OS Therapies Announces Statistically Significant Positive Interim 2-Year Overall Survival Data from Phase 2b Clinical Trial of OST-HER2 in the Prevention or Delay of Recurrent, Fully Resected, Pulmonary Metastatic Osteosarcoma
OS Therapies (NYSE American: OSTX) reported significant positive interim results from its Phase 2b trial of OST-HER2 for osteosarcoma treatment. The study showed 66.6% (18 out of 27) of OST-HER2 treated patients achieved 2-year overall survival compared to 40% in the historical control group, with statistical significance (p = 0.0046).
The FDA has issued a Biologics Licensing Application (BLA) number for OST-HER2 ahead of the anticipated BLA filing following the August 27, 2025 End of Phase 2 Meeting. The company is working to align approval metrics for RMAT designation, Breakthrough Therapy designation, and BLA via the Accelerated Approval Program.
Additionally, OS Therapies has been included in the Russell Microcap, Russell Microcap Value, and Russell Microcap Growth indexes.
OS Therapies (NYSE American: OSTX) ha riportato risultati positivi significativi e preliminari dal suo studio di Fase 2b su OST-HER2 per il trattamento dell'osteosarcoma. Lo studio ha mostrato che il 66,6% (18 su 27) dei pazienti trattati con OST-HER2 ha raggiunto una sopravvivenza globale a 2 anni, rispetto al 40% del gruppo di controllo storico, con significativit脿 statistica (p = 0,0046).
La FDA ha assegnato un numero di Biologics Licensing Application (BLA) per OST-HER2 in vista della prevista presentazione della BLA dopo la riunione di fine Fase 2 del 27 agosto 2025. L鈥檃zienda sta lavorando per allineare i parametri di approvazione per la designazione RMAT, la designazione Breakthrough Therapy e la BLA tramite il Programma di Approvazione Accelerata.
Inoltre, OS Therapies 猫 stata inclusa negli indici Russell Microcap, Russell Microcap Value e Russell Microcap Growth.
OS Therapies (NYSE American: OSTX) inform贸 resultados interinos positivos significativos de su ensayo de Fase 2b con OST-HER2 para el tratamiento del osteosarcoma. El estudio mostr贸 que el 66.6% (18 de 27) de los pacientes tratados con OST-HER2 lograron una supervivencia global a 2 a帽os en comparaci贸n con el 40% del grupo de control hist贸rico, con significancia estad铆stica (p = 0.0046).
La FDA ha emitido un n煤mero de Solicitud de Licencia de Biol贸gicos (BLA) para OST-HER2 antes de la presentaci贸n anticipada de la BLA tras la Reuni贸n de Fin de Fase 2 del 27 de agosto de 2025. La compa帽铆a est谩 trabajando para alinear los criterios de aprobaci贸n para la designaci贸n RMAT, la designaci贸n de Terapia Innovadora y la BLA a trav茅s del Programa de Aprobaci贸n Acelerada.
Adem谩s, OS Therapies ha sido incluida en los 铆ndices Russell Microcap, Russell Microcap Value y Russell Microcap Growth.
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霕愴暅 OS Therapies電� Russell Microcap, Russell Microcap Value, Russell Microcap Growth 歆�靾�鞐� 韽暔霅橃棃鞀惦媹雼�.
OS Therapies (NYSE American : OSTX) a annonc茅 des r茅sultats interm茅diaires positifs significatifs de son essai de phase 2b sur OST-HER2 pour le traitement de l鈥檕st茅osarcome. L鈥櫭﹖ude a montr茅 que 66,6 % (18 sur 27) des patients trait茅s avec OST-HER2 ont atteint une survie globale 脿 2 ans, contre 40 % dans le groupe t茅moin historique, avec une signification statistique (p = 0,0046).
La FDA a attribu茅 un num茅ro de Biologics Licensing Application (BLA) pour OST-HER2 avant le d茅p么t anticip茅 de la BLA suite 脿 la r茅union de fin de phase 2 pr茅vue le 27 ao没t 2025. La soci茅t茅 travaille 脿 aligner les crit猫res d鈥檃pprobation pour la d茅signation RMAT, la d茅signation de th茅rapie r茅volutionnaire et la BLA via le programme d鈥檃pprobation acc茅l茅r茅e.
De plus, OS Therapies a 茅t茅 incluse dans les indices Russell Microcap, Russell Microcap Value et Russell Microcap Growth.
OS Therapies (NYSE American: OSTX) berichtete 眉ber signifikant positive Zwischenergebnisse aus der Phase-2b-Studie von OST-HER2 zur Behandlung von Osteosarkomen. Die Studie zeigte, dass 66,6 % (18 von 27) der mit OST-HER2 behandelten Patienten eine 2-Jahres-Gesamt眉berlebensrate erreichten, verglichen mit 40 % in der historischen Kontrollgruppe, mit statistischer Signifikanz (p = 0,0046).
Die FDA hat eine Biologics Licensing Application (BLA)-Nummer f眉r OST-HER2 vergeben, noch vor der erwarteten BLA-Einreichung nach dem End-of-Phase-2-Meeting am 27. August 2025. Das Unternehmen arbeitet daran, die Zulassungsparameter f眉r die RMAT-Bezeichnung, die Breakthrough Therapy-Bezeichnung und die BLA 眉ber das Accelerated Approval Program abzustimmen.
Dar眉ber hinaus wurde OS Therapies in die Russell Microcap, Russell Microcap Value und Russell Microcap Growth Indizes aufgenommen.
- Significant survival improvement: 66.6% 2-year overall survival rate vs 40% in control group (p = 0.0046)
- FDA issued BLA number, indicating progress toward potential drug approval
- Inclusion in Russell Microcap indexes, increasing visibility to institutional investors
- Multiple regulatory pathways being pursued (RMAT, BTD, Accelerated Approval)
- Still in Phase 2b trials, requiring further clinical validation
- Relatively small patient sample size (27 patients in treatment group)
Insights
OS Therapies reports statistically significant survival improvement for OST-HER2 in osteosarcoma with 66.6% vs 40% survival rates, advancing toward FDA approval.
The interim data from OS Therapies' Phase 2b trial represents a significant therapeutic breakthrough in metastatic osteosarcoma treatment. The reported 66.6% two-year survival rate compared to 40% in historical controls (p=0.0046) demonstrates both statistical significance and clinical meaningfulness in a disease with historically poor outcomes.
This 26.6 percentage point improvement in survival is particularly remarkable for pulmonary metastatic osteosarcoma, a notoriously treatment-resistant form of bone cancer. The strong p-value of 0.0046 indicates the results are highly unlikely to be due to chance, providing robust evidence of efficacy.
The company's strategic regulatory approach is notable - they've secured a BLA number ahead of their End of Phase 2 Meeting and are actively aligning approval metrics across multiple accelerated pathways (RMAT designation, Breakthrough Therapy designation, and Accelerated Approval). This multi-pronged approach suggests confidence in their data package and maximizes chances for expedited review.
The immunotherapy mechanism of OST-HER2 targets HER2 expression in osteosarcoma, which differs from traditional chemotherapy approaches. This represents a paradigm shift in treatment modality for this disease, potentially offering better tolerability alongside improved efficacy.
The off-the-shelf nature of this immunotherapy is also significant, as it eliminates the manufacturing complexities and delays associated with personalized immunotherapies, potentially allowing for faster clinical implementation if approved.
66.6% of OST-HER2 treated patients achieved 2-year overall survival compared with40% in the historical control group (p = 0.0046)- FDA issues Biologics Licensing Application (BLA) number for OST-HER2 in preparation for anticipated BLA filing for the prevention or delay of recurrent, fully resected, pulmonary metastatic osteosarcoma following August 27, 2025 End of Phase 2 Meeting
- Company responds to FDA correspondences seeking to align approval metrics for Regenerative Medicine Advanced Therapy (RMAT) designation, Breakthrough Therapy designation (BTD) and Biologics Licensing Application via Accelerated Approval Program
- Company's NYSE American listing included in the Russell Microcap, Russell Microcap Value and Russell Microcap Growth indexes
New York, New York--(Newsfile Corp. - August 7, 2025) - OS Therapies (NYSE American: OSTX) ("OS Therapies" or "the Company"), a clinical-stage immunotherapy and Antibody Drug Conjugate (ADC) biopharmaceutical company, today announced statistically significant positive updated interim 2-year overall survival data from the Company's Phase 2b trial of off-the-shelf immunotherapy candidate OST-HER2 in the prevention of delay of recurrent, fully resected, pulmonary metastatic osteosarcoma.
Additionally, the US Food & Drug Administration ("FDA") issued a Biologics Licensing Application ("BLA") number for OST-HER2 to receive a BLA submission following the Company's pending August 27, 2025 End of Phase 2 Meeting. The Company has responded to FDA correspondences seeking to align approval metrics for Regenerative Medicine Advanced Therapy (RMAT) designation, Breakthrough Therapy designation (BTD) and BLA via the Accelerated Approval Program.
"We are seeking to bring this novel immunotherapy to market to improve the survival rates in pulmonary metastatic osteosarcoma, and today's updated interim overall survival data continues to show a statistically significant benefit for OST-HER2 treated patients compared with control," said Paul Romness, MPH, Chairman & CEO of OS Therapies. "We believe that continued statistically significant outperformance in overall survival of OST-HER2 treated patients compared with historical control, together with the statistically significant positive 12-month Event Free Survival data presented at MIB Factor in June 2025, will provide the necessary scientific and medical basis to support a BLA under the FDA's Accelerated Approval Program."
Concurrent with this announcement, the Company today announced that its NYSE American listing is included in the Russell Microcap, Russell Microcap Value and Russell Microcap Growth indexes. FTSE Russell determines membership for its Russell indexes primarily by objective, market-capitalization rankings and style attributes. Russell indexes are widely used by investment managers and institutional investors for index funds and as benchmarks for active investment strategies. Approximately
About OS Therapies
OS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 has received Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and Fast-Track and Orphan Drug designations from the U.S. FDA and European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating statistically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study. The Company anticipates submitting a Biologics Licensing Application (BLA) to the U.S. FDA for OST-HER2 in osteosarcoma in 2025 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma.
In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit .
Forward-Looking Statements
Statements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. This information concerns product candidates that are under clinical investigation and which have not yet been approved for marketing by the U.S. Food and Drug Administration (FDA). These product candidates are currently limited by Federal law to investigational use, and no representation is made as to their safety or effectiveness for the purposes for which they are being investigated. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this news release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to the approval of OST-HER2 by the FDA and other risks and uncertainties described under the heading "Risk Factors" in the Company's most recent Annual Report on Form 10-K and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.
OS Therapies Contact Information:
Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
[email protected]
Public Relations
Stephanie Chen
Elev8 New Media
[email protected]
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FAQ
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