At the HIV Analyst & Investor Event on Tuesday, Gilead Sciences Inc. (NASDAQ:GILD) revealed that it is developing a once-yearly injectable formulation for lenacapavir.

The annual formulation is currently in Phase 1 study, with data to be presented.

In its investor presentation, the company said it expects the pivotal Phase 3 pharmacokinetics study's first patient to be in 2025, and potential regulatory filings will begin in late 2027.

In September, Gilead revealed the results of an interim analysis from a second Phase 3 trial investigating the use of the company's twice-yearly injectable HIV-1 capsid inhibitor, lenacapavir.

Lenacapavir reduced HIV infections by 96% compared to background HIV incidence.

Also Read: HIV Drugmaker Gilead Reports Strongest Quarterly Performance Of 2024, Analysts Boost Price Target On Raised Outlook

In November, the New England Journal of Medicine published the full results from Gilead's Phase 3 PURPOSE 2 trial evaluating twice-yearly lenacapavir for HIV prevention.

The study found that twice-yearly lenacapavir for pre-exposure prophylaxis (PrEP) was highly efficacious at reducing HIV infections, reducing them by 96% compared to background HIV incidence.

Twice-yearly lenacapavir for PrEP also demonstrated superiority to once-daily Truvada (emtricitabine 200 mg and tenofovir disoproxil fumarate 300 mg; F/TDF) for PrEP and was generally well-tolerated, with no significant or new safety concerns identified.

In 2021, the FDA approved ViiV Healthcare's Apretude, the first injectable form of PrEP administered every two months.

Pfizer Inc (NYSE:PFE) and GSK Plc (NYSE:GSK) own ViiV Healthcare.

STAT News highlights that Gilead plans to seek approval for a PrEP injection that requires only two clinic visits per year. This less frequent dosing has been shown to be more effective than traditional daily oral PrEP.

However, global access to these new PrEP options remains a challenge. Former CDC director Rochelle Walensky criticized ViiV for not prioritizing accessibility in Africa and urged Gilead to ensure broader availability of its drug lenacapavir.

Unlike vaccines, which train the immune system to recognize and fight viruses long-term, PrEP relies on antivirals that are effective only while active in the body. The main challenge has been developing drugs that remain effective for extended periods.

While significant progress has been made with long-lasting PrEP, the same cannot be said for HIV vaccines.

Efforts to create a vaccine have struggled against the virus's complexity, and no vaccines are currently in late-stage trials following recent setbacks.

The success of long-term PrEP may further complicate vaccine development by reducing the urgency for alternatives.

Price Action: GILD stock is up 0.73% at $93.05 at the last check on Thursday.

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