Gilead Sciences' (Nasdaq: GILD) new motto: If at first you don't succeed at diversification, try, try, and try again.

The HIV specialist bought CV Therapeutics for instant diversification with its heart drug, Ranexa. It took a medium-term view acquiring Myogen, getting Letairis, which was approved eventually, and darusentan, which flopped in phase 3 trials.

Now Gilead is taking an even earlier view to boosting its pipeline, picking up privately held CGI Pharmaceuticals, which doesn't seem to have any drugs in the clinic yet. Gilead is paying up to $120 million for CGI, which is broken up into some undisclosed combination of a large up-front payment and milestone payments based on its progress in clinical development.

CGI's biggest asset is its library of more than 50,000 kinase inhibitors, at least one of which is ready to move into the clinic, according to its website.

In its announcement, Gilead highlighted CGI's spleen tyrosine kinase (Syk) inhibitor, which could be used for treating inflammatory diseases such as rheumatoid arthritis. Syk is a promising target, but Gilead could be late to the party, with Rigel Pharmaceuticals (Nasdaq: RIGL) and AstraZeneca (NYSE: AZN) teamed up on Syk inhibitor R788, which has already completed phase 2 trials. Still, that leaves 49,999 more potential pipeline boosters.

And Gilead could certainly use the help. Its HIV drugs have dominated over offerings from GlaxoSmithKline (NYSE: GSK) and others, but that has left the company relying solely on a few of its drugs for a majority of its income. In its latest quarter, sales of its top three drugs --Atripla, Truvada, and Viread -- which all treat HIV, were 73% of total revenue, and Gilead has to share revenues from Atripla with Bristol-Myers Squibb (NYSE: BMY).

The purchase of CGI won't pay off for many years, but I like the strategy of buying a company focused on bringing non-HIV compounds into the clinic. The purchase is relatively cheap compared with licensing late-stage compounds, and Gilead has plenty of free cash flow to support the drugs once they make it into the clinic.

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Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. The Fool owns shares of GlaxoSmithKline and has a disclosure policy.