Immunogen Halts Study as Cancer Drug Flops, Shares Fall

Xconomy Boston — 

Immunogen has been trying to prove that it can turn its “smart bomb” drug technology into a successful drug without the help of a big pharma partner. Those plans took a big hit today as its lead drug candidate flopped in a mid-stage clinical trial.

Waltham, MA-based Immunogen (NASDAQ: IMGN) today stopped a Phase II study of IMGN901, an experimental drug it has been testing as a treatment for small cell lung cancer, or SCLC. The results weren’t pretty: not only did an independent data monitoring committee find the drug ineffective, but it also saw that patients receiving the treatment had higher rates of infection and infection-related deaths than those getting standard treatments alone. One patient in the trial died of an infection that was possibly drug related. Shares of Immunogen fell more than 20 percent in pre-market trading.

“This is clearly a disappointing outcome, as there is a tremendous need for new treatment options for SCLC,” said Immunogen executive vice president and chief development officer Charles Morris, in a statement. “We will be analyzing the findings to date in this trial as part of assessing potential next steps for IMGN901.”

Immunogen gave its drug in tandem with chemotherapy drugs etoposide and carboplatin to patients with SCLC, and compared the results to those taking etoposide and carboplatin alone. The trial was designed to assess IMGN901’s ability to keep tumors from spreading. IMGN901 targets CD56, a cellular target found on the surface of B cells.

Immunogen, of course, played a role in the development of the Roche breast cancer drug ado-trastuzumab emtansine (Kadcyla), which was approved by the FDA earlier this year. The drug is one of an emerging class of antibody-drug conjugates, which combine the targeting capability of an antibody with the cell-killing abilities of a toxin, creating something of a “smart bomb” effect on tumors. The breast cancer treatment’s approval was noteworthy for Immunogen, because Roche licensed Immunogen’s technology to soup up its successful cancer drug trastuzumab (Herceptin) and create it. Amgen, Sanofi, and Novartis have also tapped into Immunogen’s technology to see if they can make souped-up antibody drugs.

But even though FDA approval of the Roche drug was validation for Immunogen’s technology, sales of the drug only provide a small royalty stream for the Waltham company. It has been working for years to show it can create an effective antibody-drug conjugate in-house and become a drugmaker in its own right. Now it looks like that’s going to have to wait for good data from one of Immunogen’s other wholly owned programs.