Traws Pharma Inc.

DOVER, Del., Oct. 22, 2025 /PRNewswire/ -- Expert Systems Inc., a leading life sciences accelerator, announced its continued support for Traws Pharma (NASDAQ: TRAW) as the company initiates Phase 2 clinical studies of Ratutrelvir (TRX01), a next-generation oral antiviral designed to treat newly diagnosed COVID-19 patients.

Expert Systems' predictive pharmacology and AI-driven molecular modeling played a central role in Ratutrelvir's differentiation—optimizing pharmacokinetics, safety, and potency profiles to ensure broad clinical applicability across both therapeutic and preventive settings.

Ratutrelvir (TRX01) demonstrates broad-spectrum in vitro activity against a range of SARS-CoV-2 virus strains and maintains exceptional potency profiles without requiring ritonavir co-administration. Its ritonavir-independent formulation eliminates the need for metabolic boosting, avoiding the ritonavir-associated drug-drug interactions that currently exclude approximately 20% of COVID patients from protease inhibitor treatment.

In Phase 1 multiple ascending dose (MAD) studies, a daily oral 600 mg regimen sustained plasma concentrations ~13× above EC₅₀ for the full 10-day course, with trough levels remaining above EC₉₀  - critical for preventing viral rebound. Expert Systems' modeling predicts even higher concentrations in lung tissue versus plasma, enhancing antiviral exposure at the primary infection site..

Following successful completion of Phase 1 safety and PK studies, regulatory approval was granted for Phase 2 initiation in Q3 2025. The Phase 2 program includes:

• A non-inferiority trial versus PAXLOVID® in newly diagnosed COVID-19 patients; and
• A single-arm trial in PAXLOVID®-ineligible populations—an underserved group at greater risk for severe outcomes.

"COVID-19 continues to pose a significant public health threat, particularly among elderly and immunocompromised individuals who often cannot access current standard-of-care options," said Dr. Tudor Oprea, CEO of Expert Systems Inc. "By applying our AI/ML-driven molecular design platform to systematically optimize both potency and pharmacokinetics without ritonavir, we enabled the development of a truly differentiated antiviral. Ratutrelvir's superior 13× EC₅₀, ritonavir-free exposure, for an extended 10-day regimen, and excellent safety profile collectively exemplify precision drug design, targeting not only active infection but also the prevention of viral rebound and Long COVID."

Expert Systems will continue to provide strategic, scientific, and technological support as Ratutrelvir advances through human efficacy studies. This collaboration underscores Expert Systems' capability to apply computational design and predictive pharmacology to de-risk innovation and accelerate clinical translation of best-in-class therapeutics.

About Expert Systems Inc.

Expert Systems Inc. is a life sciences accelerator advancing the next generation of precision therapeutics. Its AI/ML-enabled platform integrates rational drug design, predictive pharmacology, translational modeling, regulatory strategy, and partnering support across the biotech value chain.

With a proven record of creating and scaling multiple Seed and Series A ventures, Expert Systems has supported more than 30 R&D programs funded by institutional investors and strategic partners across North America, Europe, and Australia. By shortening timelines from in silico discovery to first-in-human trials, Expert Systems transforms high-potential science into investable, clinically ready opportunities.

Media Contact:

Bill Farley, CBO

Expert Systems Inc.

bfarley@expertsystems.inc  

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SOURCE Expert Systems, Inc.

Phase I completed in healthy volunteers with pharmacokinetic data supporting dosing for both therapeutic and further development for bird flu prevention

NEWTOWN, Pa., Jan. 23, 2025 /PRNewswire/ -- Traws Pharma, Inc. (NASDAQ: TRAW) ("Traws Pharma", "Traws" or "the Company"), a clinical-stage biopharmaceutical company developing oral small molecule therapies for the treatment of respiratory viral diseases, today announced completion of Phase I clinical studies of its investigational one-dose influenza (flu) therapy, tivoxavir marboxil (tivoxavir), for the treatment or prevention of H5N1 bird flu.

"We believe that our clinical data in healthy volunteers support accelerated development of tivoxavir marboxil in response to the growing threat of bird flu," said Werner Cautreels, PhD, Chief Executive Officer of Traws Pharma.

"The first U.S. death from the bird flu² and the spread into commercial poultry farms highlight a growing threat to public health," said Robert R. Redfield, MD, Chief Medical Officer for Traws Pharma and former Director of the U.S. Centers for Disease Control and Prevention (CDC). "We believe that new antiviral therapies, with proven activity against the H5N1 bird flu, are needed to address this potential threat. Continued circulation of this H5N1 virus in wild birds and mammals, plus spread of the virus from cattle or poultry to agricultural workers, sustains the risk for virus adaptation and human to human transmission.³"

"Topline data from the Phase I study demonstrated safety and tolerability of tivoxavir marboxil in humans at levels of exposure that have demonstrated potent inhibition of H5N1 and informs dose selections for further testing in relevant animal models of bird flu," said C. David Pauza, PhD, Chief Science Officer for Traws Pharma. "The combined clinical and animal model data package will guide our upcoming regulatory meetings as we advance this product and, hopefully, provide an important medical countermeasure against bird flu."

Topline Phase I Results

The Phase I trial was a randomized, double-blind, placebo-controlled study to assess the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of ascending doses of one-time tivoxavir marboxil treatment in healthy, influenza-negative, adult volunteers. 

No significant treatment related adverse events were reported during the Phase I study, which evaluated four dose levels. Preclinical studies showed that tivoxavir marboxil demonstrated potent inhibition of drug-resistant influenza viruses, as well as potent inhibition of highly pathogenic bird flu viruses¹, both in vitro and in vivo.

About Tivoxavir Marboxil

Seasonal influenza represents an estimated multi-billion antiviral market opportunity, largely driven by global health organizations, practice guidelines and government tenders¹, with upside potential from pandemic flu outbreaks. Tivoxavir marboxil was designed as an inhibitor of the highly conserved influenza protein, CAP-dependent endonuclease (CEN). It has demonstrated potent in vitro activity against a range of influenza strains in preclinical studies, including the highly pathogenic avian flu H5N1 (bird flu). Completed and ongoing animal model studies are assessing the impact of a single dose of tivoxavir marboxil on lethal bird flu infection. We believe that these data support further development of tivoxavir marboxil as a one-time treatment for bird flu.

Source information:

1.     TRAWS data on file
2.     https://www.cdc.gov/media/releases/2025/m0106-h5-birdflu-death.html 
3.     http://dx.doi.org/10.15585/mmwr.mm7344a3 

About Traws Pharma, Inc. Antiviral Programs

Traws Pharma is a clinical stage biopharmaceutical company developing potential oral small molecule therapies for the treatment of respiratory viral diseases. The viral respiratory disease program includes two oral, novel, Phase I, potentially best-in-class, small molecule drug candidates: tivoxavir marboxil, in development for flu and pandemic flu, targeting the influenza cap-dependent endonuclease (CEN); and ratutrelvir, in development as a COVID treatment, targeting the Mpro (3CL protease), without the need for co-administration of ritonavir.

Traws is committed to delivering novel compounds for unmet medical needs using state-of-the-art drug development technology. With a commitment to patients in need and vulnerable populations, we aim to build solutions for important medical challenges and alleviate the burden of viral infectious disease. 

Forward-Looking Statements 

Some of the statements in this release are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, Section 21E of the Securities Exchange Act of 1934, as amended, and the Private Securities Litigation Reform Act of 1995, and involve risks and uncertainties including statements regarding the Company, its business and product candidates, including the potential opportunity, benefits and the regulatory plans for tivoxavir marboxil. The Company has attempted to identify forward-looking statements by terminology including "believes", "estimates", "anticipates", "expects", "plans", "intends", "may", "could", "might", "will", "should", "preliminary", "encouraging", "approximately" or other words that convey uncertainty of future events or outcomes. Although Traws believes that the expectations reflected in such forward-looking statements are reasonable as of the date made, expectations may prove to have been materially different from the results expressed or implied by such forward looking statements. These statements are only predictions and involve known and unknown risks, uncertainties, and other factors, including the success and timing of Traws' clinical trials, collaborations, market conditions, regulatory requirements, the extent of the spread and threat of the bird flu, and those discussed under the heading "Risk Factors" in Traws' filings with the U.S. Securities and Exchange Commission (SEC). Any forward-looking statements contained in this release speak only as of its date. Traws undertakes no obligation to update any forward-looking statements contained in this release to reflect events or circumstances occurring after its date or to reflect the occurrence of unanticipated events, except to the extent required by law.

Traws Pharma Contact:

Mark Guerin

Traws Pharma, Inc.

267-759-3680

www.trawspharma.com

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SOURCE Traws Pharma, Inc.