Traws Pharma shares surge 22.27% premarket as positive interim data shows ratutrelvir's favorable profile versus Paxlovid with fewer adverse events and no viral rebounds.

Traws Pharma surged 22.27% in premarket trading following the release of positive interim clinical data for its experimental antiviral drug ratutrelvir in a Phase 2 trial. The study showed ratutrelvir, a ritonavir-free Mpro protease inhibitor, demonstrated a favorable tolerability profile with fewer adverse events (e.g., 7.6% mild dyspepsia vs. 30% in the Paxlovid comparator group) and no viral rebounds, compared to one rebound in the Paxlovid arm. The drug also showed activity in 16.2% of patients ineligible for Paxlovid due to contraindications or drug interactions, addressing a significant unmet medical need. The interim results, though preliminary, suggest ratutrelvir could offer a differentiated treatment option for both acute COVID-19 and long-COVID prevention, with final data expected in January 2026. The news aligns with Traws Pharma’s strategic focus on developing next-generation antiviral therapies for respiratory diseases.