When ovarian cancer is diagnosed in late stages it is often fatal because it stops responding to the chemotherapy drugs used to treat it. But researchers at the Mayo Clinic in Florida found that two drugs never tried in combination before in ovarian cancer resulted in a 70 percent destruction of cancer cells already resistant to chemotherapy drugs.
The study also highlights the importance of the role of a molecule, RhoB, that the researchers say is activated by the drug duo. The researchers had identified RhoB as a key modulator for drug response in other tumor types, but say its role in ovarian cancer was unknown before this study. Now we have evidence that this combination of drugs prompts an increase in RhoB and cancer cells die.
In order to test the drug combo, the researchers created two new laboratory cell lines. They were developed from tumor tissue specimens taken from a patient with metastatic cancer whose tumors had stopped responding to multiple chemotherapy drugs.
In both cell lines the cell kill was significantly greater with the drug combination than either drug alone. For example, in chemotherapy-resistant lines (where this potential combination therapy will most likely be used), ixabepilone alone killed up to 30 percent of cells, and the rate for suntinib was up to 10 percent. When the agents were used together, the kill rate was 70 percent.
Neither drug is currently approved for use in ovarian cancer. Ixabepilone is a chemotherapy drug that has been approved for use in metastatic breast cancer and Sunitinib is approved for use in kidney cancer.
While further study is needed, this combination (ixabepilone and sunitinib), might offer a much needed treatment option for women with advanced ovarian cancer. And as RhoB is a potential biomarker, it may help identify patients who might benefit from such combination therapy.