Gilead’s four-in-one HIV/AIDS pill is a go. The FDA approved the drug, to be sold under the brand name Stribild, for patients who have not yet been treated for their HIV infection.

The once-daily pill combines two components that were already on the market — emtricitabine and tenofovir disoproxil fumarate — with two newly approved agents, elvitegravir and cobicistat. The latter two ingredients work together: elvitegravir inhibits an enzyme that helps the virus replicate, and cobicistat inhibits enzymes that digest HIV drugs, prolonging elvitegravir’s impact.

The daily dose will cost patients $28,500 a year, which is just slightly over the minimum price 13 congressmen had feared.

The product’s profile also tracks closely with another Gilead HIV therapy, the category’s best seller Atripla which it co-markets with Bristol-Myers Squibb, but offers convenience and has been associated with less severe side effects, including insomnia and dizziness. Those differences could make for a more compelling sell, but not necessarily in all markets.

Healthcare analysts Ramya Kartikeyan and Brad Tebbets wrote that the drug offers a smart way for Gilead to extend its lead in the category while addressing impending patent expiries on its products. The two GlobalData experts predict that Gilead’s marketing approach will involve dividing the market based on income: promoting the side-effect advantage in wealthier countries where insurers are likely to pick up the tab, while in low-income countries sharing emtricitabine trade secrets in a play to cover the generics market. The analysts point to an agreement Gilead signed with generics firms Mylan, Ranbaxy and Strides Arcolab this month to manufacture the agent (which is also Atripla’s core ingredient) in developing regions. Emtricitabine is also contained in Gilead’s other mature HIV/AIDS blockbuster, Truvada.

Barclay’s analyst Tony Butler wrote in an August 28 research note that the sales strategy includes deploying 130 sales reps to market the drug in the US with Stribild as the priority and Gilead’s three-in-one HIV treatment Complera second. His forecast: peak US sales of $2.5 billion.

Kartikeyan and Tebbets proposed Gilead cut Stribild’s price so patients are less likely to migrate to generic meds as they become available.