The present invention relates to a method for predicting response of a cancer patient to anticancer drug as treatment.
As one of methods of cancer treatment, anticancer drug treatment is mentioned. However, pathological conditions of cancers are diversified depending on types of cancers, area of onset, or stage of cancer progression, and these diversifications and differences of responses of individual patient are responsible for the fact that there are many patients to whom anticancer drug treatment is not useful as well as patients to whom anticancer drug treatment is useful. Continued administrations of anticancer drugs to patients to whom anticancer drug treatment is not useful since to do so takes a close-up of bad side due to side effects of the anticancer drugs thereby causing sufferings to patients.
For this reason, various methods for predicting sensitivities of anticancer drugs based on gene expressed in vivo or proteins have been investigated.
The present invention is a method for predicting responses of patients to a chemotherapy or anti-cancer therapy which is useful as an index for judgment by physicians whether or not the specific treatment agent should be given to the patient. The major focus of the patent is to assess patients primary or metastatic tumors prior to neoadjuvant therapy. The invention will allow determination whether a patient should receive treatment or not. This will alleviate unnecessary treatment of patients in which the anticancer therapy is unlikely to significantly be effective. It will also allow screening of treatments of multiple drugs prior to use in patients using the assay. The uniqueness of the invention is its utility in predicting treatment outcome.
A first aspect of the present invention relates to a method for predicting a response of a cancer patient to anticancer drug, including steps of: acquiring specific activities of cyclin-dependant kinase 1 (CDK1) and CDK2 contained in a malignant tumor obtained from a cancer patient; obtaining a cell cycle profile score based on the specific activity of CDK1 (CDK1 specific activity) and the specific activity of CDK2 (CDK2 specific activity); and predicting a degree of the response to the anticancer drug based on the cell cycle profile score, wherein the CDK1 specific activity is represented by a ratio of an activity value of CDK1 to an expression level of CDK1 and the CDK2 specific activity is represented by a ratio of an activity value of CDK2 to an expression level of CDK2. The cell cycle profile score will be used to predict the patient's tumor (in vivo) response to the treatment. Specifically it will be aimed at neoadjuvant treatment of individuals with a known cancer comprising of single or multiple drug combinations given to a patient. Individual drug responses to the patients' tumor response will be assessed prior to and post neoadjuvant treatment. If the cell cycle profile score is higher (responsive rate is high; high being very responsive) then the patient is likely to benefit from treatment. If the patient score is low then the patient should not be given treatment.
A second aspect of the present invention relates to a method for predicting response of cancer patient to anticancer drug, including steps of: acquiring specific activities of cyclin-dependant kinase 1 (CDK1) and CDK2 contained in a malignant tumor obtained from a cancer patient; obtaining a cell cycle profile score (as described above) based on the specific activity of CDK1 (CDK1 specific activity) and the specific activity of CDK2 (CDK2 specific activity); and predicting a degree of tumor reduction based on the cell cycle profile score, wherein the CDK1 specific activity is represented by a ratio of an activity value of CDK1 to an expression level of CDK1 and the CDK2 specific activity is represented by a ratio of an activity value of CDK2 to an expression level of CDK2.
A third aspect of the present invention relates to a method for predicting a response of a cancer patient to anticancer drug, including steps of: acquiring specific activities of cyclin-dependant kinase 1 (CDK1) and CDK2 contained in a malignant tumor obtained from a cancer patient; obtaining a cell cycle profile score based on the specific activity of CDK1 (CDK1 specific activity) and the specific activity of CDK2 (CDK2 specific activity); and predicting a pathological complete response rate based on the cell cycle profile score, wherein the CDK1 specific activity is represented by a ratio of an activity value of CDK1 to an expression level of CDK1 and the CDK2 specific activity is represented by a ratio of an activity value of CDK2 to an expression level of CDK2.
The fourth aspect of the invention is it applies to multiple cancers such as melanoma, sarcoma, and breast, colorectal, gastric, lung, esophageal, pancreas, prostate, and other types carcinomas.
The fifth aspect of the invention is it applies to any chemotherapy or anti-cancer treatment currently available or developed in the future. The invention also covers combination of anti-cancer drugs.
The sixth aspect of the invention is to screen potential neoadjuvant treatment effectiveness as single and combination agents prior to neoadjuvant therapy.
Inventors find that a disease outcome can be predicted in the basis of a cell cycle profile score obtained by analyzing a tumor of patient. The disease outcome includes a complete response, a partial response, stable disease, no response, and time to progression of disease as patient's response to anticancer drug therapy. The cell cycle profile score is obtained based on the relationship between CDK1 specific activity and CDK2 specific activity in the tumor sampled from the cancer patient. Here, CDK1 specific activity represents CDK1 activity value/CDK1 expression level, and CDK2 specific activity represents CDK2 activity value/CDK2 expression level. CDK specific activity is a parameter reflecting CDK enzyme activity per unit CDK protein amount contained in a sample, is equivalent to, of CDKs present in the cell, ratio of CDK1 showing activity, and represents CDK activity level based on proliferative state of malignant tumor cells which are judgment object.
Above-mentioned cancers include epithelial derived tumors, hematopoietic organ derived cancers, sarcomas, or the like. As for types of cancers, for example, breast cancer, gastric cancer, colorectal cancer, esophageal cancer, lung cancer, prostate cancer, leukemia, sarcomas, or the like are mentioned. Anticancer drug means chemical substances having antitumor efficacy for above-mentioned cancers. Malignant tumor sampled from a cancer patient means a tumor of a tissue where control mechanism of proliferation is abnormal due to that, for example, harmony as an individual is spoiled in body tissue of the cancer patient.
In general, it may be considered that, since cancer cells proliferate actively exceeding normal proliferation control, when ratio of cells in S-phase that is DNA replication phase and in G2-phase from completion of DNA synthesis to commencement of mitosis is high, the cells already became cancerous. Further, since it is considered that aneuploidy observed with cancer cells is caused when cells passed M-phase that is a cell division phase in abnormal state, or proceeded to G1-phase without passing M-phase, and then proceeded to S-phase without change, it may be considered that cells concerned are already cancerous also when ratio of cells existing in M-phase is low.
CDK1 is a protein exhibiting activity when proceeding from G2-phase to M-phase of the cell cycle, and CDK2 is a protein exhibiting activity when proceeding from G1-phase to S-phase of the cell cycle. Therefore, CDK specific activity ratio (CDK2 specific activity/CDK1 specific activity) is a numeric figure which reflects how much cells in S-phase or G2-phase are greater than cells in M-phase and can be used as a parameter accurately reflecting proliferation potency of cells.
CDK activity value is, for example, kinase activity level (unit is expressed by U) calculated from the amount of substrate being phosphorylated by CDK. As for the substrate which is phosphorylated by CDK, for example, histone H1 is cited for active type CDK1 and active type CDK2. CDK activity value can be measured by known CDK activity measuring method. Specifically, such a method is used that a sample containing active type CDK is prepared from cell culture of a measurement sample, substrate protein is caused to incorporate 32P using the sample and 32P labeled ATP (γ-[32P]ATP), amount of labeling of 32P labeled phosphorylated substrate is measured, and is quantified based on a calibration curve prepared by a standard preparation. As for the method which does not use labeling of radioactive material, one described in US2002-0164673 is mentioned. According to this method, a sample containing target active type CDK is prepared from cell lysate of a specimen, adenosine 5′-O-(3-thiotriphosphate) (ATP-γS) is caused to react with the substrate to introduce mono-thiophosphoric acid group to serine or threonine residue of the substrate protein, substrate protein is labeled by causing a labeling fluorescent material or labeling enzyme to bind to sulfur atom of the mono-thiophosphoric acid group being introduced, amount of labeling of the labeled thiophosphoric acid substrate (amount of fluorescence when labeling fluorescent material is used) is measured, and quantification is made based on the calibration curve prepared by the standard preparation.
The sample to be used for activity measurement is prepared by specifically collecting a target CDK from lysate of a tissue containing malignant tumor that is used as a measurement object. The target CDK can be collected using, for example, anti-CDK antibody.
Expression level of CDK is the amount of the target CDK (unit corresponding to number of molecules) contained in the lysate of the tissue containing malignant tumors which are judgment object, and can be measured by a known method for measuring the amount of target CDK from above-mentioned lysate. For example, the amount of CDK may be measured using ELISA, western blot method, or the like or can be measured by the method disclosed in US2004-0214180. The target CDK is arrested using a specific antigen (anti-CDK antibody) and the CDK thus arrested is simply quantified.
(Reduction of Tumor)
The major focus of the assay invention is to determine the risk score of a patient's tumor in vitro with the specific assay to determine the potential that when the patient is treated with neoadjuvant therapy that one can predict before treatment potential responsiveness. If this can be achieved then a patient who is none responsive in the assay to single or multiple drug combination prior should not be given neoadjuvant therapy. On the other if the patient is significantly responsive to some degree then the patient should be given the drug. The invention would save unnecessary treatment of cancer patients with specific drugs and at the same time define drugs that are likely to work in vivo on the patients' tumor. This would be highly applicable to cancer patients being treated with neoadjuvant therapy such as breast cancer, melanoma, colon, gastric, lung, prostate cancer. Breast cancer being one of the cancers most often treated with neoadjuvant therapy is the primary target but not limited. Currently, neoadjuvant therapy of breast cancer involves giving treatment of a single or multiple drugs and wait and see if tumor reduction occurs.
(Cell Cycle Profile Score)
It is considered that, even if CDK activated in a certain cell cycle are less, cells are able to proliferate while other specific CDKs act in compensation fashion, and hence, even if specific CDKs are activated abnormally, it may be considered that cell kinetic is already in abnormal state.
Here, CDK1 specific activity (CDK1S/A) is considered to be a first risk factor, CDK specific activity ratio (CDK2 specific activity/CDK1 specific activity) to be a second risk factor, and possible relationship between the first and the second risk factors, and cancer recurrence risk is assessed, respectively. Here, it is supposed that probability of cancer recurrence has numerical assessment scale of risk score RS1 based on CDK1 specific activity (first risk factor). Further, it is supposed that probability of cancer recurrence has numerical assessment scale of risk score RS2 based on CDK specific activity ratio (second risk factor). If probability of cancer recurrence by the first and the second risks is represented by cell cycle profile score C2PS, this C2PS is given by a value proportional to a product of the risk score RS1 and risk score RS2.
Cell cycle profile score C2PS, risk score RS1 and risk score RS2 are obtained as follows:
In
C2PS=RS1×RS2=F(x)×G(y) (1)
RS1=F(x)=a/(1+Exp(−(x−b)×c)) (2)
RS2=G(y)=d/(1+Exp(−(y−e)×f)) (3)
(in the equation, a through f are constants)
Meanwhile, constants a through c are determined by the relationship between CDK1 specific activity and recurrence probability, and constants d through f are determined by the relationship between CDK2 specific activity/CDK1 specific activity and recurrence probability. For above-shown logistic functions in
As shown in
For example, all points on curve CL1 are points of CDK1 specific activity and CDK2 specific activity where cell cycle profile scores C2PS are identical, and all points on curve CL2 are points of CDK1 specific activity and CDK2 specific activity where cell cycle profile scores C2PS are identical. Since an area enclosed by the curves is the area where cell cycle profile score C2PS is always higher than points on the curve (see
As discussed above, 2-dimensional graph composed of a first CDK specific activity (x-axis) and a second CDK specific activity (y-axis) can be divided into areas each having different cell cycle profile scores C2PS by a curve (cut-off line) combining points where cell cycle profile scores C2PS are identical.
(Relationship Between Cell Cycle Profile Score and Reduction Rate of Tumor)
Next, CDK1 expression level, CDK1 active value, CDK2 expression level, CDK2 active value of malignant tumors collected by needle biopsy from breast cancer patients before receiving chemotherapy are measured, and CDK1 specific activity and CDK2 specific activity are obtained. The cell cycle profile score is obtained by above-shown equations and results are shown in Table 1. Reduction rates of tumors of each of patients after chemotherapy are also shown in Table 1. Meanwhile, the reduction rate of tumor is obtained by measuring a size of tumor tissue of each patient before and after the chemotherapy.
In Table 1, CDK1 SA denotes CDK1 specific activity, CDK2SA denotes CDK2 specific activity, C2PS denotes cell cycle profile score, and reduction rate of tumor denotes reduction rate of tumors after receiving the chemotherapy prescribed in the regimen. In the column of the regimen, “wT” means paclitaxel, “FEC” means fluorouracil, cyclophosphamide, epirubicin, “CE” means cyclophosphamide, epirubicin, “Doce” means docetaxel, “ZL” means zoladex, “TM” means tamoxifen, and “UFT” means uracil, tegafur.
Results of investigation of a relationship between the cell cycle profile score C2PS and reduction rate of tumors after receiving the chemotherapy revealed that there is a correlation between the two as shown in
(Relationship Between Cell Cycle Profile Score and Response Rate for Reduction of Tumor)
In Table 1, patients are listed in the order of smaller cell cycle profile scores. They are grouped so that 4 to 6 patients with smaller cell cycle profile scores may be in the same group. Specifically, patients 1 to 4 are assigned to a first group, patients 1 to 5 are assigned to a second group, patients 1 to 6 are assigned to a third group, patients 2 to 7 are assigned to a fourth group, and after that, groups consisting 6 patients are formed by shifting one patient. Next, mean value of cell cycle profile scores, frequency of appearance of patients with reduction rate of tumor greater than 50%, and frequency of appearance of patients with reduction rate of tumor greater than 80% are calculated for each of the groups. Results are shown in Table 2.
A graph is drawn based on results shown in Table 2, in which graph horizontal axis represents mean value of cell cycle profile scores and vertical axis represents frequency of appearance (reduction rate>50%). As shown in
Subsequently, as shown in
(Relationship Between Cell Cycle Profile Score and Pathological Complete Response)
For breast cancer patients listed in Table 3 shown below, CDK1 expression level, CDK1 active value, CDK2 expression level, CDK2 active value of malignant tumors collected by needle biopsy before receiving chemotherapy are measured, and CDK1 specific activity and CDK2 specific activity are obtained. Cell cycle profile scores are obtained based on above-shown equations and results are shown in Table 3. Further for each of patients shown in Table 3, whether or not pathological complete response (pCR) has been attained by the chemotherapy is shown in Table 3. In the column “pCR” in Table 3, “1” denotes pathological complete response.
Patients listed in Table 3 are grouped in the order of smaller cell cycle profile scores and shown in Table 4. Next, mean value of cell cycle profile scores and pCR rate are calculated for every group. Results are shown in Table 4.
A graph is drawn based on results shown in Table 4, in which graph horizontal axis represents mean value of cell cycle profile scores and vertical axis represents pCR rate, and is shown in
The method according to the present preferred embodiment is preferably executed by a computer system. The computer system for executing the method is described below.
The CPU 110a is capable of executing a computer program recorded in the ROM 110b and a computer program loaded in the RAM 110c. The ROM 110b comprises mask ROM, PROM, EPROM, EEPROM, etc. and is recoded with computer programs executed by the CPU 110a and data used for the programs.
The RAM 110c comprises SRAM, DRAM, etc. The RAM 110c is used to read out computer programs recorded in the ROM 110b and the hard disk 110d. And the RAM 110c is used as a work area of the CPU 110a when these computer programs are executed.
The hard disk 110d is installed with an operating system, an application program, etc., various computer programs to be executed by the CPU 110a, and data used for executing the computer programs. An application program 140a described later is also installed in this hard disk 110d.
The readout device 110e which comprises a flexible disk drive, a CD-ROM drive or DVD-ROM drive is capable of reading out a computer program or data recorded in a portable recording media 140. And the portable recording media 140 stores the application program 140a to function as a system of the present invention. The computer 100a reads out the application program 140a related to the present invention from the portable recording media 140 and is capable of installing the application program 140a in the hard disk 110d.
In addition to that said application program 140a is provided by the portable recording media 140, said application program 140a may be provided through an electric communication line (wired or wireless) from outside devices which are communicably connected to the computer 100a via said electric communication line. For example, said application program 140a is stored in a hard disk in an internet server computer to which the computer 100a accesses and said application program 140a may be downloaded and installed in the hard disk 110d.
The hard disk 110d is installed with an operating system which provides a graphical user interface environment, such as that sold under the trademark WINDOWS by Microsoft Corporation. In the explanation hereinafter, the application program 140a related to this embodiment shall operate on said operating system.
The input/output interface 110f comprises a serial interface, e.g. USB, IEEE1394, RS-232C, etc.; a parallel interface, e.g. SCSI, IDE, IEEE1284, etc.; and an analog interface e.g. D/A converter, A/D converter, etc. The input/output interface 110f is connected to the input device 130 comprising a keyboard and a mouse and users can input data into the computer 100a using the input data device 130.
The image output interface 110h is connected to the display 120 comprising LCD, CRT or the like so that picture signals corresponding to image data provided from the CPU 110a are output to the display 120. The display 120 displays a picture (screen) based on input picture signals.
The CPU 110a previously reads the expressions (1) through (3) stored in the hard disk 110d, and calculates a cell cycle profile score C2PS form the input parameter data (Step S12).
Next, the CPU 110a predicts and judges the response of the cancer patient to anticancer drug on the basis of the calculated cell cycle profile score C2PS (Step S13).
A first through fourth correlation equation are stored on the hard disk 110d beforehand. The first correlation equation relates to the correlation between cell cycle profile scores and reduction rates showed by
The CPU 110a obtains a reduction rate as the response of the cancer patient to anticancer drug on the basis of the calculated cell cycle profile score C2PS and the read out first correlation equation from the hard disk 110d. The CPU 110a obtains a response rate for 50% reduction of tumor as the response of the cancer patient to anticancer drug on the basis of the calculated cell cycle profile score C2PS and the read out second correlation equation from the hard disk 110d. The CPU 110a obtains a response rate for 80% reduction of tumor as the response of the cancer patient to anticancer drug on the basis of the calculated cell cycle profile score C2PS and the read out third correlation equation from the hard disk 110d. The CPU 110a obtains a response rate for pCR as the response of the cancer patient to anticancer drug on the basis of the calculated cell cycle profile score C2PS and the read out fourth correlation equation from the hard disk 110d.
The CPU 110a stores the obtained reduction rate, response rate for 50% reduction of tumor, response rate for 80% reduction of tumor and response rate for pCR in the hard disk 110d and display the reduction rate, response rate for 50% reduction of tumor, response rate for 80% reduction of tumor and/or response rate for pCR on the display 120 through the input/output interface 110f (Step 14).
In the present preferred embodiment, the activities of CDK1 and CDK2 and the expression levels of CDK1 and CDK2 are inputted via the input device 130; however, the input method is not limited thereto. For example, the data is not necessarily inputted by an operator, and the activities of CDK1 and CDK2 and the expression levels of CDK1 and CDK2 may be automatically obtained from a measuring device via the input/output interface 110f.
Pursuant to 35 U.S.C.§119(e), this document claims the benefit of the filing date of Provisional U.S. Patent Application Ser. No. 61/093,594 filed on Sep. 2, 2008, which is incorporated by reference herein.
Number | Date | Country | |
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61093594 | Sep 2008 | US |