OS Therapies Incorporated reported a Q1 2026 net loss of $10.4 million, significantly higher than the $3.9 million loss a year earlier, driven mainly by a sharp increase in research and development spending to $7.4 million.
Cash was $0.9 million at March 31, 2026, against current liabilities of $17.0 million and total stockholders’ deficit of $10.8 million. Management concluded these conditions raise substantial doubt about the company’s ability to continue as a going concern, despite raising new capital through warrant exercises, convertible notes and an April 2026 registered direct offering.
OS Therapies Incorporated notified the SEC that it cannot file its Quarterly Report on Form 10-Q for the period ended March 31, 2026 by the original due date of May 15, 2026 due to additional time needed to complete the financial statement close process. The company states it expects to file the Form 10-Q within the five-calendar-day extension provided by Rule 12b-25.
OS Therapies filed an 8-K describing major regulatory progress for its lead immunotherapy OST-HER2 in recurrent, fully resected pulmonary metastatic osteosarcoma. The European Medicines Agency has begun a rolling review of a Conditional Marketing Authorisation application, using 3-year overall survival as the key endpoint.
The company expects updated 2.5-year overall survival data by mid–second quarter 2026 and 3-year data early in the fourth quarter of 2026, with a potential EMA decision in the fourth quarter of 2026. OS Therapies is also engaging regulators in the U.K., Australia and the U.S. and plans a global confirmatory Phase 3 trial to start in the third quarter of 2026.
Management highlights that peak European sales for OST-HER2 could exceed $300 million annually, with more than $50 million in sales beginning in 2027 if approvals are obtained. OST-HER2 holds multiple special designations, and a future U.S. Biologics License Application could make the company eligible for a Priority Review Voucher that it intends to sell.
OS Therapies Incorporated completed a registered direct offering of 2,505,073 shares of common stock, 1,250,893 pre-funded warrants and 3,755,966 common warrants. Investors paid $1.40 per share and common warrant, or $1.399 per pre-funded warrant and common warrant, generating gross proceeds of $5.25 million and net proceeds of approximately $4.7 million.
The company also issued 187,798 placement agent warrants with a $1.54 exercise price. OS Therapies plans to use the cash to fund clinical development, research programs, potential acquisitions, and general corporate purposes, and expects an additional $4 million in non-dilutive VAT and R&D refunds via its U.K. subsidiary.
OS Therapies Incorporated is offering 2,505,073 shares of common stock together with common warrants and, in lieu of some shares, pre-funded warrants to purchase up to 1,250,893 shares, plus common warrants to purchase up to 3,755,966 shares; placement agent warrants to purchase up to 187,798 shares are also included. The combined public offering price for each share and accompanying common warrant is $1.40; pre-funded warrants plus common warrant are priced at $1.399. The offering contemplates up to 5,006,859 shares of common stock underlying pre-funded warrants and common warrants in the aggregate. Net proceeds are estimated at approximately $4.7 million after fees and expenses, and delivery is expected on or about April 2, 2026. The securities are being placed on a best efforts basis by Ceros Financial Services, Inc., and the pre-funded warrants and common warrants will not be listed for trading.
OS Therapies Incorporated filed a prospectus supplement covering the resale of up to 10,529,417 shares of its common stock by certain selling stockholders. The supplement forms part of the company’s previously effective Form S-3 shelf registration statement. An accompanying Form 8-K provides counsel Olshan Frome Wolosky LLP’s legal opinion on the validity of these shares, filed as Exhibit 5.1, along with the related consent.
OS Therapies registered 10,529,417 shares of common stock for resale by selling stockholders pursuant to a prospectus supplement dated March 31, 2026.
The registered shares consist of 2,622,774 shares issuable upon exercise of 2026 Warrants, 1,666,667 shares issuable upon exercise of Bridge Warrants and 6,239,976 shares issuable upon conversion of Bridge Notes. The company will receive no proceeds from resale by selling stockholders; it will receive proceeds only if outstanding warrants are exercised for cash.
OS Therapies Incorporated files its annual report as a clinical-stage biopharmaceutical company focused on Osteosarcoma and other solid tumors. Its lead candidate OST-HER2 showed improved two‑year overall survival versus historical controls and is being advanced toward potential FDA and European regulatory submissions.
The company has raised capital through PIPE, at-the-market, warrant inducement and bridge financings, but has incurred recurring losses, faces substantial doubt about its ability to continue as a going concern, and will need additional funding to complete development, obtain approvals and build commercialization capabilities.
OS Therapies Incorporated entered into a private placement on March 4, 2026, issuing 10.0% original issue discount unsecured convertible promissory notes and accompanying warrants to accredited investors for aggregate gross cash proceeds of $2,000,000.
The notes have an aggregate principal amount of $2,200,000, bear 4% annual interest, and mature on March 4, 2027, with both principal and accrued interest convertible into equity under mandatory and voluntary conversion features, including a 10‑day volume‑weighted price discount mechanism and anti‑dilution adjustments.
Investors also received warrants to purchase up to 1,666,667 common shares at an exercise price of $1.40 per share, based on an average prior trading price of $1.32, with 4.99% or 9.99% ownership caps and a 19.99% overall issuance limit unless stockholders approve more. Net proceeds are earmarked for clinical development, research and development, and general corporate purposes, and the company agreed to restrictive debt covenants, limitations on variable‑price financings, and to register the underlying shares for resale on a Form S‑3 or Form S‑1.
McKean-Dieser Avril Suzette reported acquisition or exercise transactions in a Form 4 filing for OSTX. The filing lists transactions totaling 50,000 shares. Following the reported transactions, holdings were 50,000 shares.