Clinical Scorecard: FDA approves pritelivir for refractory HSV lesions

At a Glance

Key Highlights

• The FDA approved pritelivir (Hovilpri) tablets for immunocompromised adults with mucocutaneous HSV lesions unresponsive to acyclovir, valacyclovir, or famciclovir.
• Approval was supported by part C of the randomized, open-label, comparator-controlled phase 3 PRIOH-1 trial.
• Among 101 participants, complete lesion healing by day 28 occurred in 63% receiving pritelivir and 34% receiving comparator treatments.
• Treatment continued for up to 28 days, with extension to 42 days permitted for participants whose lesions were improving but not fully healed.
• Headache was the most commonly reported adverse reaction; the FDA advised consulting prescribing information for certain drug interactions.

Guideline-Based Recommendations

Diagnosis

• The approved indication applies to mucocutaneous HSV lesions in immunocompromised adults that do not respond to acyclovir, valacyclovir, or famciclovir.

Management

• Pritelivir tablets are FDA-approved for the specified refractory HSV indication.
• In PRIOH-1, treatment continued for up to 28 days or until all mucocutaneous lesions healed; participants with improving but unhealed lesions could continue for up to 42 days.

Monitoring & Follow-up

• Assess lesion healing during treatment; the trial's primary efficacy endpoint was complete healing during treatment through day 28.
• Consult pritelivir prescribing information regarding certain drug interactions.

Risks

• Headache was the most commonly reported adverse reaction with pritelivir.
• The FDA noted that immunocompromised patients can have more frequent and severe HSV outbreaks, and viral resistance or adverse effects may limit existing antiviral treatment.

Patient & Prescribing Data

The PRIOH-1 trial enrolled immunocompromised adults with mucocutaneous HSV infections unresponsive to standard antiviral treatment. Underlying conditions included hematologic malignancies or disorders, hematopoietic stem cell transplantation, HIV infection, autoimmune or inflammatory diseases, nonhematologic malignancies, and solid-organ transplantation; some participants had more than one condition.

In the randomized trial, 101 participants received pritelivir or the researcher's choice of available treatments. Complete healing by day 28 occurred in 63% of pritelivir recipients versus 34% of comparator recipients.

Clinical Best Practices

• Use the approved indication for immunocompromised adults whose mucocutaneous HSV lesions do not respond to acyclovir, valacyclovir, or famciclovir.
• Follow the prescribing information for dosing and drug-interaction guidance.
• Evaluate lesion healing during treatment, noting that the trial allowed treatment extension to 42 days when lesions were improving but not completely healed after 28 days.

Related Resources & Content

• FDA
• ClinicalTrials.gov: PRIOH-1 (NCT03073967)