The Food and Drug Administration has approved a new form of pre-exposure prophylaxis (PrEP) for preventing cases of HIV. The treatment is called Apretude, and it’s the first PrEP medication to be taken via injection instead as a once-daily pill. Apretude will only need to be taken once a month initially, then every two months, likely providing a more convenient option for many people.

The first PrEP treatment, Truvada, was approved by the FDA in 2012. In 2019, Descovy became the second PrEP treatment to be approved. Both were developed by Gilead Sciences and rely on a two-drug combination of existing antivirals commonly used to treat HIV. When taken as prescribed, PrEP is highly effective at preventing sexually transmitted HIV infections (around 99% effective), though it’s less effective (74%) at preventing infection contracted from sharing contaminated needles.

The growing use of PrEP has likely contributed to declining rates of new HIV infections seen recently in the U.S., but its implementation has run into stumbles. The brand-name drugs have been relatively expensive, costing over $1,500 per month without insurance. Until recently, even PrEP users with insurance still often faced high out-of-pocket costs. And it’s only this year, following lengthy resistance by Gilead, that other drug manufacturers were allowed to widely produce a generic equivalent to Truvada, which has led to a sharp price drop for the treatment.

Outside of cost, the once-daily dosage for PrEP presented a challenge, since many people eligible for the treatment may not be able or willing to maintain their regimen. So Apretude may provide more opportunities for PrEP to be used.

The drug is an extended-release injectable suspension of the HIV antiviral cabotegravir, developed by ViiV Healthcare. It’s been approved for teens and adults who are considered to be at higher risk for contracting HIV-1, the primary subtype of the virus in the U.S. People starting on Apretude will take it once a month for the first two months, and then every two months afterward. Those considering Apretude can also first take the oral version of cabotegravir for a month, to assess its tolerability.

“Today’s approval adds an important tool in the effort to end the HIV epidemic by providing the first option to prevent HIV that does not involve taking a daily pill,” said Debra Birnkrant, director of the Division of Antivirals in the FDA’s Center for Drug Evaluation and Research, in the FDA’s announcement of the approval. “This injection, given every two months, will be critical to addressing the HIV epidemic in the U.S., including helping high-risk individuals and certain groups where adherence to daily medication has been a major challenge or not a realistic option.”

Though Apretude may represent an important step forward for HIV prevention, it will not come cheaply. The list price of the drug is expected to run around $3,700 per dose, according to NBC News. Over a year’s time on a six-dose schedule, the drug will cost around $22,000 a year, or roughly the same amount that Truvada did yearly. Starting this year, however, many health coverage plans will be required to pay the entire costs of PrEP, without any out-of-pocket costs for users. But high list prices can still limit the availability and affordability of a drug, particularly for uninsured people.