Better breast cancer drug in sight for Genentech
Researchers reported last week on a study of 137 patients who were randomly assigned to receive the original trastuzumab (Herceptin) along with chemotherapy, or a new souped-up antibody drug called T-DM1 from Genentech, of South San Francisco, Calif., and Waltham’s ImmunoGen Inc. The study, among women getting their first round of therapy, showed 48 percent had tumor shrinkage with the new drug; 41 percent did as well on standard treatment. Only 37 percent of women on the new drug had clinically relevant adverse events, compared with 75 percent on standard therapy.
This is still just a mid-stage clinical trial, and researchers don’t know if the new drug is better at keeping tumors from spreading, which is the main goal.
But it is another intriguing step forward for T-DM1, which could become one of the first drugs to successfully combine the precise targeting capability of an antibody with a super-potent toxin to kill tumor cells.
Genentech is betting the new drug will improve upon the original, which generates more than $5 billion in annual sales.
“We are encouraged by the results,’’ Edith Perez, a researcher at the Mayo Clinic and the lead investigator of the trial, said in a statement. “The study demonstrated that T-DM1 has very good antitumor activity as well as much lower toxicity.’’
Genentech had hoped to win FDA approval of T-DM1 based on a separate study that showed promising tumor shrinkage in much sicker patients who were receiving their third round of therapy.
But in August, the FDA said it would not consider that application for a faster-than-usual approval. That study continues.
Genentech is also testing its new drug on more than 1,000 patients receiving their initial round of treatment.
Oct 12, 2010