Every 8-K that OS Therapies Incorporated (OSTX) has filed with the SEC in the last 24 months is listed below, newest first, and each one links through to the document itself with the summary and the scores our analysis gives it.
A 8-K covers material events a company has to report between its quarterly reports, so if you follow OSTX and want that one kind of document rather than the whole filing history, this is the page to keep. The company's other filings, of every form, are on the full OSTX filings page.
OS Therapies (OSTX) appointed Francis (Frank) Knuettel II as Chief Financial Officer and Kerry Clem as Chief Commercial Officer, effective September 29, 2026. Christopher P. Acevedo ceased serving as CFO and will continue providing services as a consultant. Both executives have three-year initial employment terms and $300,000 annual base salaries. Knuettel’s salary increases to $360,000 following a qualifying material transaction occurring after the date 30 days following his employment’s effective date. Clem’s awards, subject to board approval and award terms, include options for 700,000 common shares and 200,000 RSUs.
Clem will lead U.S., U.K. and European commercialization strategy and launch planning for investigational Herlystic; potential U.S. market entry is subject to regulatory approval. OS Therapies targeted an MHRA application submission for early in the fourth quarter of 2026, with timing and outcomes subject to regulatory review and other conditions. The company reports receiving over $3 million in non-dilutive capital from VAT refunds and accruing over $7 million in R&D tax credits, which will begin flowing to its U.K. subsidiary; funds are earmarked for R&D. Its largest vendors agreed to defer the majority of outstanding accounts payable until the second quarter of 2027.
OS Therapies Inc (OSTX) reported that on September 10, 2026 it filed a prospectus supplement with the SEC covering the resale of up to 5,874,094 shares of its common stock by selling stockholders under an existing Form S-3 registration statement. The supplement relates to a shelf registration originally filed on August 8, 2025 and declared effective on August 25, 2025. OS Therapies also provided a legal opinion from its counsel, Olshan Frome Wolosky LLP, regarding the validity of the shares, which is furnished as Exhibit 5.1 to this report.
OS Therapies Inc (OSTX) reported results of its 2026 annual stockholder meeting held on September 9, 2026. Stockholders approved and adopted the Amended and Restated 2023 Incentive Compensation Plan, which is filed as an exhibit and replaces the prior version of the plan. Directors including Paul A. Romness and five other nominees were elected, with each receiving over 7.3 million votes in favor. A separate proposal, which received 25.7 million votes for and 340,644 against, was also approved. Quorum was achieved with 26,059,902 of 46,205,601 common shares represented in person or by proxy.
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 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 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 filed an amendment to a prior current report to add a missing exhibit related to a previously disclosed private placement. The amendment, dated June 30, 2026, attaches a side letter between OS Therapies and Leonite Fund I, LP as Exhibit 10.3.
The original report, filed on July 2, 2026, had already described the private placement and included the main agreements such as the senior secured convertible promissory note, securities purchase agreement, and pledge and security agreement by reference. This amendment does not change any of those disclosures and should be read together with the original filing.
OS Therapies entered a financing deal for a senior secured convertible note of up to $10,000,000, plus a warrant to buy 1,750,000 shares and 275,000 commitment shares, to support clinical development, regulatory work and general corporate needs. The first $1,600,000 tranche, with a 7.5% original issue discount and 9% annual interest, is expected to fund in early July, with additional tranches at the investor’s discretion. The note converts at $2.05 per share and is subject to a 19.99% exchange cap and 4.99%–9.99% ownership limits, alongside broad anti‑dilution protections and restrictive covenants. OS Therapies also granted a five‑year warrant at a $2.85 exercise price and pledged a first‑priority security interest in most assets, excluding intellectual property itself but including related payment rights. Separately, the company added experienced oncology leader Dr. Craig Eagle to its board and highlighted an additional $10 million line of credit backed by U.K. tax credits, supporting its plan to fund OST‑HER2 programs and maintain cash runway into 2027.
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 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 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.
OS Therapies Incorporated updated investors on its ongoing warrant inducement transaction. The company previously entered into agreements with fewer than 10 accredited investors holding existing warrants to purchase up to 5,382,148 shares of common stock. These investors were offered the opportunity to exercise, or pre-fund the exercise of, their existing warrants for cash at a reduced exercise price of $1.40 per share, or $1.399 per share in the case of pre-funding. In return, the company agreed to issue new common stock purchase warrants to purchase up to an aggregate of 5,382,148 shares at an exercise price of $1.40 per share, subject to adjustment. The company has now extended the inducement offering period from its original expiration at 11:59 p.m. Eastern time on February 10, 2026, to 11:59 p.m. Eastern time on March 2, 2026, giving holders additional time to participate.
OS Therapies Incorporated entered into warrant inducement offer letters with fewer than 10 accredited investors holding existing warrants to purchase up to 5,382,148 shares of common stock. The investors agreed to exercise these existing warrants for cash at a reduced exercise price of $1.40 per share, and in return the company will issue new warrants to purchase up to 5,382,148 additional shares at the same exercise price, exercisable immediately for five years.
The company engaged an SEC-registered broker-dealer as exclusive solicitation agent and expects aggregate gross proceeds of approximately $7.5 million, before an 8.0% cash fee to the agent and up to $25,000 of expenses. OS Therapies plans to use the net proceeds to support U.S. and international regulatory and pre-commercial efforts for OST-HER2 in osteosarcoma, to help fund spinoff preparations for its OS Animal Health subsidiary, and for general corporate purposes.
The new warrants include beneficial ownership caps of 4.99% or, at the holder’s election, 9.99%, a potential forced exercise feature if the stock trades at or above 300% of the exercise price for 20 consecutive trading days, and a cashless exercise option if a resale registration statement is not effective. The company agreed to file a resale registration statement for shares issuable upon exercise of the new warrants within 30 days of closing.
OS Therapies (OSTX) reported results of its 2025 annual meeting and stockholders approved an amendment to the company’s 2023 Incentive Compensation Plan. The meeting was held on October 21, 2025, with 20,516,482 shares present in person or by proxy out of 31,998,288 shares entitled to vote, establishing a quorum.
Votes were recorded on director nominees and other proposals as detailed, and the amended plan text was filed as Exhibit 10.1. Routine meeting items, including proposals receiving broker non-votes, were also tallied.
OS Therapies (OSTX) filed an 8-K announcing two items. First, the company furnished an investor presentation, available on its website and attached as Exhibit 99.1.
Second, the company adjourned its 2025 annual meeting held on October 14, 2025, to allow additional time to solicit proxies. The meeting will reconvene at 10:00 a.m. Eastern time on October 21, 2025, in a virtual format at https://meeting.vstocktransfer.com/OSTHERAPIESOCT25. Based on the preliminary tabulation of votes received, the Issuance Proposal, the Charter Amendment Proposal and the Auditor Ratification Proposal received the requisite votes for approval. The record date remains August 20, 2025. Stockholders of record who have not voted are encouraged to do so by October 20, 2025 at 11:59 p.m. Eastern time. Proxies previously submitted will be voted at the reconvened meeting unless properly revoked.
OS Therapies Incorporated filed a Form 8-K describing a new prospectus supplement that is part of its effective Form S-3 shelf registration. The prospectus supplement covers the resale from time to time of up to 4,373,043 shares of OS Therapies common stock by selling stockholders named in the supplement.
The company used this report to provide investors with the legal opinion from its counsel, Olshan Frome Wolosky LLP, on the validity of these shares, which is filed as Exhibit 5.1, along with the related consent and the cover page interactive data file.
OS Therapies Incorporated closed a second warrant exercise inducement and exchange offer, raising gross proceeds of approximately $3,777,808. Remaining holders of existing warrants exercised for cash warrants to purchase an aggregate of 3,373,043 shares of common stock. In return, the company issued new common stock purchase warrants for up to 3,373,043 additional shares at an exercise price of $3.00 per share, exercisable immediately for five years.
The company will pay a 1.5% cash fee on gross proceeds to its warrant solicitation agent. It plans to use net proceeds primarily to accelerate commercial preparations following OST-HER2 in preventing or delaying recurrent pulmonary metastatic osteosarcoma in the United States, and for general corporate purposes. The new warrants include ownership caps of 4.99% or 9.99%, price-adjustment features for future lower-priced issuances, potential forced exercise if the stock trades at 300% of the exercise price, and cashless exercise if resale registration is not effective.
OS Therapies Incorporated reported that it has terminated its Equity Purchase Agreement with Square Gate Capital Master Fund, LLC — Series 3. This agreement had allowed the company, subject to conditions, to sell up to $15.0 million of its common stock to Square Gate as a potential source of equity capital.
The company’s notice to terminate was delivered on August 25, 2025, and the termination became effective on August 26, 2025. At the time of termination, there were no outstanding borrowings, no pending advance notices, and no shares of common stock remaining to be issued under the agreement. Neither party owed termination fees or other payments in connection with ending the arrangement.
The company also issued a press release on August 25, 2025, to publicly announce the termination of the Equity Purchase Agreement.
OS Therapies Incorporated filed a Form 8-K disclosing a material event via a press release issued on August 19, 2025. The filing identifies the company’s common stock as having a par value of $0.001 per share and trading under the ticker OSTX on the NYSE American. The document is signed by Paul A. Romness, MPH, President and Chief Executive Officer.
The submission includes the cover page interactive data reference and checkboxes for Rule 425 and soliciting/pre-commencement communications, though none of those boxes are marked. The filing therefore publicly documents that a press release was issued and that the company formally reported a material event to the market on the date shown.
OS Therapies Incorporated submitted a Form 8-K reporting an amendment to its amended and restated bylaws titled "Amendment No. 1 to the Amended and Restated Bylaws of OS Therapies Incorporated". The filing is dated August 15, 2025 and is signed by Paul A. Romness, MPH, President and Chief Executive Officer. The company’s common stock trades under the ticker OSTX on NYSE American.
The 8-K provides the title of the bylaw amendment but does not include the text or a summary of the changes in the excerpt provided, so no specific governance changes, clauses, or operational effects can be described from the available content.
OS Therapies (NYSE:OSTX) filed an 8-K reporting the second closing of its June 2025 warrant-exercise inducement.
Holders exercised 550,004 existing $1.12 warrants for cash, delivering $616,000 gross proceeds. In exchange, the company issued 550,004 new five-year warrants exercisable immediately at $3.00 per share.
Main terms:
- Anti-dilution repricing to future issuance level, but not below $1.00
- 4.99% (optionally 9.99%) ownership cap
- Forced exercise if price ≥300% of strike for 20 days
- Cashless exercise when resale registration is unavailable
OSTX must file a resale Form S-3 within 30 days and obtain SEC effectiveness within 60–90 days. Including the first closing announced 24 June (1.57 M shares), the inducement has raised roughly $2.4 million and created 2.12 million new warrants.
OS Therapies Incorporated (NYSE American: OSTX) filed an 8-K to disclose a warrant-exercise inducement designed to raise up to $8 million in gross cash proceeds. The company has entered into Inducement Offer Letters with holders of 1,574,288 outstanding common-stock warrants that currently carry a $1.12 exercise price. In exchange for the holders exercising these warrants for cash during the June 20–July 10, 2025 �Inducement Period,� OSTX will issue an equal number of New Warrants priced at $3.00 per share and exercisable immediately for five years.
The company has retained an SEC-registered, FINRA-member broker as exclusive solicitation agent; it will receive a 5.0 % cash fee on total proceeds plus reimbursement of up to $15,000 in expenses. Assuming full participation, OSTX expects to receive roughly $8 million in gross proceeds before fees and expenses.
Use of proceeds: management plans to fund U.S. and international regulatory and pre-commercial activities aimed at securing marketing authorisations for OST-HER2 in preventing or delaying recurrent, fully resected, lung-metastatic osteosarcoma, and for general corporate purposes.
Key terms of the New Warrants:
- Exercise price: $3.00; immediately exercisable; five-year term.
- Anti-dilution: price resets to the lower of any future equity issuance price or $1.00.
- Beneficial-ownership cap: 4.99 % (optionally 9.99 %) unless 61-day prior notice is given.
- Forced exercise allowed if OSTX trades ≥300 % of exercise price for 20 consecutive trading days, subject to equity conditions.
- Cashless exercise permitted if resale registration is unavailable.
- Fundamental-transaction protection via Black-Scholes cash-out or assumption by successor.
Registration: Existing Warrant shares are already covered by effective S-1 registrations (333-284631 & 333-287569). OSTX will file a resale registration statement for the New Warrant shares within 30 days of the final closing and seek SEC effectiveness within 60–90 days thereafter.
The securities are being issued under Section 4(a)(2) and Rule 506(b) of Regulation D, constituting an unregistered private placement.