Triple-negative breast cancer is typically difficult to treat because these cancer cells lack estrogen and progesterone receptors as well as large quantities of HER-2/neu protein, all of which are targets of existing drugs. This type of cancer affects approximately 15 percent of all breast cancer patients.
Iniparib, an experimental medication belonging to a new class of drugs called PARP inhibitors, effectively shrank tumors and prolonged the time they took to progress, and in addition, increased survival time for women with the resistant cancer, according to phase II trial data published in the New England Journal of Medicine.
In the study, researchers randomized 123 triple-negative breast cancer patients to receive either one common combination of chemotherapy drugs, or that chemotherapy plus iniparib. The study authors found that more than half of the participants responded positively to the iniparib plus chemo treatment, compared to approximately one-third of the women treated with chemotherapy alone. The joint iniparib and chemo group lived an average of 12.3 months versus 7.7 months for women in the chemotherapy alone arm.
Though the amount by which iniparib was able to extend life expectancy may not sound so impressive, ACSH's Dr. Gilbert Ross believes the more important factor is that scientists are making breakthroughs in treating this type of breast cancer. “We hope survival can be extended longer in the future or that researchers come up with an actual cure instead. In the meantime, this is still cause for optimism. It seems to be progress against what is an extremely difficult to treat cancer variant.”