Bristol-Myers Squibb (NYSE:BMY) and Gilead Sciences (NASDAQ:GILD) have taken a much-needed step that should make patients' lives easier even as it improves the companies' results.

The two firms announced Monday that they will collaborate to create the first once-daily combination pill for the treatment of HIV infection. The joint venture will bring together Bristol-Myers' Sustiva with Gilead's Truvada, which is itself a pairing of that firm's two anti-HIV medications, Viread and Emtriva. The move in part comes in response to a call earlier in the year by U.S. Secretary of Health and Human Services Tommy Thompson for a simplified regimen for HIV/AIDS treatment.

Gilead has built its business around HIV medicines, but the company's research focus is now shifting to hepatitis B and C. The company continues to position its HIV franchise for growth, however. Truvada, its combination of two already-approved drugs, was approved just this past August. Gilead has also been conducting a study comparing treatment with Viread and Emtriva plus Sustiva to treatment with GlaxoSmithKline's (NYSE:GSK) Combivir plus Sustiva. Gilead recently released data showing its combination had fewer adverse events than the Glaxo regimen.

HIV is less of a priority for Bristol-Myers. Sustiva sales were $157 million in the third quarter, out of revenue of $5.4 billion, although the HIV medication's sales were up 65% from the same period last year. In any case, the linkup should keep Sustiva selling briskly.

Since all three drugs are already approved, Bristol-Myers and Gilead will probably be able to gain quick clearance from the Food and Drug Administration for the three-in-one pill. Given its convenience, the new medicine may become the standard therapy for HIV/AIDS patients, a fact that is likely to make both patients and the drugs' makers happy.

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Fool contributor Brian Gorman is a freelance writer living in Chicago. He does not own shares of any companies mentioned here.