Supercharged Herceptin Nears Pivot Point, as ImmunoGen, Roche Await Data on Breast Cancer “Smart Bomb”

ImmunoGen has been in business for 28 years without developing a single FDA approved drug. This week, after all those lean years, the Waltham, MA-based biotech (NASDAQ: [[ticker:IMGN]]) and its partner, Roche, are getting ready to show the world they have something big for patients with breast cancer.

The company is striving to develop the world’s first commercially successful “smart bomb” cancer drug, a dream that’s eluded cancer researchers for three decades. The drug from Roche, enabled by technology from ImmunoGen, combines the specific tumor-targeting ability of an engineered antibody, but (here’s the special part) attached to a chemical toxin that packs an extra tumor-killing kick. In this case, ImmunoGen and Roche have taken one of biotech’s most successful plain-vanilla antibodies, trastuzumab (Herceptin), and essentially supercharged it with one of those toxins.

Compelling evidence to support this drug, called T-DM1, has been mounting for two years, and this coming Saturday, researchers at the San Antonio Breast Cancer Symposium are expected to unveil data that could provide enough evidence for the companies to seek FDA approval. This has big ramifications for patients, and investors. The old workhorse version of trastuzumab, first approved by the FDA in 1998, is a mega-hit—with $5 billion in worldwide sales, even though it is only prescribed for about one-fourth of breast cancer patients with a certain gene mutation. The new souped-up version could be an even bigger seller, analysts say. And because ImmunoGen makes technology that can link any antibody drug to a toxin, it stands to collect sizable royalties not just on TDM1, but other drugs like it in the future. Savvy biotech investors are already picking up on this, as ImmunoGen stock has doubled this year.

“This is a big deal for the all the right reasons,” says ImmunoGen CEO Dan Junius. “It may be transformative.”

Dan Junius
Dan Junius

This drug first arrived on my radar back in April 2007, when I was at Bloomberg News. Ian Krop, an oncologist at the Dana-Farber Cancer Institute in Boston told me: “It’s unlikely this will cure breast cancer, but it’s got a good chance of being a really helpful weapon. We’re about as excited about this one as we can get this early in the game.”

Two months later, researchers showed a glimpse of what Krop was talking about. Four out of 10 patients in a study had their tumors shrink when taking T-DM1, researchers at the American Society of Clinical Oncology (ASCO) reported in 2007. That was striking because the tumor shrinkage happened in very sick patients whose cancer had spread through their bodies, and who had failed to respond to other therapies. Side effects were minimal.

Fast forward to the most recent ASCO conference in June. The numbers were a little more modest—only one out of four patients (25 percent) who got the experimental drug

Author: Luke Timmerman

Luke is an award-winning journalist specializing in life sciences. He has served as national biotechnology editor for Xconomy and national biotechnology reporter for Bloomberg News. Luke got started covering life sciences at The Seattle Times, where he was the lead reporter on an investigation of doctors who leaked confidential information about clinical trials to investors. The story won the Scripps Howard National Journalism Award and several other national prizes. Luke holds a bachelor’s degree in journalism from the University of Wisconsin-Madison, and during the 2005-2006 academic year, he was a Knight Science Journalism Fellow at MIT.