Breast Cancer “Smart Bomb” From Roche, ImmunoGen Shows Tumor Shrinkage in Big Test
The “smart bomb” drug for breast cancer from Roche and Waltham, MA-based ImmunoGen looks to have passed an important test.
Full data aren’t being released yet, but ImmunoGen (NASDAQ: IMGN) today disclosed an interesting tidbit in a regulatory filing on its new version of trastuzumab (marketed as Herceptin) that combines an antibody with a toxin to give it more potency against breast cancer. The drug, T-DM1, caused tumors to at least partially shrink for about one-third of patients (32.7 percent) whose disease worsened after treatment with the regular version of trastuzumab and a competitor, lapatinib (Tykerb). This was an early peek at results from a 110-patient clinical trial that will be presented this weekend at the San Antonio Breast Cancer Symposium.
The filing doesn’t provide any detail on the side effect profile of the drug, how long the patients stayed in remission after getting the drug, or whether they actually lived longer than they otherwise would with standard treatment. But tumor shrinkage was the main goal of the study and this looks like the compelling data that ImmunoGen and Roche were hoping for, which I described in a preview story on Monday. Another trial of 112 patients presented earlier this year found that tumors shrank for about one-fourth of patients on T-DM1, without the heart-damaging side effect that’s been observed with the older version of trastuzumab. If these new results are compelling enough, ImmunoGen CEO Dan Junius told me, they could prompt Roche to seek FDA approval for the new drug in 2010, without having to wait for results from a bigger study of 580 patients, which started in February.
ImmunoGen isn’t commenting on the latest tidbit of data, preferring to wait until the full results are reported in San Antonio this weekend. But shareholders liked the news. Shares of ImmunoGen climbed 3 percent to $8.43 at 1:45 pm Eastern after the regulatory filing crossed the wire.
Krysta Pellegrino, a spokeswoman for the Genentech unit of Roche, says more details on the trial are expected out at 7 am Central time on Saturday in San Antonio. She couldn’t comment further.