OS Therapies

• OS Therapies' investigational immunotherapy OST-HER2 demonstrates statistically significant benefit in Phase 2b clinical trials for recurrent osteosarcoma, with FDA submission planned for 2025. • The treatment leverages Listeria bacteria to target HER2-expressing cancer cells and has received multiple regulatory designations including Rare Pediatric Disease Designation and Fast-Track status. • The innovative therapy will be featured in PBS documentary "Shelter Me: The Cancer Pioneers," highlighting the importance of comparative oncology between human and canine osteosarcoma, which share 96% genetic homology.

OST-HER2 demonstrated a statistically significant 12-month event-free survival (EFS) rate of 33.3% compared to 20% in historical controls for recurrent, fully resected osteosarcoma with lung metastases.

OS Therapies has initiated commercial manufacturing for OST-HER2, an immunotherapy targeting HER2, in preparation for a BLA submission to the FDA.

OS Therapies has announced a $6 million private placement to fund the clinical and regulatory milestones for OST-HER2, its lead therapeutic candidate.

• OS Therapies expects to release topline data from its Phase 2b clinical trial of OST-HER2 in resected, recurrent osteosarcoma in December 2024. • The company completed the treatment phase of the Phase 2b trial, dosing 41 patients across 21 clinical trial sites in the United States. • OST-HER2 has received Rare Pediatric Disease, Fast Track, and Orphan Drug Designations from regulatory agencies, potentially granting a Priority Review Voucher upon BLA approval. • OS Therapies is in active discussions with the FDA regarding Breakthrough Therapy Designation for OST-HER2, aiming to expedite the availability of this immunotherapy.

OS Therapies' Phase 2b trial of OST-HER2 met its primary endpoint, demonstrating a statistically significant improvement in 12-month Event Free Survival in recurrent osteosarcoma patients.

• OS Therapies has completed dosing in its Phase 2b clinical trial of OST-HER2 for recurrent osteosarcoma, with topline data anticipated in December 2024. • The trial enrolled 41 patients across 21 U.S. sites, evaluating OST-HER2, a novel cancer immunotherapy targeting HER2-expressing cancer cells. • OS Therapies reported a net operating loss of $2.875 million in Q3 2024, impacted by IPO expenses, but anticipates revenue generation upon potential FDA approval. • OST-HER2 has received Rare Pediatric Disease, Fast Track, and Orphan Drug Designations from the FDA and EMA, potentially accelerating its path to market.