The U.S. FDA has placed a clinical hold on Gilead’s HIV treatment trials of GS-1720 (an investigational integrase strand transfer inhibitor) and GS-4182 (an investigational capsid inhibitor), due to safety concerns.
The hold is due to the identification of a safety signal of decreases in a type of white blood cell, CD4+T-cell, and absolute lymphocyte counts in a subset of participants receiving the combination of GS-1720 and GS-4182.
In total, two phase 2/3 trials — WONDERS-1 and WONDERS-2 — are included in the hold, as well as three additional phase 1 trials of either agent and/or their combinations.
GS-4182 is an experimental pill version of the company's HIV drug lenacapavir, approved under the brand name Sunlenca in 2022, while GS-1720 is a once-weekly integrase strand transfer inhibitor in development for treatment of HIV.
Gilead says it will “investigate and pursue the potential of both agents and are committed to working with regulatory authorities to resolve the issues underlying the clinical hold.”