The US Food and Drug Administration (FDA) approved pritelivir (Hovilpri) tablets for immunocompromised adults with mucocutaneous herpes simplex virus (HSV) lesions that do not respond to acyclovir, valacyclovir, or famciclovir.
The approval was supported by part C of the randomized, open-label, comparator-controlled superiority phase 3 PRIOH-1 trial (NCT03073967) evaluating pritelivir in immunocompromised adult patients with mucocutaneous HSV infections unresponsive to standard antiviral treatment.
Researchers randomly assigned 101 participants to receive pritelivir or the researcher's choice of available treatments. Therapy continued for up to 28 days or until all mucocutaneous lesions healed. Those whose lesions were improving but had not completely healed after 28 days could continue treatment for up to 42 days.
The primary efficacy endpoint was the proportion of participants with all lesions healed during the treatment period up to 28 days. By day 28, complete healing occurred in 63% of pritelivir recipients compared with 34% of those receiving comparator treatments.
Participants had a range of immunosuppressive conditions, including hematologic malignancies or disorders, hematopoietic stem cell transplantation, human immunodeficiency virus infection, autoimmune or inflammatory diseases, nonhematologic malignancies, and solid-organ transplantation. Some participants had more than 1 underlying condition.
The FDA noted HSV-1 and HSV-2 infections commonly cause painful mucocutaneous lesions, including fluid-filled blisters that rupture and crust over. Lesions may affect the skin or mucosal surfaces of the lips, nostrils, eyes, and genitals. HSV infection is lifelong, with periods of viral dormancy and reactivation. Viral shedding may also occur without symptoms.
According to the FDA, immunocompromised patients can experience more frequent and severe HSV outbreaks. Existing antiviral treatments may be less effective because of viral resistance, while adverse effects can limit treatment tolerability.
Headache was the most commonly reported adverse reaction with pritelivir. The FDA advised clinicians to consult the prescribing information regarding certain drug interactions.
The FDA granted pritelivir priority review for this indication.
Source: FDA, ClinicalTrials.gov
