Traws Pharma Inc. (TRAW) released interim Phase 2 data Wednesday that suggests its experimental COVID-19 treatment might stand toe-to-toe with the established champion. The company's ratutrelvir—an oral antiviral that doesn't need ritonavir boosting—performed comparably to Pfizer Inc.'s (PFE) Paxlovid in relieving symptoms among patients with mild-to-moderate COVID-19.

Here's what makes this interesting: ratutrelvir is an Mpro/3CL protease inhibitor that works without ritonavir, the boosting agent that comes packaged with Paxlovid's nirmatrelvir. That matters because ritonavir causes significant drug interactions, creating a whole category of patients who simply can't take Paxlovid safely.

The Trial Design and What They Found

This was an open-label, randomized study designed specifically to compare ratutrelvir against Paxlovid in real-world conditions. The trial evaluated patient-reported symptom outcomes, safety profiles, and practical usability—the stuff that actually matters when people are sick at home.

The interim analysis included 37 patients: 25 received ratutrelvir (600 mg once daily for 10 days) and 12 got Paxlovid (nirmatrelvir 300 mg plus ritonavir 100 mg twice daily for 5 days, per standard prescribing guidelines).

Time-to-sustained symptom alleviation was numerically comparable between the two groups. The study defined "sustained alleviation" as self-reported relief from all COVID-19 symptoms lasting four consecutive days. Worth noting: not all patients had completed the full 28-day observation period at analysis time, and the company performed no formal statistical comparisons, making these findings descriptive rather than inferential.

The Rebound Question

Viral rebound has been a persistent concern with short-course COVID treatments. In this interim data, ratutrelvir showed zero rebound events to date. Meanwhile, one Paxlovid patient (8.3% of that cohort) experienced rebound shortly after finishing the standard 5-day regimen.

It's early data with small numbers, but the extended 10-day dosing schedule for ratutrelvir might be relevant here.

Filling a Treatment Gap

Perhaps the most commercially interesting finding: six patients (24% of the ratutrelvir group) couldn't have taken Paxlovid at all due to contraindications or significant drug-drug interaction risks. These patients showed symptom improvement dynamics consistent with the broader ratutrelvir cohort, suggesting the drug could serve a real unmet need.

Ratutrelvir was well tolerated overall, with fewer reported adverse events compared to the Paxlovid group.

"The combination of early and sustained symptom improvement, extended dosing duration, absence of viral rebound observed to date, and favorable tolerability supports the strategic hypothesis that ratutrelvir may have utility in reducing post-acute sequelae of SARS-CoV-2 infection (Long COVID)," commented Robert Redfield, Chief Medical Officer at Traws Pharma.

Price Action: TRAW stock declined 2.27% to $2.15 in premarket trading Wednesday.