FDA sets June date for Gilead's twice-yearly HIV PrEP

Gilead Sciences' already dominant position in HIV pre-exposure prophylaxis (PrEP) could be extended if the FDA approves a new twice-yearly product later this year.

The US regulator has started a priority review of the injectable formulation of HIV-1 capsid inhibitor lenacapavir, which also has breakthrough status, and is due to deliver a decision on the marketing application by 19th June.

Lenacapavir is already approved by the FDA for the treatment of multi-drug resistant HIV under the Sunlenca brand name.

Gilead's new application is based on two phase 3 trials in thousands of individuals – PURPOSE 1 and 2 – which showed that two injections of lenacapavir respectively provided 100% protection against HIV infection in women and adolescent girls in South Africa and Uganda, and near-complete (99.9%) protection in a broad group of cisgender men and gender-diverse people.

There were no HIV infections among the lenacapavir cohort in PURPOSE 1 and just two in PURPOSE 2, according to Gilead, while in both trials the drug was significantly better at preventing HIV infections than the company's once-daily oral PrEP product Truvada (emtricitabine and tenofovir disoproxil fumarate).

With patents on Truvada now expired and generics in the market, Gilead is shifting its oral PrEP focus to follow-up Descovy (emtricitabine/tenofovir alafenamide, which made total sales of $2.1 billion last year from its use in HIV treatment and PrEP. Truvada made around $3 billion at its peak, with an estimated two-thirds of that total coming from use as PrEP.

Analysts at RBC Capital Markets have predicted twice-yearly lenacapavir could become a $2 billion product, and become a key component of Gilead's PrEP franchise as it tries to ward off a challenge from HIV market rival ViiV Healthcare, majority owned by GSK.

ViiV already has FDA regulatory approval for an injectable PrEP option – Apretude (cabotegravir) – but that needs to be dosed six times a year. It contributed £279 million ($351 million) in sales last year, up 93% on 2023, which shows the demand in the market for alternatives to daily oral PrEP.

PrEP – generally used by at-risk people such as an HIV-negative individual with an HIV-positive partner – requires high levels of adherence to be effective and the rationale is that injectables will make it easier for patients to avoid missing doses and compromising their protection.

"Today, we are one step closer to introducing the first-ever twice-yearly HIV prevention choice that could, if approved, help transform the landscape for individuals who need or want additional prevention options that better fit into their lives," commented Dietmar Berger, Gilead's chief medical officer.

"We're excited about the potential of lenacapavir to make a real difference in HIV prevention in the US and around the world, supporting the broader goal of ending the HIV epidemic for everyone, everywhere."

Last year, Gilead and MSD reported results from a phase 2 trial of a two-drug combination based on lenacapavir and experimental nucleoside reverse transcriptase translocation inhibitor islatravir that could control HIV infection with a single, weekly oral dose.