OS Therapies Inc SEC Filings

OS Therapies Inc (OSTX) entered into an Open Market Sale Agreement with Jefferies LLC to establish an “at the market offering” program for its common stock. Under a related prospectus supplement to its existing Form S-3 shelf registration, the company may offer and sell shares with an aggregate offering price of up to $75 million through or to Jefferies.

Sales will be made from time to time as “at the market offerings” under Rule 415(a)(4), in block trades, on the Principal Market, or into other existing trading markets, with Jefferies earning a 3.0% commission on the company’s aggregate gross proceeds. OS Therapies will also reimburse Jefferies for certain legal fees up to $100,000. The agreement can be suspended or terminated by either party with notice, and it includes customary representations, covenants, and indemnification provisions.

OS Therapies states that any net proceeds from the ATM program, if raised, are intended to fund clinical development activities and trials, advance research and development programs, and potentially acquire or invest in complementary technologies, product candidates, or businesses, although it currently has no definitive commitments for such acquisitions or investments.

OS Therapies Inc (OSTX) is registering an at‑the‑market offering of up to $75,000,000 of common stock under a Sales Agreement with Jefferies LLC, which will receive a 3.0% commission on gross proceeds. Shares may be sold from time to time on the NYSE American, where the stock closed at $1.58 on August 20, 2026.

At an assumed price of $1.58, this would imply up to 47,468,354 new shares, compared with 46,470,790 shares outstanding as of August 20, 2026, for a potential total of 93,939,144 shares, excluding other convertible and exercisable securities. The company plans to use proceeds to fund clinical development and regulatory activities for OST‑HER2 and its OST‑tADC platform, advance R&D, pursue complementary acquisitions or investments, and for working capital and general corporate purposes.

The company discloses a significant net tangible book value deficit as of June 30, 2026, and its auditor’s report includes an explanatory paragraph regarding its ability to continue as a going concern. The dilution section illustrates that investors buying in this offering at $1.58 would experience immediate dilution of $0.98 per share based on pro forma, as adjusted figures.

OS Therapies Incorporated is a clinical-stage biotech developing OST-HER2 for osteosarcoma and other HER2-positive tumors. For the six months ended June 30, 2026, it reported a net loss of $19.0 million, driven mainly by a sharp increase in research and development expenses to $13.4 million and consulting fees tied to regulatory preparations.

Total assets were $9.9 million, including a new $3.1 million VAT receivable, while cash was only $205,035 and stockholders’ deficit widened to $(11.9) million. Operating activities used $10.1 million of cash, largely offset by $10.0 million from warrant exercises, convertible notes and an April 2026 registered direct equity offering that raised about $4.8 million net. Management concluded that low cash, ongoing losses and an expected $24.0 million in vendor and regulatory costs raise substantial doubt about the company’s ability to continue as a going concern, despite an August 10, 2026 secured note financing providing approximately $4.7 million net and access to additional borrowings.

Clinically, the Phase IIb trial of OST-HER2 in recurrent osteosarcoma met its primary endpoint and showed statistically significant overall-survival benefits versus historical controls at two and 2.5 years, supporting planned BLA and European conditional MAA submissions.

OS Therapies Incorporated entered into a private financing with institutional investors for senior secured convertible promissory notes of up to $10,000,000, split into a $5,000,000 first tranche funded on August 10, 2026 and an optional second tranche of up to $5,000,000 at each purchaser’s discretion.

For the initial $5,000,000 tranche, investors received notes with aggregate principal of $5,405,405.42, 600,000 common shares, pre-funded warrants for up to 900,000 shares, and five-year warrants for up to 1,500,000 shares. A prior $2,200,000 bridge note converted into an additional note, pre-funded warrant and warrant. The notes bear 9.0% annual interest with a one-year minimum, mature nine months after funding, and are convertible at $2.05 per share, subject to a 4.99%–9.99% beneficial ownership cap.

The notes are secured by a first-priority lien on substantially all assets (excluding intellectual property itself but including related payment rights) and include strict negative covenants, default remedies up to 125% of outstanding obligations plus higher default interest and a $10,000 monthly monitoring fee. Warrants from the first tranche are exercisable at $2.85 per share through August 10, 2031, and the company agreed to file a resale registration statement within 30 days of August 10, 2026.

OS Therapies Incorporated entered into a Leonite Settlement Agreement under which it agreed to pay Leonite Fund I, LP $1,900,000 in cash and issue 500,000 common shares by August 7, 2026 in full satisfaction of all obligations under a senior secured convertible note with up to $10,000,000 in principal. Upon closing, the Leonite Note and conversion rights will be cancelled, a warrant for 1,750,000 shares at $2.85 per share will terminate unexercised, 275,000 previously issued commitment shares will be surrendered for cancellation, and all related security interests and liens on the company’s and subsidiaries’ assets will be released.

To fund the settlement, OS Therapies issued a bridge convertible promissory note with $2,200,000 principal for a purchase price of $2,190,000 to an accredited investor; the note bears no interest, matures on September 1, 2026, and will automatically convert into securities of a future private offering of original issue discount promissory notes, if completed. The company used proceeds on August 3, 2026 to make the settlement cash payment and plans to apply remaining funds to working capital, while the settlement shares will be issued under an effective Form S-3 shelf registration and related prospectus supplement.

OS Therapies Incorporated is registering and issuing 500,000 shares of common stock to Leonite Fund I, LP as part of the consideration under a July 31, 2026 settlement agreement resolving obligations related to a prior secured financing. The company will receive no cash proceeds; the shares are non‑cash consideration alongside a $1,900,000 cash payment funded via an August 2026 bridge note. Upon Leonite’s receipt of both the cash payment and these shares, a senior secured convertible note with up to $10,000,000 in principal, the related Leonite warrant and security interests will be extinguished, and previously assigned assets will revert to OS Therapies’ subsidiary free of Leonite’s lien. Shares outstanding are expected to be 46,125,825 after issuance, and the company estimates dilution to Leonite of $1.85 per share based on an assumed offering price of $1.60 and pro forma net tangible book deficit as of March 31, 2026.

OS Therapies Incorporated terminated its At Market Issuance Sales Agreement with B. Riley Securities, Inc. and JonesTrading Institutional Services LLC. The agreement, dated August 8, 2025, allowed the company to offer and sell common stock from time to time with an aggregate offering price of up to $18,000,000.

The company had sold an aggregate of 282,679 shares of common stock for aggregate gross proceeds of approximately $530,162 under the agreement and related prospectus supplement, leaving approximately $17,469,838 unsold. The termination notice was delivered on July 23, 2026 and became effective on July 28, 2026. No termination fees or other payments were due by either party, and no further shares may be offered or sold under this program.

OS Therapies Incorporated is calling a virtual 2026 annual meeting on September 9, 2026 to elect six directors, amend and restate its 2023 Incentive Compensation Plan, and ratify MaloneBailey, LLP as independent auditor for the year ending December 31, 2026.

The amended plan would increase shares available for equity awards by 5,000,000, bringing the total plan pool to 15,000,000 shares, remove per-person award limits, and update tax provisions, while 1,575,463 shares remained available for new grants under the existing plan as of July 21, 2026. As of that date, there were 45,538,101 common shares and 392,500 Series A preferred shares outstanding, with holders voting together as a single class. The proxy also outlines board and committee structure, director independence, executive roles, 2025 executive pay led by CEO Paul A. Romness at $1,942,168, and 2025 audit fees to MaloneBailey totaling $309,633.