Back to science today. Many of you read something in the paper or heard a report on the news about the "magic bullet" for breast cancer, otherwise known as TDM1, that was reported at the ASCO meetings. This indeed is a major scientific breakthrough as it pairs a powerful toxic agent that kills malignant cells with with other hybrids that enable the death of cancer cells without harming normal ones. Presto: cancer control without horrible side effects. Less good news: this particular agent is only helpful for women with metastatic her2 positive breast cancer (although it is good to remember that virtually all drugs are first tested in individuals with advanced cancer and then moved back to the adjuvant setting) and that is clearly delayed cancer progression, but defiitely did not end it or cure the disease. Still, this is progress, and suggests all sorts of possibilities in the years ahead.
This is a report from Laura Nikolaides at NBCC, a particularly clear and balanced account. I give you an excerpt and then a link:
T-DM1: ASCO Showcases a Victory for Science, But Is It a Victory for Women?
By Laura Nikolaides, Director of Research and Quality Care Programs
At 12 months, 84% of those on T-DM1 were still alive, compared to 77% on XT, and at two years that gap had widened to an 18% difference, 65% alive on T-DM1, compared to 47% on XT. Statistically, it is still possible that the differences in survival could be due to chance and will need confirmation in the final analysis. There were five adverse events leading to death in the XT arm, compared to one in the TDM1 arm, cardiotoxicity was minimal, at less than 2% in both arms. The main T-??DM1 toxicities were low platelet counts and abnormal liver function, which the investigators reported were reversible, while those on XT experienced more nausea, hand-foot disease, diarrhea and hair loss.
"These results left me feeling cautiously optimistic that this new agent does indeed deliver meaningful benefit to women with HER2+ metastatic breast cancer, with less toxicity."
These results left me feeling cautiously optimistic that this new agent does indeed deliver meaningful benefit to women with HER2+ metastatic breast cancer, with less toxicity. And there is no doubt for me that the EMILIA results do represent a major victory for science, and may open the door to a long sought after goal for all cancer patients—being able to deliver toxic agents that kill malignant cells directly while avoiding damage to normal cells. According to an article in the New York Times, approximately 24 other similar agents, called antibody-drug conjugates, are in development. These antibody-drug conjugates, or hybrids, consist of antibodies that are linked to the chemotherapy agents. In the case of T-DM1, the monoclonal antibody Herceptin is attached to the chemotherapy emtansine, or DM1, a chemotherapy agent that is potent and intolerable if given directly to patients.