Triple negative breast cancer is a feared subtype of the disease. It is called that because it lacks the estrogen and progesterone receptors and the Her-2 gene mutation, any one of which provides a target for anti-cancer treatment. It can be quickly lethal and is seen in the young women who inherit one of the BRCA gene mutations who get cancer before they can have their breasts removed prophylactically. Most treatments have been either only marginally effective or totally ineffective. Now comes from the Massachusetts General Hospital Cancer Center a brand new approach. Saddled with the amazing name of Sacituzumab Govitecan-hziy, this new drug uses a variant of Irinotecan, usually used to treat colon cancer, attached to an antibody against a protein made by many aggressive cancers. That antibody delivers the business end of the molecule, the anti-cancer half, to the tumor cell.
Published in the New England Journal of Medicine on February 21, this article describes young women who had received a median of three prior different chemotherapy regimens for triple negative metastatic breast cancer: a third saw a major shrinkage of their tumors. They lived an average of only thirteen months, but much longer than expected. The drug has not yet been tested in women earlier in the course of this disease, who would be expected to see greater benefit.
Dr. Stark comments: “This drug is a home run in the cancer world. It opens up a new way to treat this dreaded variant of breast cancer. Antibody-drug conjugates have been around for a long time, but this one is a stroke of genius. I can’t wait to see what happens next.”