Gilead goes long-acting in HIV

Gilead has finally got the FDA's nod for its novel HIV therapy, the long-acting capsid inhibitor lenacapavir, after previous issues with the vials in which the drug had been stored. The approval is in patients with multidrug-resistant HIV, who account for around 2% of the total HIV population, the company estimates.

The drug, branded Sunlenca, will be priced at $42,250 for the first year and $39,000 per year thereafter, a spokesperson for Gilead told Evaluate Vantage. This compares favourably to a $40,000-50,000 annual list price for GSK/Viiv’s long-acting therapy Cabenuva. Sunlenca is injected subcutaneously once every six months, while Cabenuva – used in patients without resistance – is given monthly or every other month.

Sunlenca was approved in the EU in August for the same treatment-resistant population, but hopes that it will become a blockbuster hinge on expansion into earlier HIV use; studies in pre-exposure prophylaxis are ongoing, as are a number of combination trials.

The most advanced combo is with Merck & Co’s nucleoside reverse transcriptase translocation inhibitor islatravir. A phase 2 study of a once-weekly oral formulation is set to restart soon, after an earlier clinical hold spurred by toxicity fears around the Merck project. The study will now use a lower islatravir dose than previously, but the exact dose has not yet been publicly disclosed.

Neither has the new timeline for readout been revealed. More details are expected next year when the study resumes.

However, Gilead has long sought to keep its options open regarding the best add-on to lenacapavir. Data are due next year from a phase 1 trial of a combo of lenacapavir and broadly neutralising antibodies; the ultimate aim of this regimen is to provide an HIV cure (Aids 2022 preview – Gilead shoots for an HIV cure, July 27, 2022).

Meanwhile, in pre-exposure prophylaxis, Gilead has one fewer potential rival after Merck withdrew islatravir from this race. Data are expected in 2024 from Gilead’s Purpose-1 and 2 Prep trials, the first in young women and the second in men who have sex with men. Purpose 3 and 4, in US women and IV drug users respectively, are “poised to begin in 2023”, Gilead told Vantage.

Gilead has made a start, but it still has a long way to go to make lenacapavir the next big thing in HIV.

This article has been updated to clarify islatravir's mechanism of action.