It's official. For better or worse -- we'll know in five to 10 years -- Gilead Sciences (Nasdaq: GILD) is a cancer drug company.

The traditional HIV drug powerhouse has been not-so-slowly bringing cancer drugs into the fold. Late last year, Gilead acquired Arresto Biosciences and last month it bought Calistoga Pharmaceuticals.

Now Gilead has established a research partnership with Yale University. The company will provide $40 million for the first four years, which could be upped to $100 million if the partnership is extended for up to 10 years. Gilead will get the first right of refusal for any drugs that are developed through the collaboration.

As they say, "You're not a real drug developer unless you have a partnership with a university for basic research."

OK, so no one actually says that. But they should.

Gilead joins the big boys in going back to school. Pfizer (NYSE: PFE) has a collaboration with seven New York hospitals and the University of California, San Francisco. sanofi-aventis (NYSE: SNY) also has a separate collaboration with UCSF. And Sanford-Burnham Medical Research Institute is getting funding for research on Alzheimer's disease and major psychiatric disorders from Johnson & Johnson (NYSE: JNJ).

This is a long-term commitment to cancer drugs by Gilead -- not just because the collaboration could go on for a decade, but because anything that comes out of the research will presumably be pre-clinical-trial-stage compounds. It's going to take a long time for them to work their way through development.

Gilead is clearly committed to the move into oncology. While I like the enthusiasm, and the company has money to burn, I wonder if cancer is really the best niche for Gilead. It's a competitive space with a disease that isn't very forgiving in clinical trials.

At this point, investors can't do much but watch and wait; it'll be years before we know if Gilead was able to duplicate the success it's had in HIV drugs.

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