OS Therapies Inc. Reports Landmark 2‑Year Overall Survival Results and Advances in Regulatory Strategy
OS Therapies Inc. (NYSE American: OSTX), a clinical‑stage biopharmaceutical company focused on osteosarcoma and other solid tumors, announced a series of developments that could accelerate the pathway to market for its lead candidate, OST‑HER2. The company’s most recent data, presented on October 10, 2025, show a statistically significant improvement in two‑year overall survival (OS) among patients treated with OST‑HER2 compared with historical controls. Concurrently, OS Therapies secured positive regulatory feedback from the European Medicines Agency (EMA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA), positioning the company for a conditional marketing authorization (CMA).
2‑Year Overall Survival Data from the Phase 2b Fully‑Resected Metastatic Osteosarcoma Trial
| Metric | OST‑HER2 (n = 36 evaluable) | Historical Control | Statistical Significance |
|---|---|---|---|
| Two‑year overall survival | 75 % (27/36) | 40 % | p < 0.0001 |
| 12‑month event‑free survival → 2‑year OS | 100 % | – | – |
| 12‑month event‑free survival → 2‑year OS (non‑EFS group) | 59 % | – | – |
Key points from the announcement:
- Robust Survival Benefit: The 75 % two‑year OS rate represents a dramatic improvement over the 40 % rate seen in historical cohorts, underscoring the therapeutic potential of the off‑the‑shelf immunotherapy candidate.
- Consistency Across Subgroups: Patients who achieved 12‑month event‑free survival (EFS) all survived at two years, while 59 % of patients who did not reach EFS still achieved two‑year OS, suggesting a durable benefit even in less favorable sub‑populations.
- Statistical Confidence: The highly significant p‑value (p < 0.0001) indicates that the observed difference is unlikely to be due to chance.
These results, the first final overall survival data from a Phase 2b study of OST‑HER2, provide a compelling foundation for pursuing regulatory approval and expanding clinical development.
Positive Regulatory Interaction with the EMA and MHRA
On October 6, 2025, OS Therapies met with the EMA rapporteur, MEB, to discuss the clinical data generated to date. The rapporteur expressed confidence that the two‑year OS endpoint, with its statistically significant final results, could be accepted as a primary endpoint for a conditional marketing authorization. The meeting clarified that:
- Safety, Non‑Clinical, and CMC Data are Sufficient: The rapporteur viewed the combined data set as adequate to support a CMA submission, streamlining the pathway to a marketing application.
- Pathway to Confirmatory Randomized Program: The discussion laid out a plan for a confirmatory randomized trial that would further validate OST‑HER2’s efficacy and support potential label expansion.
- Alignment with MHRA Scientific Advice: In parallel, the MHRA granted an expedited Market Access Scientific Advice meeting, reinforcing the UK’s support for the CMA process.
Formal EMA Scientific Advice is expected in December 2025, and the company will use these insights to refine its regulatory strategy.
Engagement with the Scientific and Investor Community
OS Therapies is actively sharing its progress through a series of high‑profile conferences and media appearances scheduled for October and November 2025:
| Event | Date | Focus |
|---|---|---|
| Cell and Gene Meeting (Mesa, Phoenix) | Oct 6‑8 | CEO presentation, partnership outreach |
| Roth Healthcare (New York) | Oct 9 | Corporate update, CBO discussion |
| FDA/OSI Osteosarcoma Workshop (Washington, DC) | Oct 10 | Regulatory dialogue |
| BIOFuture Spotlight (New York) | Oct 13‑15 | Scientific findings |
| Daytime Emmy Awards (Pasadena) | Oct 17 | Documentary “Shelter Me: Cancer Pioneers” featuring trial participants |
| Maxim Growth Summit (New York) | Oct 22 | Investor engagement |
| BIO‑Europe (Vienna) | Nov 3‑5 | Partnering and partnership discussions |
These appearances not only raise the company’s visibility among clinicians, investors, and regulators but also foster collaborations that could accelerate the commercialization of OST‑HER2.
Market Context
- Current Share Price (Oct 8, 2025): $2.04
- 52‑Week High/Low: $7.00 / $1.12
- Market Capitalization: Approximately $64 million USD
Despite the modest valuation, the recent clinical and regulatory milestones are likely to influence investor perception positively. The company’s ability to demonstrate a clinically meaningful survival benefit in a rare and challenging disease population positions it as a noteworthy player within the oncology therapeutics landscape.
Outlook
OS Therapies’ Phase 2b data, coupled with encouraging regulatory feedback, suggest a clear path toward a conditional marketing authorization in Europe. Successful navigation of the EMA and MHRA pathways, alongside continued engagement with the scientific community, will be crucial for translating these results into a tangible treatment option for patients with metastatic osteosarcoma. The company’s forthcoming conference presentations and potential partnership opportunities will further clarify its strategic trajectory in the coming months.
