GlaxoSmithKline's (NYSE:GSK) solution to its HIV drugs losing market share: If you can't beat them, find a partner with a nice pipeline. The British pharmaceutical giant is teaming up with Pfizer (NYSE:PFE) to create a joint venture.

Glaxo's HIV franchise has been hurting because of tough competition, with sales down 5% last year. Merck (NYSE:MRK) and Johnson & Johnson (NYSE:JNJ) both have new drugs on the market, and Glaxo was hurt by a National Institutes of Health clinical trial last year that concluded that Gilead Sciences' (NASDAQ:GILD) Truvada HIV combo drug worked better than Glaxo's Epzicom.

Glaxo will own 85% of the yet-to-be-named company because it is donating most of the 11 drugs that the company will market. Pfizer's 15% stake would go up if the clinical-stage drugs that are added to the joint venture become successes, however.

Clearly, giving the sales reps more drugs to sell should create some efficiency, but the best part of joining forces is that the companies will be free to create combination pills from both their arsenals. Patients love the convenience of a single pill, and the virus hates the tag-team effort. For instance, sales for Gilead's and Bristol-Myers Squibb's (NYSE:BMY) triple combination drug Atripla increased 74% to more than $1.5 billion last year. A little bit of that kind of magic and the joint venture surely would be a success.

This really looks like a good deal for both big companies. Between the efficiencies, potential increased sales from combination drugs, and decreased development risk now that it is shared between the two, the combination is likely to be more successful than the two individuals could be.

Just don't name the new company GlaxoSmithKlinePfizer. Please.

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