FDA approved an oral pill for herpes lesions that resist standard drugs in people with weak immune systems

On October 9, 2026, the FDA approved Hovilpri (pritelivir) tablets for adults with weakened immune systems who have mucocutaneous herpes simplex lesions that did not respond to acyclovir, valacyclovir, or famciclovir. Those sores can form on skin or mucosal surfaces, including the lips, nostrils, eyes, and genitals. The agency's page says that once a person has HSV, the infection cannot be cured. The approval covers only this narrow group whose lesions did not respond to those three drugs. It is not a treatment for the general public, and it is not a cure.

The evidence is a randomized, open-label trial called PRIOH-1, with 101 immunocompromised adults. Participants could have a blood cancer, a stem-cell or organ transplant, HIV, an autoimmune disease, or another immunosuppressive condition. They received Hovilpri or the investigator's choice of available treatments for up to 28 days, extended to 42 days if lesions were improving but not healed. By day 28, all lesions had healed in 63 percent of people on Hovilpri, compared with 34 percent on the other treatments. The trial is modest in size, and because it was open-label, patients and doctors knew which drug was being used. The most common side effect was headache. The label also warns about certain drug interactions. This is one more option for a small group of patients, and follow-up in the FDA summary stops at lesion healing.