The U.S. FDA has approved Gilead’s Sunlenca (lenacapavir), a new type of antiretroviral medication for adult patients whose HIV infections cannot be successfully treated with other available treatments due to resistance, intolerance or safety considerations.

Sunlenca is the first of a new class of drugs called capsid inhibitors to be FDA-approved for treating HIV-1. Sunlenca works by blocking the HIV virus’ protein shell (the capsid), thereby interfering with multiple essential steps of the viral life cycle.  The drug’s starting dose is given as oral tablets and subcutaneous injections, followed by maintenance injections every six months; Sunlenca is given in combination with other antiretrovirals.

The FDA had rejected Gilead’s NDA for Sunlenca back in March. In the complete response letter, the FDA said its decision to reject the candidate was due to CMC issues with the glass vials the drug was intended to be distributed in. Specifically, the agency raised questions about vials made of borosilicate glass and their compatibility with lenacapavir solution. The European Commission approved the drug a few months later in August. 

The FDA approval for Sunlenca is supported by data from the phase 2/3 CAPELLA trial, which evaluated lenacapavir in combination with an optimized background regimen in people with multi-drug resistant HIV-1 who are heavily treatment-experienced. CAPELLA participants had undergone previous treatment with a median of nine antiretroviral medications. According to Gilead, in this patient population with a significant unmet medical needs, 83% of participants randomly allocated to receive lenacapavir in addition to an optimized background regimen achieved an undetectable viral load at week 52.

Despite the significant advances in ARV therapy, there remain numerous critical and pressing unmet needs for people living with HIV. This is particularly true for individuals who are heavily treatment-experienced and are unable to maintain virologic suppression.