WASHINGTON, Dec. 7 (Xinhua) -- The use of two drugs never tried in combination before in ovarian cancer resulted in a 70 percent destruction of cancer cells already resistant to commonly used chemotherapy agents, say researchers at Mayo Clinic in Florida.

Their report, published on-line Wednesday in Gynecologic Oncology, suggests that this combination, ixabepilone and sunitinib, might offer a much needed treatment option for women with advanced ovarian cancer.

Neither drug is approved for use in ovarian cancer. Ixabepilone is a chemotherapy drug that, like other taxane drugs, targets the microtubules and stops dividing cells from forming a spindle. It has been approved for use in metastatic breast cancer. Sunitinib, approved for use in kidney cancer, belongs to a class of tyrosine kinase inhibitors that stops growth signals from reaching inside cancer cells.

When caught at late stages, ovarian cancer is often fatal because it progressively stops responding to the chemotherapy drugs used to treat it.

"Women die from ovarian cancer because their tumors become resistant to chemotherapy, so a drug that might be able to reduce that resistance -- which may be what this combination of agents is doing -- would be a boon to treatment of this difficult cancer," says study coauthor Gerardo Colon-Otero.

The finding also highlights the importance of the role of a molecule, RhoB, that the researchers say is activated by the drug duo. It might be a potential biomarker that may help identify patients who might benefit from such combination therapy, the researchers say.