Traws Pharma is advancing its antiviral programs for COVID-19 and influenza, with Phase 1 data suggesting potential best-in-class treatments. The company's lead candidates, ratutrelvir for COVID-19 and tivoxavir marboxil for influenza, have shown promising pharmacokinetic profiles that support convenient dosing regimens and reduced risk of adverse effects. These advancements pave the way for Phase 2 clinical trials slated to begin in 2025.
Ratutrelvir: A Novel COVID-19 Monotherapy
Ratutrelvir, an oral Mpro/3CL protease inhibitor, is being developed as a once-a-day, single-dose, 10-day antiviral regimen for COVID-19. Unlike existing treatments, ratutrelvir does not require co-administration with CYP inhibitors like ritonavir, which can lead to drug-drug interactions and severe side effects. Phase 1 data from a healthy volunteer study demonstrated consistent plasma drug levels within the predicted therapeutic window, with no treatment-related adverse events.
"Based on our recent Phase 1 pharmacokinetic results, we believe that ratutrelvir has the potential to be used as a monotherapy to treat COVID, without ritonavir, with a lower likelihood of clinical rebound," said Werner Cautreels, PhD, Chief Executive Officer of Traws Pharma. The study also indicated that ratutrelvir achieved plasma concentrations consistently above the EC90 against a panel of SARS-CoV-2 viruses. Preclinical testing in animal models further revealed higher levels of ratutrelvir in the lung compared to plasma, supporting its potential as an effective antiviral therapy.
Tivoxavir Marboxil: Single-Dose Flu Treatment
Tivoxavir marboxil, an oral influenza cap-dependent endonuclease inhibitor, is being developed as a one-time treatment for flu, including pandemic and avian flu. Phase 1 data demonstrated good overall tolerability and a pharmacokinetic profile that supports its potential use as a single-dose treatment. The study showed that a single dose of tivoxavir maintained plasma drug levels above the EC90 for more than five days. Preclinical studies have also shown that tivoxavir has broad activity against drug-resistant viruses and highly pathogenic strains, with a single dose demonstrating over 15-fold higher accumulation in the lung compared to plasma.
"Recent Phase 1 pharmacokinetic data suggest that tivoxavir marboxil could be a single-dose treatment for influenza, including potential pandemic settings such as avian flu," added Dr. Cautreels. This characteristic supports its potential as a differentiated, best-in-class treatment for community-acquired influenza and for use in case of an avian flu outbreak or pandemic, with further potential to prevent virus spread in households and congregant settings.
Advancing to Phase 2
Traws Pharma is poised to initiate Phase 2 clinical proof-of-concept studies for both ratutrelvir and tivoxavir marboxil in community-acquired settings in 2025. These studies will further evaluate the efficacy and safety of these novel antiviral agents.
Financial Update
As of September 30, 2024, Traws Pharma reported cash, cash equivalents, and short-term investments of approximately $5.4 million. Research and development expenses for the three months ended September 30, 2024, totaled $5.1 million, compared to $2.5 million for the comparable period in 2023. The net loss for the three months ended September 30, 2024, was $8.5 million, or $8.81 per basic and diluted common share.
