Efficacy and Safety of WXSH0208 Tablets in Treatment of Acute Uncomplicated Influenza Infection in Adults: A Multicenter Randomized, Double-Blind, Placebo-Controlled Phase 2 Trial.

Summary

In a multicenter double-blind phase 2 RCT (n=209 ITT-infected), WXSH0208 shortened time to RT-qPCR negativity by ~48–49 hours versus 95.6 hours on placebo, across dosing regimens, with similar symptom trajectories and acceptable safety. These results validate influenza polymerase targeting in uncomplicated influenza and warrant phase 3 clinical outcome studies.

Key Findings

• Median time to RT-qPCR negativity: ~48–49 h with WXSH0208 vs 95.6 h with placebo (P<.001) across dosing arms.
• No significant difference in time to symptom alleviation among groups.
• Treatment-emergent adverse events were mostly mild/moderate and comparable or lower than placebo (48.3–51.7% vs 58.3%).

Clinical Implications

Although symptom relief was not accelerated, accelerated viral clearance with acceptable safety supports further trials to assess clinical endpoints (symptom duration, complications, transmission) and positioning relative to neuraminidase inhibitors and baloxavir.

Limitations

• Clinical symptom endpoints were not improved; study not powered for complications or transmission outcomes.
• Short follow-up focused on early virologic kinetics; resistance emergence was not reported.

Future Directions

Proceed to phase 3 trials emphasizing clinical endpoints, resistance monitoring, high-risk subgroups, and head-to-head comparisons versus standard antivirals.