Gilead Sciences and Johnson & Johnson’s Tibotec Pharmaceuticals have agreed to work together to develop a once-daily, single tablet fixed-dose combination of Tibotec’s protease inhibitor Prezista® (darunavir) and Gilead’s pharmacoenhancing agent, cobicistat, for the treatment of HIV-1 infection. The companies are also negotiating terms for a future single-tablet regimen (STR) containing Prezista, Gilead’s Emtriva® (emtricitabine) and its experimental agents, GS 7340 and cobicistat. Tibotec will assume global responsibility for the fixed-dose combination drug, while Gilead would be responsible for the worldwide development and commercialisation of the new STR.