Gilead Sciences Inc. (GILD) dropped a pile of clinical updates, and the headline numbers are the kind that make a biotech investor sit up. The company reported positive trial data for its twice-yearly HIV prevention injection and its primary biliary cholangitis treatment. Two different diseases, two different stories, but the same theme: persistence and durability.

Higher Persistence In PURPOSE 5 HIV Prevention Study

In the Phase 2 PURPOSE 5 study, the biopharmaceutical developer evaluated twice-yearly injectable lenacapavir against daily oral emtricitabine/tenofovir disoproxil fumarate (F/TDF) for pre-exposure prophylaxis (PrEP). The trial enrolled 267 participants across the U.K. and France who were not taking PrEP at enrollment, including cisgender men, cisgender women, and gender-diverse individuals.

PURPOSE 5 represents the first randomized study specifically designed to compare persistence between a long-acting regimen and daily oral medication in individuals not currently on PrEP. That's a mouthful, but the point is simple: nobody had directly tested whether a shot every six months beats a pill every day when it comes to actually sticking with the regimen.

Week 52 data on Friday demonstrated that 85.6% of lenacapavir recipients maintained strict persistence, compared with 46.3% of participants on daily oral pills. Zero HIV infections occurred in the lenacapavir cohort over 52 weeks, whereas one individual acquired HIV in the oral group after taking fewer than two doses weekly.

Read that again. The shot didn't just match the pill. It nearly doubled the persistence rate, and nobody in the injection group got HIV. The one infection in the oral group happened in someone who wasn't taking the pill as prescribed, which is exactly the problem daily PrEP has always faced.

Livdelzi Delivers Sustained Alkaline Phosphatase Reductions

On Thursday, the company released detailed 52-week findings from the Phase 3 IDEAL study evaluating Livdelzi (seladelpar) in primary biliary cholangitis. By Week 52, 75.4% of participants treated with Livdelzi achieved the alkaline phosphatase (ALP) normalization composite endpoint, compared with 16.1% of patients receiving placebo.

ALP serves as an essential biomarker of disease activity, with higher levels linked to liver failure and poorer long-term clinical outcomes. In other words, getting ALP down isn't just a lab number. It's a signal that the liver might hold up longer.

Therapeutic benefits began swiftly, as 52.3% of Livdelzi patients met the composite goal after one month versus 6.5% on placebo, with the response sustaining through Week 52. That's a fast onset and a durable effect, which is the combination you want in a chronic liver disease drug.

Safety profiles across both trials proved consistent with previous research. Serious adverse events in the liver study occurred in 3.1% of Livdelzi participants versus 12.9% on placebo, with no events linked to the study drug. Fewer serious events than placebo is not a typo. It's just what the data showed.

GILD Price Action: Gilead Sciences shares were up 0.46% at $169.11 at the time of publication on Monday, according to market data.