OS Therapies to Attend Upcoming Medical, Financial and Industry Conferences

New York, New York and Rockville, Maryland--(Newsfile Corp. - May 26, 2026) -

OS Therapies, Inc.

(NYSE American: OSTX) ("OS Therapies" or "the Company")

, the world leader in gene-edited, listeria-based cancer immunotherapies, announced that it will attend upcoming medical, financial and scientific conferences:

• American Society of Clinical Oncologists 2026Where: Chicago, IL When: May 29, 2026 to June 2, 2026 What: 2.5-year overall survival data announcement
• Jefferies Global Healthcare Conference 2026Where: New York, NY When: June 2, 2026 to June 4, 2026 What: Partnering meetings and select investor meetings
• BIO International Convention 2026Where: San Diego, CA When: June 22, 2026 to June 25, 2026 What: Partnering meetings and panel participation - "ADCs: How can we make bringing ADCs to market a faster, simpler, and more collaborative process?"
• MIB Agents: Factor Osteosarcoma Conference 2026Where: Columbus, OH When: June 25, 2026 to June 27, 2026 What: Data Presentation

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. The Company is the world leader in listeria-based cancer immunotherapies. 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 is designed to target two mutated extracellular epitopes and one mutated intracellular epitope of the HER2 oncogene, requiring only one of these three epitopes to be present in a tumor (or micro-metastasis) to trigger the desired immune response. OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and has received ODD, FTD and ATMP from the 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 clinically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study and the overall survival (OS) secondary endpoint. The Company anticipates receiving a Biologics License Application (BLA) from the U.S. FDA for OST-HER2 in osteosarcoma in 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. The Company also anticipates receiving Conditional Marketing Authorisations from the U.K.'s Medicines and Healthcare products Regulatory Agency and the EMA for OST-HER2 in 2026. 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. The Company also anticipates reading out data from a Phase 1b study of OST-504 in castration resistant prostate cancer in the first half of 2026.

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

www.ostherapies.com

.