Traws Pharma, Inc. announced that it completed dosing in the first cohort of the first-in-human Phase 1 study to evaluate travatrelvir (TRX01), an orally-available protease inhibitor, in development for treatment of COVID19. There have been no safety observations reported. Travatrelvir was designed as an inhibitor of the SARS-CoV-2 Mpro (3CL protease).

It has demonstrated in vitro activity against the original strain of the virus as well as the delta and omicron variants and is more active than nirmatrelvir (Pfizer?s Mpro inhibitor) in preclinical studies. Also in preclinical studies, travatrelvir did not require co-administration with a human cytochrome P450 (CYP) inhibitor, such as ritonavir, and so it is expected to avoid associated drug:drug interactions, potentially permitting wider patient use. The drug candidate?s pharmacokinetic (PK) profile may enable a once daily, 10-day treatment regimen to reduce the likelihood of viral rebound.

GLP toxicology studies did not identify adverse events (AEs) in animals at the doses being studied in the Phase 1 clinical trial. The Phase 1 study will evaluate single and multiple ascending doses of travatrelvir in a double-blinded, placebo-controlled study to assess safety, tolerability, and pharmacokinetics. Subjects will be randomized 3:1 in five fasted and one fed single ascending dosing (SAD) cohorts and two multiple ascending dosing (MAD) cohorts.

Topline data from the study, which is being conducted in Australia, and the initiation of an international Phase 2 study in subjects with moderate to severe COVID19, are expected to take place in H2 2024.