METHODS FOR PREDICTING A CANCER PATIENT'S RESPONSE TO SUNITINIB
The present invention provides methods for individualizing chemotherapy for cancer treatment, and particularly for evaluating a patient's responsiveness to sunitinib prior to treatment. The method comprises expanding malignant cells in culture from a patient's tumor specimen, contacting the cultured cells with one or more active agents including sunitinib, and evaluating or quantifying the response to the active agent(s). The result of the assay is a dose response curve, which may be evaluated using algorithms described herein, so as to quantitatively assess drug sensitivity. The in vitro response to the drug as determined by the method of the invention is correlative with the patient's in vivo response upon receiving sunitinib during chemotherapeutic treatment, in the course of standardized or individualized chemotherapeutic regimen.
1 . A method for predicting the efficacy of sunitinib for a cancer patient, comprising:
culturing malignant cells from a tumor specimen from the patient;
contacting the cultured cells with sunitinib; and
evaluating the response of the malignant cells to sunitinib.
2 . The method of claim 1 , wherein the cancer is selected from a renal cell carcinoma, gastrointestinal stromal tumor, or breast cancer.
3 . The method of claim 1 , wherein the cancer is breast cancer.
4 . The method of claim 1 , wherein the malignant cells are cultured from a plurality of tumor explants in a monolayer culture.
5 . The method of claim 4 , wherein the tumor explants are prepared by mechanical fragmentation of the patient's tumor specimen.
6 . The method of claim 5 , wherein the tumor specimen is minced.
7 . The method of claim 6 , wherein the explants measure from about 0.25 to about 1.5 mm 3 .
8 . The method of claim 4 , where the monolayer cells are suspended in culture media, and the cells plated for chemosensitivity testing.
9 . The method of claim 8 , wherein at least 5 dilutions of sunitinib are added across a plurality of wells within the range of about 0.05 μM to about 75 μM.
10 . The method of claim 8 , wherein from 2 to 6 doses of sunitnib are added across a plurality of wells within the range of about 0.4 μM to about 15 μM.
11 . The method of claim 1 , wherein sunitinib is contacted with the cells for about 3 days, and then cell viability quantified.
12 . The method of claim 11 , wherein cell viability is quantified by visible light, UV light, or fluorescent light.
13 . The method of claim 12 , wherein cells are stained with DAPI.
14 . The method of claim 1 , wherein the response of the cells to sunitinib is evaluated by preparing a dose response curve, and determining an adjusted AUC (aAUC).
15 . The method of claim 14 , wherein the aAUC assigns weights relative to the degree of change in cytotoxicity between dose points.
16 . The method of claim 15 , wherein changes in cytotoxicity between dose points are quantified by a local slope, and the local slopes weighted along the dose-response curve to emphasize cytotoxic responses.
17 . The method of claim 16 , wherein aAUC is calculated by:
calculating a Cytotoxity Index (CI) for each dose;
calculating a local slope (S d ) at each dose point;
calculating a slope weight at each dose point, by W d =1−S d ; and
calculating aAUC, where aAUC=ΣW d CI d , and where d represents each dose in a range.
18 . The method of claim 17 , wherein aAUC is calculated for a truncated dose response curve.
19 . The method of claim 17 , further comprising, assigning the tumor sample as being responsive, non-responsive, or intermediate responsive to sunitinib.