Bristol-Myers Squibb and Gilead Sciences have entered a licensing agreement for the development and commercialisation of a new fixed-dose combination pill for HIV-infected patients.

The combination pill includes Bristol-Myers’ protease inhibitor Reyataz (atazanavir sulfate) and Gilead’s cobicistat, a pharmacoenhancing agent that increases blood levels of certain HIV medicines to enable a dosing of one pill per day.

Reyataz is a prescription drug used in combination with other medicines to treat HIV infected patients aged six or older, and cobicistat is a mechanism-based inhibitor of cytochrome P450 3A, an enzyme that metabolises drugs in the body.

Under the deal, Bristol-Myers will pay Gilead an undisclosed royalty based on annual net sales of the product.

Under the agreement, Bristol-Myers will be responsible for the commercialisation, development, distribution, formulation, manufacturing and registration of Reyataz and cobicistat as a fixed-dose combination.

Gilead will retain exclusive rights to manufacture, develop and market cobicistat as a stand-alone drug and for use in combination with other agents.