Nirmatrelvir

Ongoing clinical results with ratutrelvir confirm a differentiated profile versus PAXLOVID® with fewer adverse events, no viral rebounds to date and faster time to sustained symptom resolution; results recapitulated in PAXLOVID®-ineligible patients, representing a significant population with few effective treatment options Compressed tablets of tivoxavir marboxil predicted to provide 28-day protection from influenza against wide range of seasonal and pandemic-potential variants Human influenza prophylaxis challenge study time slot secured for June 2026 NEWTOWN, Pa., Jan. 26, 2026 (GLOBE NEWSWIRE) -- Traws Pharma, Inc. (NASDAQ: TRAW) (“Traws Pharma”, “Traws” or “the Company”), a clinical-stage biopharmaceutical company developing novel therapies to target critical threats to human health from respiratory viral diseases, today announced the completion of enrollment in its ongoing 90-patient, open-label Phase 2 study of ratutrelvir, an investigational oral, ritonavir-free Mpro/3CL protease inhibitor, versus PAXLOVID®, in patients with mild-to-moderate COVID-19, together with a single arm in PAXLOVID®-ineligible subjects. Patients ineligible to receive PAXLOVID® are frequently at elevated risk for severe disease and require suitable, safe and effective treatment options. Ratutrelvir has the potential to address this gap in care and may be a valuable therapeutic option. The Company also provided an update on the progress of the tivoxavir marboxil program for influenza. Ratutrelvir Update The study, designed as an active-controlled comparator trial versus PAXLOVID® (nirmatrelvir/ritonavir), evaluated patient-reported symptom outcomes, safety, and real-world usability. A separate treatment arm was comprised of patients ineligible for ritonavir-boosted regimens due to contraindications or clinically significant drug–drug interactions. Patients in the ratutrelvir arm received ratutrelvir 600 mg orally, once daily for 10 days, while patients in the comparator arm received oral PAXLOVID®, administered as nirmatrelvir 300 mg twice daily plus 100 mg ritonavir twice daily for 5 days, consistent with approved prescribing information. “From a clinical perspective, the ongoing data analysis confirms previous reports that ratutrelvir may provide a meaningful benefit across a broader range of patients, including those who are unable to receive ritonavir-boosted therapy,” commented Robert R. Redfield, MD, Chief Medical Officer of Traws Pharma. “The favorable tolerability profile, together with a shortened time to symptom resolution and the absence of viral rebound events in ratutrelvir-treated patients, encourages and supports the continued clinical evaluation of ratutrelvir in both acute COVID-19 and in studies designed to better understand its potential impact on longer-term outcomes.” “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),” continued Dr. Redfield. “By enabling earlier and potentially more complete viral clearance, without the limitations associated with ritonavir boosting, ratutrelvir may offer a differentiated approach to both acute COVID-19 treatment and prevention of longer-term complications.” Tivoxavir Marboxil Update The Company additionally announced that it is progressing an additional indication for tivoxavir marboxil (TXM), a potential best in class CAP-dependent endonuclease inhibitor, as a single monthly oral tablet for the prophylactic treatment of seasonal influenza. “In prior Phase 1 studies in healthy volunteers, an unformulated powder-in-capsule formulation provided blood levels exceeding 3X the EC50 against a basket of common seasonal influenza variants for up to 22 days after drug administration. A new compressed tablet formulation may provide 28 day coverage, enabling a once-a-month prophylactic treatment,” commented C. David Pauza, PhD, Chief Science Officer of Traws Pharma. “Once a planned bridging healthy volunteer study has confirmed the extended exposure, we will progress TXM into a seasonal influenza virus prophylaxis Challenge Study in June 2026 at hVIVO, the pre-eminent CRO for such studies. Positive results will enable progression into registration studies,” continued Dr. Pauza. “Collectively, the advancement of our antiviral portfolio provides a number of significant value inflection points and could provide needed treatment and prevention options for clinically important viral diseases,” commented Iain Dukes, MA, DPhil, Chief Executive Officer of Traws Pharma. About Ratutrelvir Ratutrelvir is an investigational oral, small molecule Mpro (3CL protease) inhibitor designed to be a broadly acting treatment for SARS-CoV-2/COVID-19 that is used without ritonavir. It has demonstrated in vitro activity against a range of virus strains. Preclinical and Phase 1 studies show that ratutrelvir does not require co-administration with a metabolic inhibitor, such as ritonavir, which could avoid ritonavir-associated drug-drug interactions1, and potentially enable wider patient use. Phase 1 data also show that ratutrelvir’s pharmacokinetic (PK) profile demonstrated maintenance of target blood plasma levels approximately 13 times above the EC50 using the target Phase 2 dosing regimen of 600 mg/day for ten days, which may also reduce the likelihood of clinical rebound and, consequently, reduce the risk for Long COVID2. Industry data indicate that COVID treatment represents a potential multi-billion dollar market opportunity3. About Tivoxavir Marboxil Tivoxavir marboxil (TXM) is an investigational oral, small molecule CAP-dependent endonuclease inhibitor designed to be administered as a single-dose for the treatment of bird flu and the treatment or prophylaxis of seasonal influenza. It has shown potent in vitro activity against a range of influenza strains in preclinical studies, including a human isolate of the highly pathogenic avian flu H5N1 (bird flu). Consistent, positive preclinical data from three animal species indicate that a single dose of TXM demonstrated a therapeutic effect against H5N1 bird flu. Seasonal influenza represents an estimated multi-billion dollar antiviral market opportunity, largely driven by global health organizations, practice guidelines and government tenders and inclusion in drug stock piling initiatives4,5, with upside potential from potential pandemic flu outbreaks including H5N1 bird flu. We believe that these data support further development of TXM as a treatment for bird flu. Source information https://ascpt.onlinelibrary.wiley.com/doi/pdf/10.1002/cpt.2646Carly Herbert et al. (2025) Clinical Infectious Diseases. https://pubmed.ncbi.nlm.nih.gov/39692474/Pfizer Inc. annual report on Form 10-K for the fiscal year ended December 31, 2024, filed with the U.S. Securities and Exchange Commission on February 27, 2025Per link TRAW data on file Third-party products mentioned herein are the trademarks of their respective owners. About Traws Pharma, Inc. Traws Pharma is a clinical stage biopharmaceutical company dedicated to developing novel therapies to target critical threats to human health in respiratory viral diseases. Traws integrates antiviral drug development, medical intelligence and regulatory strategy to meet real world challenges in the treatment of viral diseases. We are advancing novel investigational oral small molecule antiviral agents that have potent activity against difficult to treat or resistant virus strains that threaten human health: COVID-19/Long COVID and bird flu and seasonal influenza. Ratutrelvir is in development as a ritonavir-independent COVID-19 treatment, targeting the Main protease (Mpro or 3CL protease). Tivoxavir marboxil is in development as a single dose treatment for bird flu and seasonal influenza, targeting the influenza cap-dependent endonuclease (CEN). Traws is actively seeking development and commercialization partners for its legacy clinical oncology programs, rigosertib and narazaciclib. More details can be found on Traws’ website at https://www.ir.trawspharma.com/partnering. For more information, please visit www.trawspharma.com and follow us on LinkedIn. 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, market size, benefits, effectiveness, safety, and the clinical and regulatory plans for ratutrelvir and tivoxavir marboxil, as well as plans for its legacy programs. 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 outcome of Traws’ IND filing with the FDA; the potential efficacy and tolerability of ratutrelvir for the treatment of COVID-19, including the potential to reduce the risk of COVID rebound and Long COVID; the success and timing of Traws’ clinical trials, including when Traws will report results of its studies of tivoxavir marboxil; the potential efficacy of tivoxavir marboxil to provide 28-day coverage against seasonal influenza variants; the potential for ratutrelvir or tivoxavir marboxil to gain market acceptance, if and when regulatory approval is obtained, or to become the new standard of care; Traws’ interactions with the FDA, BARDA and similar foreign regulators; collaborations; market conditions; regulatory requirements and pathways for approval; the ongoing need for improved therapy to reduce the frequency of clinical rebound and the concomitant risk for Long COVID; the extent of the spread and threat of the bird flu; the Company’s cash projections; Traws’ ability to raise additional capital when needed; 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: Charles ParkerTraws Pharma, Inc.cparker@trawspharma.com www.trawspharma.com Investor Contact: John Fraunces LifeSci Advisors, LLC917-355-2395jfraunces@lifesciadvisors.com

科研讲座 翠亨大师讲坛 1月13日，中科中山药物创新研究院举办第六十六期“翠亨大师讲坛”。广州医科大学附属第一医院广州呼吸健康研究院副院长杨子峰教授应邀作题为“呼吸药物评价与转化平台”的学术报告。本次报告由常务副院长丁侃主持。 杨子峰研究团队依托国家呼吸系统疾病临床医学研究中心的权威平台与技术优势，构建了从基础研究到临床转化的完整研发链条，有力推动了创新药物的研发进程。团队通过计算和分子对接分析，基于VX-787结构，开创性地合成了具有全新骨架的“昂拉地韦”。 临床前研究表明，昂拉地韦在体外对多种甲型流感病毒株展现出极高的抗病毒活性（EC₅₀ 0.012–0.063 nM），显著优于对照药物VX-787及玛巴洛沙韦。延迟给药小鼠模型表明其可有效控制病毒载量并促进体重恢复。Ⅲ期临床试验证实其能显著缩短症状缓解时间并加速病毒清除。针对新冠病毒，团队聚焦3CLpro蛋白酶靶点，基于辉瑞PF07321332需联用利托那韦的缺陷，通过结构优化合作研发出可单药使用的候选分子RAY1216，实现了无需联用利托那韦的单药给药方案。目前该药已在中国澳门正式上市。 杨子峰作报告 讲座在热烈的交流中结束。与会师生围绕呼吸道疾病防治与新药研发展开讨论，杨子峰教授团队的突破性成果，为我国中西医结合应对新发突发传染病与重大传染病提供了重要示范。 活动合照 本期嘉宾介绍 杨子峰，二级教授、教育部长江学者（抗疫），国家高层次人才、广东省特支计划杰出人才。现任广州医科大学附属第一医院广州呼吸健康研究院副院长、广州医科大学呼吸疾病全国重点实验室副主任、广州国家实验室特聘研究员、澳门科技大学特聘教授等职务。主持多项国家自然科学基金和国家重点研发计划，已在Science、New England、Lancet和Nature子刊等国际高水平期刊发表论文百余篇。获得授权的国家、国际发明专利10余项。其成果荣获国家科技进步创新团队奖、广东省科技进步特等及一等奖等多项奖励。 供稿部门 | 丁侃课题组