New York, New York — January 5, 2026 — Leads & Copy —
OS Therapies Inc. (NYSE American: OSTX) provided a corporate outlook for the first half of 2026, highlighting planned regulatory submissions for its lead candidate OST-HER2 in the U.S., U.K., and Europe. The company anticipates releasing Phase 2b biomarker data from its Metastatic Osteosarcoma Program in early January 2026 and expects to participate in meetings with regulatory agencies.
According to Chairman & CEO Paul Romness, OS Therapies aims to improve the standard of care for patients with metastatic osteosarcoma. Romness noted that 2025 was a transformative year, marked by promising clinical trial results for OST-HER2 and significant interactions with regulatory agencies regarding conditional marketing authorizations in 2026. The company has aligned its strategy with the specific feedback received from these agencies.
With OST-HER2 regulatory submissions winding down in the second half of Q1 2026, OS Therapies anticipates making regulatory progress in its human OST-503 and OST-504 programs. The company also plans to complete a go-public transaction for its OS Animal Health subsidiary in the first half of 2026, with a confidential filing with the SEC expected soon.
The company expects to release biomarker data from its Phase 2b human clinical trial of OST-HER2, which focuses on preventing or delaying recurrent, fully resected, pulmonary metastatic osteosarcoma, during the week of the J.P. Morgan Healthcare Conference 2026.
OS Therapies intends to file a Biologics License Application (BLA) with the U.S. FDA under the Accelerated Approval Program by the end of January 2026. It plans to complete Marketing Authorisation Application (MAA) submissions seeking conditional marketing authorization with the U.K. MHRA and Europe’s EMA by the end of February 2026 and March 2026, respectively.
Following these submissions, the company anticipates multiple meetings with regulatory authorities in the U.S., U.K., and Europe during the first half of 2026 to discuss proposed surrogate clinical efficacy endpoints, confirmatory trial design, and post-market authorization monitoring plans. Subject to these additional meetings requested by the FDA, MHRA and EMA, OS Therapies anticipates potential regulatory approval for OST-HER2 in the U.K. in Q2 2026, in the United States in Q3 2026 and in Europe by the end of Q4 2026.
OST-HER2 has received Orphan Drug Designation (ODD) and Fast Track Designation from the FDA and EMA, and Rare Pediatric Disease Designation (RPDD) from the FDA. Under the RPDD program, if the company receives Accelerated Approval prior to September 30, 2026, it will become eligible to receive a Priority Review Voucher (PRV) that it intends to sell. The most recent PRV sale valued at $160 million occurred in June 2025.
OS Animal Health is seeking regulatory approval for OST-HER2 from the United States Department of Agriculture (USDA) for treating pulmonary metastatic osteosarcoma and frontline osteosarcoma. OST-HER2 was featured in the Emmy-nominated documentary ‘Shelter Me: Cancer Pioneers’ streaming on PBS.
The company expects delayed data from its OST-504 Phase 1 trial in castration resistant prostate cancer in Q1 2026, with an End of Phase 1 meeting with the FDA expected in Q2 2026. Additionally, an End of Phase 2 meeting with the FDA is expected in Q2 2026 to review OST-503 non-small cell lung cancer frontline trial results in combination with Keytruda®.
OS Therapies is focused on developing treatments for osteosarcoma and other solid tumors, and is the world leader in listeria-based cancer immunotherapies. OST-HER2 leverages the immune-stimulatory effects of Listeria bacteria to generate a strong immune response targeting the HER2 protein. In veterinary oncology, OST-HER2 has been conditionally approved by the USDA for treating canines with osteosarcoma.
The company is also advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC) platform, known as its tunable ADC (tADC) platform.
OS Therapies Contact Information:
Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com
Public Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.com
Source: OS Therapies Inc.
