The company is currently developing GVAX, an immunotherapy vaccine that is in Phase III clinical trials for prostate cancer and Phase II for leukemia and pancreatic cancer. It is also developing a Phase I bladder-cancer drug based on a modified adenovirus (the virus that causes the common cold) that attacks tumor cells while sparing healthy ones. And while the technology is still unproven, Sherwin recalls the initial skepticism the scientific and financial community had toward monoclonal antibodies. It's an analogy he takes to heart: The work of Abgenix's researchers is behind the newly approved colon-cancer drug Vectibix, a monoclonal antibody that Amgen is now hoping to turn into a blockbuster. (Amgen completed its acquisition of Abgenix last year.) Here Sherwin talks about the many evolutions of Cell Genesys, why he believes the company's current development programs can overcome early failures in the field, and what he thinks about the skepticism toward new technologies.
Why has Cell Genesys gone through so many evolutions over the past 15 years?The interesting thing about biotechnology start-ups is that what they focus on is very much a reflection of what people will pay for—and that has moved around. When we started Cell Genesys, there was a lot of interest in new technologies, and that was the intent of our original business plan. We were interested in cellular therapies—hence the name Cell Genesys—and our program was primarily focused on T cell therapy in HIV infection. But we recognized that that was an area with higher risk, and we were interested in technologies that were a little less risky and perhaps closer to the market.
Where is your focus now?
In the mid-'90s, just as we were spinning out Abgenix, we concluded that it was going to be tough to commercialize T cell therapy for HIV. It was around that time new drugs for HIV infection, like protease inhibitors, were coming to market, and what was once viewed as a hopeless disease—where all extraordinary therapies needed to be considered—had become a product disease.
In 1997, we acquired Somatix, which had just started work on something called GVAX. By the late '90s, we had reformatted GVAX to create a prostate-cancer product.
What distinguishes GVAX from other immunotherapy products?
There are different approaches to immunotherapy relating to how you format your product and how you try to stimulate the immune system. That said, the biggest difference between companies in the field is the need to pick the right molecular target. Generally speaking, immunotherapies are slow-acting, and attempting to use them rapidly in aggressive cancers where patients have short survival rates is an impossible challenge to overcome. And many of the failures that have occurred are easily explained because companies attempted to do just that.