Onradivir as good as oseltamivir for acute, uncomplicated flu

In the treatment of adults with acute, uncomplicated influenza infections, onradivir appears to provide similar curative efficacy as oseltamivir while having an acceptable safety profile, as shown in a phase III study.

The study included adult patients with influenza A virus who presented with a fever (≥38.0°C) and at least one moderate systemic and one moderate respiratory symptom within 48 h of symptom onset. These patients were randomly assigned to receive one of the following treatments: 600-mg oral onradivir tablets once daily, 75-mg oral oseltamivir phosphate capsules twice daily, or oral placebo. Treatment lasted 5 days.

Time to alleviation of symptoms was assessed as the primary outcome in the intention-to-treat infection (ITTI) population (ie, all participants who were randomly assigned and tested positive for influenza A virus). The frequency and severity of adverse events (AEs) were also evaluated in all participants who received treatment at least once.

A total of 750 participants met the inclusion criteria and were randomly assigned to a treatment group. However, 48 had negative influenza A virus tests, leaving 702 (mean age 28.1 years, 59 percent men) in the ITTI population (n=349 in the onradivir group, n=177 in the oseltamivir group, and n=176 in the placebo group). Mean viral load at baseline was 5.15 log₁₀ copies per mL and was similar across the treatment groups.

The median time to alleviation of symptoms in the onradivir group was comparable with that in the oseltamivir group (38.83 vs 42.17 h; hazard ratio [HR], 1.12, 95 percent confidence interval [CI], 0.93–1.35; p=0.092) but significantly shorter than that in the placebo group (38.83 vs 63.35 h; HR, 1.53, 95 percent CI, 1.27–1.85; p<0.0001).

AEs occurred in 67 percent of participants in the onradivir group, 47 percent in the oseltamivir group, and 55 percent in the placebo group. Notably, diarrhoea was more common in the onradivir group than in the oseltamivir and placebo groups (49 percent vs 15 percent and 23 percent, respectively), but most cases were grade 1 or 2 in severity and resolved without medication within a median of 2 days.