FDA rejects two of the four drugs in Gilead's blockbuster HIV drug Stribild

The FDA has handed back a pair of new drug applications from Gilead ($GILD) covering key products used in its blockbuster four-in-one HIV-fighting therapy Stribild. The refusals for elvitegravir and cobicistat on a standalone basis were triggered after inspectors were left shaking their heads following a checkup on Gilead's "documentation and validation of certain quality testing procedures and methods."

Elvitegravir is an integrase inhibitor Gilead licensed from Japan Tobacco back in 2005, while cobicistat is a boosting agent used to amp up the punch behind Stribild, Gilead's new HIV drug approved last year. Gilead hastened to assure investors that the rejection will not affect Stribild's approval or use.

The inspection trouble, which Gilead says it is moving to address, is a rare setback for Gilead, which has been rewarded with some big upside projections on the four-in-one drug. EvaluatePharma recently tapped the drug--which uses two approved drugs found in Truvada--as the best performer in a new wave of drugs approved at the FDA. Analysts are now projecting sales of $2.38 billion in 2016, with some estimates reaching a peak of close to $5 billion, as an aggressive Gilead hurries to build blockbuster revenue.

Gilead priced Stribild at $28,500 last summer, earning a fresh round of caustic criticism from the HIV/AIDS community and kudos from analysts tracking the company's financial performance. Gilead is one of the most aggressive biotechs in the industry and is largely immune to negative reviews at this point.   

Marketing applications for these two drug ingredients are pending in Europe.

- here's the press release

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