Traws Pharma Reports Positive Phase 1 Results for COVID Oral Mpro Inhibitor Ratutrelvir

Traws Pharma, Inc., a clinical-stage biopharmaceutical company, has announced promising Phase 1 results for its COVID-19 candidate, ratutrelvir. This oral inhibitor of the SARS-CoV-2 Main protease (Mpro) demonstrated no treatment-related adverse events over a 10-day administration period. Notably, it achieved consistent plasma drug levels within the predicted therapeutic window without the need for ritonavir co-administration, which can cause severe side effects due to drug-drug interactions.

Dr. Werner Cautreels, CEO of Traws Pharma, expressed optimism about ratutrelvir's potential as a potent, once-daily, 10-day antiviral therapy for COVID-19. Unlike Paxlovid™, which requires ritonavir, ratutrelvir’s ritonavir-free regimen could simplify treatment and reduce the burden, especially for patients with underlying health conditions. The company is preparing for a Phase 2a study, expected to commence in the first half of 2025.

Dr. Robert R. Redfield, Chief Medical Officer of Traws Pharma and former CDC Director, highlighted the ongoing need for effective COVID-19 therapies. Despite existing antiviral treatments, COVID-19 remained a significant cause of mortality in the U.S. in 2023, with around 50,000 deaths. Redfield emphasized the importance of new treatments that are easy to administer and effective against resistant viruses, especially for high-risk groups like older adults with conditions such as heart disease, kidney disease, and chronic lung disease.

Chief Scientific Officer Dr. C. David Pauza noted that preclinical studies presented at the 2024 International Conference on Antiviral Research (ICAR2024) showed ratutrelvir's differentiated activity against drug-resistant viruses. Additionally, ratutrelvir achieved higher lung levels than plasma levels in animal studies, suggesting a lower likelihood of clinical rebound.

The Phase 1 trial, conducted in Australia, was a randomized, double-blind, placebo-controlled study evaluating the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of single and multiple ascending doses (SAD and MAD) of ratutrelvir in 56 healthy adult volunteers. The study revealed no treatment-related adverse events up to the highest dose tested. Once-daily administration maintained plasma drug levels within the therapeutic window, and preclinical data showed ratutrelvir's effectiveness against various SARS-CoV-2 variants.

Ratutrelvir, also known as 83-0060 or TRX-01, is designed to inhibit the SARS-CoV-2 Main protease. It has shown in vitro activity against the original strain and variants such as delta and omicron. Preclinical studies indicate that ratutrelvir does not require co-administration with ritonavir, which poses risks for drug-drug interactions and severe side effects. The drug's pharmacokinetic profile, demonstrated in Phase 1 studies, supports a once-daily treatment regimen and suggests a reduced risk of clinical rebound.

Traws Pharma is a clinical-stage biopharmaceutical company focused on developing oral therapies for respiratory viral diseases and cancer. Their respiratory viral disease program includes tivoxavir marboxil for influenza and avian flu, and ratutrelvir for COVID-19. The cancer program involves developing multi-kinase inhibitors like narazaciclib and rigosertib.

The company employs advanced drug development technology to create solutions for unmet medical needs, prioritizing product safety and patient care, especially for vulnerable populations.