T-DM1 improves survival, submitted for FDA approval

Earlier this week, it was announced that survival data are in for T-DM1, an experimental breast cancer drug for HER2-positive breast cancer, and the results are positive. We just don't know how positive. Survival data will be announced at an upcoming medical meeting. My bet is either the ASCO Breast Cancer Symposium in September or the San Antonio Breast Cancer Symposium in December. We'll soon see how long we have to wait for the results. At the annual meeting of the American Society of Clinical Oncology earlier this summer, it looks like there may be quite a survival curve (read "ASCO Updates: " 'Super Herceptin' Excels in HER2 Breast Cancer"). Although there appeared to be a survival advantage in the T-DM1 arm, researchers could not confirm a positive benefit until a certain number of events were reached. However, at the two-year follow-up, 65.4 percent of patients on T-DM1 were alive compared with 47.5 percent on the standard treatment of Xeloda (capecitabine) and Tykerb (lapatinib). So, a recap: T-DM1 is one of a reformulated class of drugs called antibody-drug conjugates. It fuses together the Herceptin antibody (trastuzumab) to a potent drug called emtansine, packing a powerful punch to cancers that are fueled by overexpression of the HER2 receptor--even in patients whose cancers have progressed with Herceptin. Emtansine's potency is at least 100 times more powerful than paclitaxel, and administration without severe side effects has been a challenge until now. Linking it to Herceptin, which delivers it directly to the cancer cell, reduces those side effects. In fact, T-DM1 had fewer side effects than the standard treatment.In addition, the company that has developed T-DM1 submitted the drug to the FDA for approval this week (read full statement here). Genentech had applied for accelerated approval for T-DM1 back in 2010, but the FDA passed. The agency explained that in that particular study, the patients had not exhausted all treatment options before receiving T-DM1. It would be surprising if the FDA did not approve T-DM1 on the current data, though. You can read more about T-DM1 and updates in HER2-positive breast cancer in our recent article, "Research Unravels New Ways to Treat HER2-Positive Breast Cancer."