A once-weekly oral HIV treatment combining islatravir and lenacapavir achieved its primary efficacy endpoint in two Phase 3 trials, bringing the investigational regimen closer to becoming the first approved long-acting oral HIV therapy.
Gilead Sciences and Merck announced positive topline results from the phase 3 ISLEND-1 and ISLEND-2 studies evaluating a once-weekly oral combination of islatravir and lenacapavir in adults with virologically suppressed HIV.
In both studies, the regimen met the primary endpoint of maintaining viral suppression through Week 48. The combination was found to be statistically non-inferior to daily treatment regimens, including Biktarvy in ISLEND-1 and a range of standard-of-care antiretroviral therapies in ISLEND-2.
The investigational regimen combines Merck's islatravir, a next-generation nucleoside analog, with Gilead's lenacapavir, a first-in-class capsid inhibitor that targets HIV at multiple stages of its lifecycle. The companies said the pharmacokinetic properties of both agents support once-weekly oral dosing.
“Long-acting oral therapies represent a new wave of transformational innovation in HIV drug development, with the potential to reshape the landscape of care,” Jared Baeten, MD, PhD, senior vice president, Clinical Development, Virology Therapeutic Area Head, Gilead Sciences, said in a statement.
“Innovative oral HIV treatment options that allow for less frequent dosing may make a meaningful difference in the lives of people living with the virus, potentially offering more flexibility and discretion,” Baeten added.
Amy Colson, MD, MPH, discusses data around the combination therapy showing durable virologic suppression, low resistance risk, and favorable safety.
Read here: Once-Weekly Oral Islatravir Plus Lenacapavir Maintains HIV Suppression Through 48 Weeks
The companies noted that less frequent dosing could help address individual preferences among people living with HIV while maintaining viral suppression. The once-weekly tablet is being investigated as a single-pill regimen for adults who are already virologically suppressed on existing therapies.
ISLEND-1 enrolled participants who had maintained viral suppression on Biktarvy for at least six months, while ISLEND-2 included individuals receiving a variety of stable antiretroviral regimens. Both studies are continuing through Week 96 to assess longer-term outcomes.
“These results underscore the shared focus and commitment that we and our collaborators at Gilead have on continuing research to help people living with HIV,” Eliav Barr, MD, senior vice president, head of Global Clinical Development and Chief Medical Officer, Merck Research Laboratories, said in a statement.
“By advancing this investigational novel once-weekly oral regimen of islatravir and lenacapavir, we aim to bring forward a new long-acting oral option that, if approved, would represent the first of its kind with less frequent dosing and further expand options for people living with HIV,” Barr said.
Gilead and Merck said they plan to submit the phase 3 data to regulatory authorities worldwide and present detailed findings at a future scientific meeting. The islatravir/lenacapavir combination remains investigational and has not yet been approved for use.
