Thursday, Gilead Sciences Inc (NASDAQ:GILD) shared topline results from an interim analysis of its Phase 3 PURPOSE 1 trial indicating its twice-yearly injectable HIV-1 capsid inhibitor, lenacapavir, demonstrated 100% efficacy for the investigational use of HIV prevention in cisgender women.

PURPOSE 1 study met its key efficacy endpoints of the superiority of twice-yearly lenacapavir to once-daily oral Truvada (emtricitabine 200mg and tenofovir disoproxil fumarate 300mg; F/TDF) and background HIV incidence (bHIV).

Based on these results, the independent Data Monitoring Committee (DMC) recommended that Gilead stop the blinded phase of the trial and offer open-label lenacapavir to all participants.

"With zero infections and 100% efficacy, twice-yearly lenacapavir has demonstrated its potential as an important new tool to help prevent HIV infections," said Merdad Parsey, MD, PhD, Chief Medical Officer, Gilead Sciences.

There were 0 incident cases of HIV infection among women in the lenacapavir group (incidence 0.00 per 100 person-years).

The results demonstrated the superiority of twice-yearly lenacapavir over bHIV (primary endpoint, incidence 2.41 per 100 person-years) and superiority of twice-yearly lenacapavir over once-daily Truvada (secondary endpoint), with p<0.0001 for both endpoints.

In the trial, lenacapavir was generally well-tolerated and no significant or new safety concerns were identified.

HIV incidence in the Descovy group was numerically similar to that in the Truvada group and was not statistically superior to bHIV.

Gilead expects results in late 2024/early 2025 from the program's other pivotal trial, PURPOSE 2, which is assessing twice-yearly lenacapavir for PrEP among cisgender men.

Price Action: GILD shares are up 8% at $68.20 at last check Thursday.

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