ImmunoGen Emerges from Genentech’s Shadow With Novel Cancer Drugs

Xconomy Boston — 

When ImmunoGen (NASDAQ: IMGN) said yesterday that it had started human trials of a new drug to treat ovarian cancer and other solid tumors, the announcement marked a coming out of sorts for the Waltham, MA-based company. That’s because for most of the past decade or so, ImmunoGen has been inextricably linked with biotech giant Genentech, which has been using ImmunoGen’s technology to develop a breast cancer drug called emtansine (T-DM1). The drug has proven so promising in late-stage trials that hopes for an approval have pushed shares of ImmunoGen—which will collect single-digit royalties on the product should the FDA green-light it—up 30 percent in the last three months to $17.27. ImmunoGen also announced a secondary stock offering yesterday, though it did not say how much it hopes to raise.

ImmunoGen’s ovarian cancer drug, called IMGN853, is wholly owned by ImmunoGen, so if it opts to take it through the whole process and the product is approved, the company won’t have to share the proceeds with anyone. Furthermore, IMGN853 is the second such proprietary ImmunoGen drug to hit clinical trials this year. In April, ImmnoGen announced that its drug to treat non-Hodgkin’s lymphoma, IMGN529, was also starting human trials. Both drugs still have several years of development ahead of them, but that didn’t lessen CEO Daniel Junius’s optimism when he spoke to Xconomy in May. “It’s quite exciting,” Junius said. (The company was in a quiet period following the announcement of the secondary offering and declined to comment for this story.)

ImmunoGen’s base technology platform is used to make antibody drug conjugates (ADCs), which are antibodies that are linked to toxins designed to boost their potency. T-DM1 is an ADC that connects Genentech’s hit breast cancer drug, trastuzumab (Herceptin), to a toxin—creating a sort of smart bomb that can burrow into cancer cells and kill them.

Junius said that ImmunoGen’s ovarian cancer ADC employs a special linker technology—one of four in the company’s arsenal—which imbues it with the ability to counteract resistance that’s often seen in cancer treatments. The first trial will involve 64 patients with three different types of drug-resistant ovarian or lung tumors. He said in the previous interview that the company is pursuing a “pretty aggressive protocol” that should reveal insights about the drug’s effectiveness and side effects by mid-2013.

The lymphoma drug, IMGN529, addresses an emerging cancer target called CD37, which is a protein that’s prevalent in some forms of non-Hodgkin’s lymphoma and chronic lymphocytic leukemia. The first trial will enroll 55 lymphoma patients.

Junius said that in animal models, IMGN529 appeared to be as effective as rituximab (Rituxan), Genentech’s blockbuster drug to treat non-Hodgkin’s lymphoma. “We’re able to add the ADC dimension to it, while not losing the therapeutic benefit of the antibody,” he said. “We think that makes it quite interesting.”

ImmunoGen was founded in 1981 and has racked up an impressive list of Big Pharma partners. In addition to Genentech (a unit of Swiss drug giant Roche), the company has development deals with Amgen, Bayer HealthCare, Eli Lilly, Novartis, and Sanofi. The nine Wall Street analysts covering the company estimate that revenues from these deals will grow 150 percent in the year ending June 2013, to $41.4 million, according to Thomson Financial Network.

The partnerships have been more than just a source of revenue, Junius said. They’ve also been vital to bolstering confidence in the ADC technology. “Even at the board level there was some concern over whether the technology would have viability,” he said. “We needed the collaborations to address all the complexities associated with these multi-element compounds. I refer to [the years of partnering] as a gestation period that has allowed us to address issues with the technology, and give it the breadth of potential we enjoy today.”