about a portfolio with high profile candidates, but they’re not [FDA] approved, then we’ll be disappointed,” Reyes says.
OK, so I asked him to describe what he considers the company’s three most exciting cancer drug candidates in the pipeline and why. Here are the highlights.
—-GA 101. This is what Reyes called a “third-generation” form of rituximab, which he mentioned last March at the company’s R&D summit. The drug is made knock out excessive B cells, that can cause inflammation, hitting the same CD20 target blocked by the original. The difference is that the newer version is engineered to spark more of an immune-system reaction against cancer cells, and trigger a programmed cell death process called apoptosis, Reyes says. Studies in primates suggest the newer drug is more potent at depleting excess B cells, and that it lasts longer. Specifically, the study showed that B cells in primates didn’t recover after 35 days if they got GA101, but those cells started coming back for Rituxan-treated animals.
While Reyes says the effect on B cells is “profound,” he cautions, “It’s too early to say how this will translate in humans.”
Still, it’s not too hard to imagine how this might be used. If this is a more potent, longer-lasting CD20 blocker, then maybe it could be an option for patients who relapse after getting treated with the original.
—Next up was BIIB22, a drug made to hit a target on cells called insulin like growth factor-1. This is an especially crowded corner of cancer drug development, with at least 10 companies pursuing their own drugs, including Pfizer and Schering-Plough, Reyes says.
“Since we’re not first-in-class, we need to be best-in-class,” Reyes says.
The company is doing this by developing an antibody drug that binds differently with the target than other drugs. Biogen hopes will provide a better side effect profile, namely hyperglycemia (excessive high blood sugar associated with diabetes) or thrombocytopenia (reduced numbers of clot-forming platelet cells). Biogen is also exploring biomarkers of individual patients, to see if it can separate likely responders from non-responders, which could end up making this drug like Genentech’s trastuzumab (Herceptin), used by about one-fourth of breast cancer patients.
—The last candidate Reyes wanted to single out was its heat-shock protein 90 blocker. It has two of these drugs in the pipeline, an oral pill, and an intravenous form. Pfizer, Bristol-Myers Squibb and Cambridge, MA-based Infinity Pharmaceuticals are a few of the competitors in this segment of cancer drugs. Scientists have long been intrigued by Hsp-90 blockers, because this pathway serves a critical stabilizing, or chaperoning, role in supporting other rapid-cell growth proteins associated with tumors. If you block Hsp90, the thinking goes, these other proteins will crumble and trigger cell suicide process in cancer cells.
Biogen expects to get its first glimpse at early proof of concept data by the end of 2009 to see if the drug justifies the big-time money and manpower required for late-stage clinical trials. Reyes said he’s high on this drug because it’s a synthetic small-molecule compound, instead of one derived from natural products, which he thinks gives the drug a combination of high potency with minimal side effects.
