Gilead Hedges Against Eventual Generic Competition For Atripla With Bristol HIV Pact

The two companies hope to repeat their Atripla success story by teaming up to develop a new combination drug for HIV containing Gilead's cobicistat and Bristol's atazanavir.

Having partnered successfully in the past, Gilead Sciences, Inc. and Bristol-Myers Squibb Co. announced a licensing agreement Oct. 26 that would combine the virology-focused biotech's boosting agent with the big pharma's blockbuster protease inhibitor into a single-dose pill for HIV patients.

The once-daily dosing option will combine Bristol's Reyataz (atazanavir), which posted sales of $1.5 billion in 2010, with cobicistat, an agent meant to increase the levels of some HIV medications in the blood. The combination already is being tested in Phase II and Phase III in treatment-naïve HIV patients (Also see "In HIV Research, A Race For The Cure Is Back On Track " - Scrip, 1 Oct, 2011.).

"A fixed-dose protease inhibitor is very positive since all pills have to be boosted by with Norvir," wrote Deutsche Bank analyst Robyn Karnauskas, referring to Abbott's protease inhibitor ritonavir. "Meaning it's not one pill but rather two, which is less convenient."

Bristol will be responsible for the formulation, manufacturing, development, registration, distribution and commercialization of the combination, while Gilead will receive a royalty on the sales and be allowed to use cobicistat as both a standalone agent and in combination with other products. JPMorgan analyst Geoffrey Meacham expects the companies could file for approval of the combo pill as soon as the second quarter of 2012. Terms of the deal were not disclosed.

In June, Gilead signed a similar deal with Johnson & Johnson's Tibotec Pharmacueticals Ltd. that would create a fixed-dose antiretroviral therapy that combines Tibotec's Prezista (darunavir) with cobicistat. The companies also are negotiating rights to develop and market a separate single-tablet regimen of Prezista and cobicistat with Gilead's Emtriva (emtricitabine) and its pipeline candidate GS7340. The deal is expected to be finalized by the end of the year ([See Deal]).

"We believe protease inhibitor combinations further strengthen Gilead's position as a leader in HIV fixed-dose combination regimens beyond the QUAD/Complera," wrote Meacham in a note to clients.

Could Help Buffer Generic Competition To Atripla

If past efforts are any indication, the cobicistat-boosted Reyataz combo could prove very lucrative for both companies. Previously, Bristol and Gilead teamed up on the three-in-one combination pill Atripla, a combination of Gilead's Truvada (emtricitabine/tenofovir) and Bristol's Sustiva (efavirenz).

Atripla currently is the best-selling HIV drug in the world with sales of $2.9 billion in 2010. Yet, Sustiva is set to go off-patent in 2013 and Gilead has been preparing to lose one component of its best-selling franchise.

The market has been waiting for Gilead's next-generation Atripla, a four-in-one combination pill called Quad that has shown promising results in late-stage studies when tested against various combinations of HIV medications. Gilead is set to file an NDA for Quad, and analysts believe it could receive FDA approval as early as the second quarter of next year. Quad combines Truvada with cobicistat and the integrase inhibitor elvitegravir (Also see "Gilead's Quad Poised To Take Chunk Of Atripla's Market, If Phase III Results Hold Up" - Pink Sheet, 14 Sep, 2010.).

Gilead also is developing cobicistat as a standalone booster that could be used with other combinations, a market currently dominated by Abbott's Norvir. Yet, due to side effects, there is demand for alternatives. In a study of 79 patients presented in 2010, cobicistat had similar efficacy and safety to Norvir, up to 48 weeks. The Gilead booster did show some signs of increasing serum creatinine, a marker of kidney function, but the findings were inconclusive. It could mean that doctor will have to monitor a patient's kidney health.

Further data comparing cobicistat with Norvir, both partnered with Reyataz and Truvada, are expected in the fourth quarter. The company has said that it will file an NDA for cobicistat in the second quarter of 2012.

- Lisa LaMotta ([email protected])