FDA Clears Oral Pritelivir for Stubborn Herpes Outbreaks in Immunocompromised Adults

The US FDA has signed off on oral pritelivir, marketed as Hovilpri, for mucocutaneous lesions caused by herpes simplex virus in immunocompromised adults who haven't responded adequately to other antivirals. That covers a group that frequently runs out of options: patients whose HSV is resistant to existing drugs or who can't tolerate their side effects, according to Medical Dialogues.

The evidence comes from the randomized, open-label, comparator-controlled PRIOH-1 Phase 3 trial, Part C (NCT 03073967). Researchers enrolled 101 immunocompromised adults who had failed treatment with acyclovir, valacyclovir or famciclovir. Participants took either Hovilpri or an investigator's choice of available therapies for up to 28 days, extended to 42 days if lesions were improving but not fully healed.

The primary endpoint was the share of participants with every lesion healed during the treatment window. By day 28, 63% of Hovilpri patients had fully healed, compared with 34% of those on the comparator treatments. The trial population spanned a wide mix of immunosuppressive conditions, including hematologic malignancy or disorder, hematopoietic stem-cell transplantation, HIV, autoimmune or inflammatory diseases, non-hematologic cancers and solid-organ transplantation.

Headache was the most common adverse reaction reported. The prescribing information flags certain drug interactions with Hovilpri. HSV-1 and HSV-2 are common infections that cause painful, fluid-filled blisters which break open and crust over; once someone has the virus it can't be cured, and it can lie dormant, reactivate into outbreaks, or spread without symptoms.