OS Therapies (OSTX) Registration Filing summary

Company overview and business model

• Clinical-stage biopharmaceutical company focused on developing treatments for Osteosarcoma and other solid tumors, primarily affecting children and young adults.

• Lead product candidate is OST-HER2, an off-the-shelf immunotherapy using a genetically modified Listeria monocytogenes expressing HER2 peptides.

• Pipeline includes OST-tADC, a tunable antibody-drug conjugate platform targeting ovarian, lung, pancreatic, and other cancers; currently in preclinical development.

• OST-HER2 has orphan drug, rare pediatric disease, and fast track designations; breakthrough therapy designation requested in May 2024.

• Holds a conditional USDA license for OST-HER2 in canine Osteosarcoma, with potential out-licensing for veterinary use.

Financial performance and metrics

• No revenue generated to date; company has incurred significant operating losses and anticipates continued losses for the foreseeable future.

• Net loss for the year ended December 31, 2023 was $7.9 million; for the three months ended March 31, 2024, net loss was $1.5 million.

• As of March 31, 2024, cash balance was $0.1 million, with an accumulated deficit of $31.0 million.

• Operating expenses for 2023 were $4.3 million, primarily for R&D and G&A.

• Substantial doubt exists about the company's ability to continue as a going concern without additional capital.

Use of proceeds and capital allocation

• Net proceeds of approximately $6.7 million expected from the IPO (or $7.8 million if underwriters' option is exercised).

• $4.2 million allocated to advance OST-HER2 clinical development for Osteosarcoma.

• $1.2 million allocated to OST-tADC preclinical and IND-enabling studies for ovarian cancer.

• Remaining $1.3 million for discovery, new product development, working capital, and general corporate purposes.

• Funds expected to support operations for 12–18 months; additional capital will be required thereafter.