Oral Pritelivir Lowers Hospitalization in Treatment-Resistant HSV
In the phase 3 PRIOH-1 trial, oral pritelivir led to full lesion healing in 62.7% of immunocompromised patients with refractory HSV by day 28, compared with 34.0% for investigator-selected therapy. Hospitalization occurred in 29.4% of pritelivir recipients versus 76% in the comparator group, and fewer drug-related adverse events were reported. Pritelivir remains investigational; foscarnet is still the only FDA-approved option for acyclovir-refractory HSV.
Pritelivir targets the HSV helicase-primase complex rather than relying on viral thymidine kinase for activation. Laboratory testing indicates it remains active against isolates resistant to nucleoside analogs and foscarnet.
In the phase 3 PRIOH-1 study, 62.7% of immunocompromised patients with refractory HSV had complete lesion healing by day 28 with oral pritelivir, versus 34.0% on investigator-chosen therapy. Hospitalization was 29.4% versus 76%, and fewer drug-related adverse events occurred. Pritelivir is still investigational; foscarnet is the sole FDA-approved option for acyclovir-refractory HSV.
If approved, an oral option could reduce need for intravenous foscarnet and hospital stays, potentially easing treatment burden for immunocompromised patients and their caregivers. It may also lessen demand on inpatient beds and infusion services, though access, cost, and long-term safety would need scrutiny. For now, foscarnet remains standard approved therapy, so impact depends on regulatory review and real-world data.