a separate preparation was made, either with or without LPP (Table 6). The amounts of LPP added corresponded to HA/LPP ratio's of 1:0.7 (w/w).
a Lowry assay, principle: Proteins form a blue colour after treatment with alkaline copper sulphate and Folin-ciocalteu phenol reagent. The protein content is determined from the absorbance at 750 nm, using
b PhEur: monograph 2053 and section 2.7.1
c Principle: Each phospholipid contains a single phosphor atom, which can be used for the quantification of the phospholipids. The phospholipids are destructed by perchloric acid and the phosphate generated is complexed by molybdate
d Ph. Eur. 2.6.14
e The Ovalbumine ELISA is a direct sandwich enzyme immunoassay using immobilized polyclonal anti-ovalbumin antibodies for capture and anti-ovalbumine-HRP conjugate as detection system. Conjugate and samples are
f According to monograph 0869 and 2053: The purity of the monovalent pooled harvest is examined by polyacrylamide gel electrophoresis. Electrophoresis: according Ph. Eur 2.2.31
Efficacy
Per viral strain, log-transformed HI antibody titers Day 15 and nasal IgA antibody titers at Day 15 were compared between the two vaccination groups by means of Wilcoxon's rank-sum test, at the two-sided significance level 0.05.
HI antibody titers at Day 15 were also analyzed by calculating the following three parameters per viral strain and per vaccination group:
the seroprotection rate, with seroprotection defined as a HI titer ≧40
the seroconversion rate, with seroconversion defined as a pre-vaccination HI titer <10 and a post-vaccination HI titer ≧40 or a pre-vaccination HI titer ≧10 and a post-vaccination rise in HI titer of at least 4-fold
the mean fold increase, i.e. the geometric mean of the fold increases in HI titer.
The efficacy data were analyzed both according to the per-protocol and the intent-to-treat principle. However, given that this was a so-called proof-of-principle study, the per-protocol analysis was considered the primary one. The intent-to-treat sample was constituted by the vaccinated subjects with some post-vaccination efficacy data. The per-protocol sample was constituted by the vaccinated subjects who completed the protocol and for whom no major protocol violations occurred. Major violations included (amongst others): violation of the in- or exclusion criteria and use of forbidden medication. Furthermore, subjects with a laboratory confirmed intercurrent influenza infection and subjects missing primary efficacy data were also excluded from the per-protocol sample. Whether or not a subject was to be excluded from the per-protocol sample was decided before the study database was unblinded.
Results
Note:
*Geometric mean.
RVM: Virosomal Influenza Vaccine
LPP-RVM: Virosomal Influenza Vaccine adjuvanted with Lipopeptide
Unexpectedly and in contradiction with the preclinical data obtained with the same vaccine batch (example 1) and as described in WO 04/110486 and clinical data (Gluck U, Gebbers J O, Gluck R, Phase 1 evaluation of intranasal virosomal influenza vaccine with and without Escherichia coli heat-labile toxin in adult volunteers. J. Virol. 1999 September; 73(9):7780-6), a satisfactory systemic immune response in accordance with the CHMP criteria for influenza vaccines was observed in the human group vaccinated only once with the non-adjuvanted reconstituted virosomal influenza vaccine.
This application claims priority to U.S. Provisional Patent Application No. 60/784,462 filed Mar. 22, 2006, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 60784462 | Mar 2006 | US |
