Merck and Gilead Sciences reported contrasting late-stage outcomes on Monday, pairing a promising advance in HIV treatment with the discontinuation of a high-profile lung cancer trial after underwhelming survival results.
On the infectious disease front, the companies announced positive Phase 3 findings for their investigational once-weekly oral HIV regimen combining islatravir and lenacapavir. Results from the ISLEND-1 and ISLEND-2 trials showed that the single-tablet regimen was as effective as standard daily antiretroviral therapies, including Gilead’s Biktarvy, in maintaining viral suppression through 48 weeks in patients already controlled on treatment.
If approved, the therapy could become the first long-acting oral option for HIV, offering an alternative between daily pills and injectable regimens. Analysts noted that the approach may appeal to a subset of patients seeking less frequent dosing while remaining on oral therapy. The data also reinforce Gilead’s leadership in HIV innovation and could help Merck expand its footprint in a therapeutic area where it has historically played a smaller role.
The companies did not disclose detailed efficacy or safety figures but said full results will be presented at an upcoming medical meeting. Regulatory submissions based on the ISLEND program are planned in multiple regions.
That progress, however, was tempered by disappointing news from oncology. Merck and Gilead said they will halt the Phase 3 KEYNOTE-D46 (EVOKE-03) study, which was evaluating a combination of Gilead’s antibody–drug conjugate Trodelvy with Merck’s immunotherapy Keytruda in patients with PD-L1–positive metastatic non–small cell lung cancer.
An independent monitoring committee determined that while the combination showed a numerical improvement in progression-free survival compared with Keytruda alone, the difference did not meet statistical thresholds. The panel also concluded that a meaningful overall survival benefit at final analysis was unlikely, leading the partners to discontinue the trial.
For Gilead, the decision adds to a series of challenges for Trodelvy in lung cancer. A successful first-line NSCLC indication was viewed as a potential driver of faster growth for the drug, but earlier studies have also failed to demonstrate a clear survival advantage in this setting.
Taken together, the announcements underscore the divergent trajectories that can emerge within large clinical portfolios: a potential breakthrough in HIV balanced against renewed hurdles in solid tumor oncology.
