influenza A subtype H1N1 infection

Phase 2 interim data for ARCT-032 (CF) & ARCT-810 (OTCD) on track for Q2 2025 Meiji Seika Pharma and ARCALIS received MHLW approval for commercial manufacturing of KOSTAIVE® Meiji Seika Pharma Submitted Application for Two-Dose Vial of KOSTAIVE® KOSTAIVE® U.S. BLA filing anticipated 2025 Investor conference call at 4:30 p.m. ET today SAN DIEGO --(BUSINESS WIRE)--Mar. 6, 2025-- Arcturus Therapeutics Holdings Inc. (the “Company”, “Arcturus”, Nasdaq: ARCT), a commercial messenger RNA medicines company focused on the development of infectious disease vaccines and opportunities within liver and respiratory rare diseases, today announced its financial results for the fourth quarter ended December 31, 2024 , and provided corporate updates. “We continue to progress our flagship rare disease programs and look forward to sharing meaningful Phase 2 interim data from our cystic fibrosis (CF) and ornithine transcarbamylase (OTC) deficiency programs in Q2 2025,” said Joseph Payne , President & CEO of Arcturus Therapeutics . “Arcturus continues to make excellent progress with our STARR® sa-mRNA vaccines pipeline and platform. We are very pleased to have recently received European Commission approval for KOSTAIVE® and MHLW approval for Meiji Seika Pharma and ARCALIS to add commercial manufacturing sites in Japan . Our team continues to work diligently with CSL Seqirus to prepare KOSTAIVE regulatory filings for the United States and the United Kingdom.” Recent Corporate Highlights Arcturus has advanced the development of ARCT-032, an mRNA therapeutic candidate for cystic fibrosis. In December 2024 , the Company initiated dosing of the first CF participant in an open label Phase 2 multiple ascending dose study. Each adult participant in the Phase 2 CF study (NCT06747858) is expected to receive daily inhaled treatments of ARCT-032 over a period of 28 days. The trial involves a relatively low number of study visits and 12 weeks of follow up. The Company expects to provide interim data from participants who completed dosing in the ARCT-032 Phase 2 study by the end of Q2 2025. Arcturus has advanced the development of ARCT-810, an mRNA therapeutic candidate for ornithine transcarbamylase (OTC) deficiency. In December 2024 , the Company initiated dosing of the first OTC deficient participant who received 0.5 mg/kg in the Phase 2 multiple ascending dose study. Each adult and adolescent participant in the open label Phase 2 OTC deficiency study (NCT06488313) is expected to receive five intravenous infusions of ARCT-810 over a period of two months. The Company previously announced the completion of the dosing phase (N = 8; 0.3 mg/kg) in a placebo-controlled European study enrolling OTC deficient individuals. The Company expects to provide interim data from participants who completed dosing in the ARCT-810 Phase 2 study by the end of Q2 2025. Arcturus received approval from the European Commission (EC) in February for KOSTAIVE, the world’s first approved sa-mRNA COVID-19 vaccine. The centralized marketing authorization of KOSTAIVE provided by the EC is valid in all 27 European Union (EU) member states and 3 additional European Economic Area (EEA) countries. The approval is based on positive clinical data from several studies, including an integrated phase 1/2/3 study demonstrating KOSTAIVE’s efficacy and tolerability against COVID-19, and a Phase 3 COVID-19 booster trial, which achieved higher immunogenicity results compared to a conventional mRNA COVID-19 vaccine comparator. A follow-up analysis evaluating a booster dose of KOSTAIVE also showed that the vaccine elicited superior immunogenicity and antibody persistence for up to 12 months post vaccination against multiple SARS-CoV-2 strains in both younger and older adult age groups versus the mRNA comparator. The approval follows a positive opinion adopted by the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) on December 12, 2024 . In January, Meiji Seika Pharma , along with Arcturus’ manufacturing joint venture ARCALIS , received Ministry of Health, Labour and Welfare (MHLW) approval for adding commercial manufacturing sites in Japan for KOSTAIVE. Domestically produced products with active pharmaceutical ingredients manufactured at ARCALIS’s Minami-soma facilities, and formulated at Meiji Seika Pharmatech, are now able to be shipped for commercial use in Japan . Meiji Seika Pharma announced an investment in ARCALIS, Inc. in November 2024 . The combination of ARCALIS' advanced technology and operations in mRNA pharmaceuticals and vaccines with Meiji Seika Pharma's expertise in manufacturing, post-marketing safety management and stable product supply is expected to significantly improve the supply of mRNA vaccines in Japan . In February, Meiji Seika Pharma submitted a manufacturing and marketing application for Two-Dose Vial of KOSTAIVE, to the Pharmaceuticals and Medical Devices Agency (PMDA) in Japan . The Company initiated the Phase 1 study of ARCT-2304, a self-amplifying mRNA (sa-mRNA) vaccine candidate, also known as LUNAR-H5N1, for active immunization to prevent pandemic influenza disease caused by H5N1 virus. LUNAR-H5N1 is the third STARR® mRNA vaccine candidate to enter the clinic. Arcturus received clearance from the FDA to begin an H5N1 pandemic flu vaccine clinical trial in November 2024 . The clinical study is funded by Biomedical Advanced Research and Development Authority (BARDA) and designed to enroll approximately 200 healthy adults in the United States . First Phase 1 participant was dosed December 2024 , and the Company expects interim Phase 1 data in H2 2025. The primary objective of this initial clinical trial is to evaluate safety and immune responses of three different dose levels and two different vaccination schedules of ARCT-2304 vaccine. Immune responses are measured by hemagglutination inhibition (HAI), virus microneutralization (MN) and neuraminidase enzyme-linked lectin assays (ELLA). In February, the Company announced the appointment of Moncef Slaoui , Ph.D., as Chair Designate. Dr. Slaoui is currently on the Company’s Board of Directors, a position he has held since June 2024 . Each adult participant in the Phase 2 CF study (NCT06747858) is expected to receive daily inhaled treatments of ARCT-032 over a period of 28 days. The trial involves a relatively low number of study visits and 12 weeks of follow up. The Company expects to provide interim data from participants who completed dosing in the ARCT-032 Phase 2 study by the end of Q2 2025. Each adult and adolescent participant in the open label Phase 2 OTC deficiency study (NCT06488313) is expected to receive five intravenous infusions of ARCT-810 over a period of two months. The Company previously announced the completion of the dosing phase (N = 8; 0.3 mg/kg) in a placebo-controlled European study enrolling OTC deficient individuals. The Company expects to provide interim data from participants who completed dosing in the ARCT-810 Phase 2 study by the end of Q2 2025. The centralized marketing authorization of KOSTAIVE provided by the EC is valid in all 27 European Union (EU) member states and 3 additional European Economic Area (EEA) countries. The approval is based on positive clinical data from several studies, including an integrated phase 1/2/3 study demonstrating KOSTAIVE’s efficacy and tolerability against COVID-19, and a Phase 3 COVID-19 booster trial, which achieved higher immunogenicity results compared to a conventional mRNA COVID-19 vaccine comparator. A follow-up analysis evaluating a booster dose of KOSTAIVE also showed that the vaccine elicited superior immunogenicity and antibody persistence for up to 12 months post vaccination against multiple SARS-CoV-2 strains in both younger and older adult age groups versus the mRNA comparator. The approval follows a positive opinion adopted by the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) on December 12, 2024 . Domestically produced products with active pharmaceutical ingredients manufactured at ARCALIS’s Minami-soma facilities, and formulated at Meiji Seika Pharmatech, are now able to be shipped for commercial use in Japan . Meiji Seika Pharma announced an investment in ARCALIS, Inc. in November 2024 . The combination of ARCALIS' advanced technology and operations in mRNA pharmaceuticals and vaccines with Meiji Seika Pharma's expertise in manufacturing, post-marketing safety management and stable product supply is expected to significantly improve the supply of mRNA vaccines in Japan . Arcturus received clearance from the FDA to begin an H5N1 pandemic flu vaccine clinical trial in November 2024 . The clinical study is funded by Biomedical Advanced Research and Development Authority (BARDA) and designed to enroll approximately 200 healthy adults in the United States . First Phase 1 participant was dosed December 2024 , and the Company expects interim Phase 1 data in H2 2025. The primary objective of this initial clinical trial is to evaluate safety and immune responses of three different dose levels and two different vaccination schedules of ARCT-2304 vaccine. Immune responses are measured by hemagglutination inhibition (HAI), virus microneutralization (MN) and neuraminidase enzyme-linked lectin assays (ELLA). Financial Results for the three months ended December 31, 2024 , and the year ended December 31, 2024 Revenues in conjunction with strategic alliances and collaborations: Arcturus’ primary revenue streams include license fees, consulting and related technology transfer fees, reservation fees and collaborative payments received from research and development arrangements with pharmaceutical and biotechnology partners. For the three months ended December 31, 2024 , we reported revenue of $22.8 million , a decrease of $8.1 million from the $30.9 million reported in the same period in 2023. The decline was attributable to lower milestone achievements from the CSL agreement during the fourth quarter of 2024. For the year ended December 31, 2024 , we reported revenue of $152.3 million , a decrease of $14.5 million from the $166.8 million reported for the year ended 2023. The decrease was due to lower milestone achievements from the CSL agreement, offset by increased BARDA revenue due to progress of the pandemic flu program. Operating expenses: Total operating expenses for the three months ended December 31, 2024 , were $56.2 million compared with $49.1 million for the three months ended December 31, 2023 . Total operating expenses for the year ended December 31, 2024 , were $248.0 million compared with $245.0 million for the year ended December 31, 2023 . Research and development expenses: Research and development expenses consist primarily of external manufacturing costs, in vivo research studies and clinical trials performed by contract research organizations, clinical and regulatory consultants, personnel-related expenses, facility-related expenses and laboratory supplies related to conducting research and development activities. Research and development expenses were $43.8 million for the three months ended December 31, 2024 , compared with $36.6 million for the three months ended December 31, 2023 . Additionally, research and development expenses were $195.2 million for the year ended December 31, 2024 , compared with $192.1 million for the year ended December 31, 2023 . The increase in research and development expenses for both the quarter and the full year was primarily driven by higher clinical trial costs associated with our OTC and CF programs, as well as the COVID-19 and LUNAR-FLU programs in collaboration with CSL. However, the increase was partially offset by a reduction in manufacturing expenses related to clinical trials and drug supply agreements as part of the COVID-19 program. General and Administrative Expenses: General and administrative expenses primarily consist of salaries and related benefits for executive, administrative, legal and accounting functions and professional service fees for legal and accounting services as well as other general and administrative expenses. General and administrative expenses were $12.4 million for the three months ended December 31, 2024 , compared with $12.5 million for the three months ended December 31, 2023 . Additionally, General and administrative expenses were $52.8 million for the year ended December 31, 2024 , compared with $52.9 million for the year ended December 31, 2023 . These expenses remained relatively consistent between the two periods. We expect general and administrative expenses to decrease slightly during the next twelve months driven by lower share-based compensation costs and a reduction in general and administrative expenses related to the commercial transition of the COVID program to CSL. Net Loss: For the three months ended December 31, 2024 , Arcturus reported a net loss of approximately $30.0 million , or ( $1.11 ) per diluted share, compared with a net loss of $11.7 million , or ( $0.44 ) per diluted share for the three months ended December 31, 2023 . Additionally, for the year ended December 31, 2024 , Arcturus reported a net loss of approximately $80.9 million , or ( $3.00 ) per diluted share, compared with a net loss of $29.7 million , or ( $1.12 ) per diluted share for the year ended December 31, 2023 . Cash Position and Balance Sheet: Cash, cash equivalents and restricted cash were $293.9 million as of December 31, 2024 , and $348.9 million on December 31, 2023 . Arcturus achieved a total of approximately $473.1 million in upfront payments and milestones from CSL as of December 31, 2024 , and expects to continue to receive future milestone payments from CSL supporting the ongoing development of the COVID program. During the quarter ended December 31, 2024 , CSL reported to Arcturus that Arcturus’ share of gross profit from sales of KOSTAIVE was approximately $28.0 million . This amount will be credited against Arcturus’ share of the COVID-19 program costs paid by CSL. When CSL has recouped Arcturus’ share of such costs, Arcturus will begin to receive shared net profit payments from CSL for sales of KOSTAIVE, consistent with Arcturus’ eligibility to receive a 40% share of net profits from COVID-19 vaccine sales. Based on the current pipeline and programs, the cash runway is expected to extend until the end of Q1 2027. Arcturus Therapeutics Fourth Quarter and Full Year 2024 Earnings Conference Call Thursday, March 6, 2025 @4:30 p.m. ET Domestic: 1-800-267-6316 International: 1-203-518-9783 Conference ID: ARCTURUS Webcast: Link About Arcturus Founded in 2013 and based in San Diego, California , Arcturus Therapeutics Holdings Inc. (Nasdaq: ARCT) is a commercial mRNA medicines and vaccines company with enabling technologies: (i) LUNAR® lipid-mediated delivery, (ii) STARR® mRNA technology (sa-mRNA) and (iii) mRNA drug substance along with drug product manufacturing expertise. Arcturus developed KOSTAIVE®, the first self-amplifying messenger RNA (sa-mRNA) COVID vaccine in the world to be approved. Arcturus has an ongoing global collaboration for innovative mRNA vaccines with CSL Seqirus, and a joint venture in Japan , ARCALIS , focused on the manufacture of mRNA vaccines and therapeutics. Arcturus’ pipeline includes RNA therapeutic candidates to potentially treat ornithine transcarbamylase (OTC) deficiency and cystic fibrosis (CF), along with its partnered mRNA vaccine programs for SARS-CoV-2 (COVID-19) and influenza. Arcturus’ versatile RNA therapeutics platforms can be applied toward multiple types of nucleic acid medicines including messenger RNA, small interfering RNA, circular RNA, antisense RNA, self-amplifying RNA, DNA, and gene editing therapeutics. Arcturus' technologies are covered by its extensive patent portfolio (over 500 patents and patent applications in the U.S. , Europe , Japan , China , and other countries). For more information, visit www.ArcturusRx.com. In addition, please connect with us on Twitter and LinkedIn. Forward Looking Statements This press release contains forward-looking statements that involve substantial risks and uncertainties for purposes of the safe harbor provided by the Private Securities Litigation Reform Act of 1995. Any statements, other than statements of historical fact included in this press release, are forward-looking statements, including those regarding strategy, future operations, the likelihood of success of the Company’s pipeline (including ARCT-032 and ARCT-810) and partnered programs (including the COVID-19 and flu programs partnered with CSL Seqirus), the anticipated timing for providing interim data from the ARCT-032 Phase 2 CF study and the ARCT-810 Phase 2 OTC deficiency study, the completion of and timing for KOSTAIVE regulatory filings for the United States and United Kingdom , the expected treatment protocol for the ARCT-032 Phase 2 CF study, the expected infusions and timing therefor for the ARCT-810 Phase 2 OTC deficiency study, the potential supply of mRNA vaccines by Meiji Seika Pharma and ARCALIS , the likelihood that CSL Seqirus will recoup the development costs of the COVID-19 program and that Arcturus will receive net profit payments from CSL Seqirus for sales of KOSTAIVE, the likelihood that preclinical or clinical data will be predictive of future clinical results, the likelihood or timing of collection of accounts receivables including expected payments from CSL Seqirus, its current cash position and expected cash burn and runway, and the impact of general business and economic conditions. Arcturus may not actually achieve the plans, carry out the intentions or meet the expectations or projections disclosed in any forward-looking statements such as the foregoing and you should not place undue reliance on such forward-looking statements. These statements are only current predictions or expectations, and are subject to known and unknown risks, uncertainties, and other factors that may cause our or our industry’s actual results, levels of activity, performance or achievements to be materially different from those anticipated by the forward-looking statements, including those discussed under the heading "Risk Factors" in Arcturus’ most recent Annual Report on Form 10-K, and in subsequent filings with, or submissions to, the SEC , which are available on the SEC’s website at www.sec.gov. Except as otherwise required by law, Arcturus disclaims any intention or obligation to update or revise any forward-looking statements, which speak only as of the date they were made, whether as a result of new information, future events or circumstances or otherwise. ARCTURUS THERAPEUTICS HOLDINGS INC. AND ITS SUBSIDIARIES CONSOLIDATED BALANCE SHEETS As of December 31 , (in thousands, except per share data) 2024 2023 Assets Current assets: Cash and cash equivalents $ 237,028 $ 292,005 Restricted cash 55,000 55,000 Accounts receivable 3,974 32,064 Prepaid expenses and other current assets 9,977 7,521 Total current assets 305,979 386,590 Property and equipment, net 9,531 12,427 Operating lease right-of-use asset 26,674 28,500 Non-current restricted cash 1,885 1,885 Total assets $ 344,069 $ 429,402 Liabilities and Stockholders’ Equity Current liabilities: Accounts payable $ 7,194 $ 5,279 Accrued liabilities 38,781 31,881 Deferred revenue 19,514 44,829 Total current liabilities 65,489 81,989 Deferred revenue, net of current portion 12,604 42,496 Operating lease liability, net of current portion 24,998 25,907 Other non-current liabilities — 497 Total liabilities 103,091 150,889 Stockholders’ equity: Common stock: $0.001 par value; 60,000 shares authorized; issued and outstanding shares were 27,000 at December 31, 2024 and 26,828 at December 31, 2023 27 27 Additional paid-in capital 689,758 646,352 Accumulated deficit (448,807 ) (367,866 ) Total stockholders’ equity 240,978 278,513 Total liabilities and stockholders’ equity $ 344,069 $ 429,402 ARCTURUS THERAPEUTICS HOLDINGS INC. AND ITS SUBSIDIARIES CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE (LOSS) INCOME Year Ended December 31 , (in thousands, except per share data) 2024 2023 2022 Revenue: Collaboration revenue $ 138,389 $ 157,748 $ 205,755 Grant revenue 13,921 9,051 244 Total revenue 152,310 166,799 205,999 Operating expenses: Research and development, net 195,156 192,133 147,751 General and administrative 52,823 52,871 46,071 Total operating expenses 247,979 245,004 193,822 (Loss) income from operations (95,669 ) (78,205 ) 12,177 Loss from equity-method investment — — (515 ) Loss from foreign currency (471 ) (229 ) (598 ) Finance income (expense), net 15,195 16,591 (420 ) Gain on debt extinguishment — 33,953 — Net (loss) income before income taxes (80,945 ) (27,890 ) 10,644 (Benefit) provision for income taxes (4 ) 1,835 1,295 Net (loss) income (80,941 ) (29,725 ) 9,349 Comprehensive (loss) income $ (80,941 ) $ (29,725 ) $ 9,349 (Loss) earnings per share: Basic $ (3.00 ) $ (1.12 ) $ 0.35 Diluted $ (3.00 ) $ (1.12 ) $ 0.35 Weighted-average shares used in calculation of (loss) earnings per share: Basic 27,000 26,628 26,445 Diluted 27,000 26,628 27,093 ARCTURUS THERAPEUTICS HOLDINGS INC. AND ITS SUBSIDIARIES CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (UNAUDITED) Three Months Ended December 31 , (in thousands, except per share data) 2024 2023 Revenue: Collaboration revenue $ 21,000 $ 25,078 Grant revenue 1,766 5,777 Total revenue 22,766 30,855 Operating expenses: Research and development, net 43,780 36,620 General and administrative 12,380 12,507 Total operating expenses 56,160 49,127 Loss from operations (33,394 ) (18,272 ) Gain (loss) gain from foreign currency 171 (54 ) Finance expense, net 3,214 6,881 Net loss income before income taxes (30,009 ) (11,445 ) Provision for income taxes (4 ) 262 Net loss (30,005 ) (11,707 ) Comprehensive loss $ (30,005 ) $ (11,707 ) Loss per share: Basic and diluted $ (1.11 ) $ (0.44 ) Weighted-average shares used in calculation of loss per share: Basic and diluted 27,000 26,628 View source version on businesswire.com: https://www.businesswire.com/news/home/20250306214195/en/ Arcturus Therapeutics Public Relations & Investor Relations Neda Safarzadeh VP, Head of IR/PR/Marketing (858) 900-2682 IR@ArcturusRx.com Source: Arcturus Therapeutics Holdings 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: TRAWS data on file 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 SOURCE Traws Pharma, Inc. WANT YOUR COMPANY'S NEWS FEATURED ON PRNEWSWIRE.COM? 440k+ Newsrooms & Influencers 9k+ Digital Media Outlets 270k+ Journalists Opted In GET STARTED

Investigational agent in development for treatment or prevention of H5N1 Bird Flu Phase 1 dosing completed in healthy volunteers Potent inhibition of drug-resistant and bird flu viruses in vitro In vivo study in mice, with H5N1 isolated from an infected dairy worker, showed potent protection and suppression of virus replication in lungs Phase 2 study expected to begin in H1 2025 Traws Pharma is expanding its influenza program to address the potential threat of bird flu NEWTOWN, Pa., Dec. 23, 2024 /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 progress in the development of its investigational one-dose influenza (flu) investigational therapy, tivoxavir marboxil for treatment of H5N1 bird flu. "The spread of avian influenza in wild and domestic animal populations including mammals, brings increasing risk for adaptation to humans and subsequent spread in the population" 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). "Bird flu is an occupational hazard for poultry and dairy workers. With increasing numbers of human infections and recent reports of severe cases, we should be alert to the rising potential for epidemic or pandemic spread of bird flu." "In laboratory testing, tivoxavir marboxil inhibited multiple isolates of highly pathogenic avian influenza H5N1. We evaluated the effects of drug treatment in mice exposed to human H5N1, where the virus was isolated from a dairy worker exposed to infected cattle," said C. David Pauza, PhD, Chief Science Officer for Traws Pharma. "Oral treatment with tivoxavir marboxil after the virus infection resulted in complete survival and lung virus levels below the limit of quantitation1. This result is highly encouraging for future clinical development of tivoxavir marboxil for treating human H5N1 influenza." "Current topline data from our Phase I clinical trial demonstrated safety and tolerability of tivoxavir marboxil, and maintenance of drug levels in blood above the EC90 for longer than 23 days1, with topline data for a higher dose still to come," said Werner Cautreels, PhD, Chief Executive Officer of Traws Pharma. "In addition, the potential for tivoxavir marboxil as a treatment for H5N1 bird flu was demonstrated in an animal model." Topline Phase 1 Results with Tivoxavir Marboxil The Phase 1 trial was a randomized, double-blind, placebo-controlled study to assess the safety, tolerability, and pharmacokinetics (PK) of ascending doses for one-time tivoxavir marboxil treatment in healthy, influenza-negative, adult volunteers. No treatment-related adverse events were reported during the Phase 1 study. Current topline data from this study showed that a single dose of tivoxavir marboxil maintained plasma drug levels consistently above the EC90 for more than twenty-three days, with topline data for a higher dose still to come. 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 H5N1 Bird Flu The virus, also known as Type A H5N1 was detected for the first time in U.S. dairy cattle in March 2024. Since then, bird flu has been confirmed in at least 866 herds in 16 states. More than 60 people in eight states have been infected according to the U.S. Centers for Disease Control and Prevention. Health officials confirmed in December 2024 the first known severe illness in the U.S. caused by bird flu7. The California governor declared a state of emergency as the virus rampages through dairy cattle in that state8. About Tivoxavir Marboxil Seasonal influenza is estimated to represent a 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 (also known as AV5124 or TRX-100) 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, including the highly pathogenic avian flu, in preclinical studies. The drug candidate's Phase 1 pharmacokinetic (PK) profile in healthy subjects, including the ability to achieve plasma levels that are consistently above the EC90 (as determined in laboratory studies), for more than twenty-three days with higher dose data to come, may enable a single dose prophylaxis regimen. These data, combined with good overall tolerability results in healthy subjects and prevention of lethal influenza in an animal model, support further development of tivoxavir marboxil as a one-time treatment for influenza. Source information: TRAW data on file Flu is burdensome Flu hospitalizations Flu mortality Flu in older adults Avian flu Bird flu CDC California About Traws Pharma, Inc. Antiviral Program 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 1, 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 Pharma is committed to delivering novel compounds for unmet medical needs using state-of-the-art drug development technology. With a focus on product safety and a commitment to patients in need that are specifically vulnerable, we aim to build solutions for important medical challenges and alleviate the burden of viral infections 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 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. Traws Pharma Contacts: Mark Guerin Traws Pharma, Inc. 267-759-3680 SOURCE Traws Pharma, Inc. WANT YOUR COMPANY'S NEWS FEATURED ON PRNEWSWIRE.COM? 440k+ Newsrooms & Influencers 9k+ Digital Media Outlets 270k+ Journalists Opted In GET STARTED