OS Therapies details resale of 5.9M shares

Q: What did OS Therapies Inc (OSTX) announce in this Form 8-K?

OS Therapies Inc announced 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.

Q: How many OSTX shares are covered by the new prospectus supplement?

The prospectus supplement covers the resale of up to 5,874,094 shares of OS Therapies Inc common stock. These shares may be sold from time to time by the selling stockholders identified in the prospectus supplement.

Q: What registration statement does the OS Therapies (OSTX) prospectus supplement relate to?

The prospectus supplement forms part of OS Therapies Inc’s registration statement on Form S-3 (File No. 333-289443), which was filed with the SEC on August 8, 2025 and declared effective on August 25, 2025.

Q: What legal documents did OS Therapies Inc (OSTX) file with this 8-K?

OS Therapies Inc filed as exhibits a legal opinion from Olshan Frome Wolosky LLP regarding the legality of the shares (Exhibit 5.1) and a related consent from the same firm (Exhibit 23.1), with the consent included in the opinion.

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.

Available on EDGAR 09/10/2026 - 05:28 PM EDT Accepted by SEC EDGAR 09/10/2026 - 05:28 PM EDT

Filing Impact

(High)

Filing Sentiment

(Neutral)How Sentiment works

Sentiment and the balance of points

Rhea-AI Sentiment reads the wording of the document, how positive or negative its language is on a 1 to 5 scale. The balance of points shown with the takes weighs what the document actually discloses, so the two can disagree, for example when a trial that missed its main goal is described in upbeat language.

How Sentiment works How the balance works

Form Type

8-K

Rhea-AI Filing Summary

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.

Filing Explained

The September 10 8-K records registration for the resale of up to 5,874,094 shares by selling stockholders, not a completed sale; the shelf-registration framework creates capacity for future registered sales, so this filing alone does not establish a new company issuance.

8-K Event Classification

2 items: 8.01, 9.01

2 items

Item 8.01 Other Events Other

Voluntary disclosure of events the company deems important to shareholders but not covered by other items.

Item 9.01 Financial Statements and Exhibits Exhibits

Financial statements, pro forma financial information, or exhibit attachments filed with this report.

Key Figures

Shares covered by prospectus supplement: 5,874,094 shares Form S-3 file number: File No. 333-289443 Form S-3 filing date: August 8, 2025 +2 more

5 metrics

Shares covered by prospectus supplement 5,874,094 shares Resale of common stock by selling stockholders under Form S-3

Form S-3 file number File No. 333-289443 Registration statement that the prospectus supplement forms part of

Form S-3 filing date August 8, 2025 Date the Form S-3 registration statement was filed with the SEC

Form S-3 effectiveness date August 25, 2025 Date the Form S-3 registration statement was declared effective

Prospectus supplement and 8-K date September 10, 2026 Date OS Therapies filed the prospectus supplement and this report

Key Terms

prospectus supplement, registration statement on Form S-3, resale, selling stockholders, +1 more

5 terms

prospectus supplement financial

"filed with the U.S. Securities and Exchange Commission a prospectus supplement"

A prospectus supplement is an additional document provided alongside a company's main offering details, offering updated or extra information about a specific financial product being sold. It helps investors understand the latest terms, risks, and details of the investment, similar to how an update or revision clarifies or expands on original instructions, ensuring they have current and complete information before making a decision.

registration statement on Form S-3 regulatory

"forms a part of the Company’s registration statement on Form S-3"

A registration statement on Form S‑3 is a short, standardized filing a qualified public company uses to register new securities with regulators so they can be sold to investors; think of it as a pre-approved, reusable permission slip that speeds up future offerings. It matters to investors because it lets the company raise money more quickly and cheaply — which can fund growth or pay debt — but may also lead to share dilution or change in ownership, so it affects value and liquidity.

resale financial

"covers the resale from time to time of up to 5,874,094 shares"

Resale is the act of selling an item, asset, or security by someone who previously bought it rather than by the original maker or issuer. It matters to investors because resale activity affects how easily an investment can be sold, the price buyers are willing to pay, and the potential profit or loss — like selling a used car: condition, demand and market rules determine what you can get for it.

selling stockholders financial

"by the selling stockholders referenced in the Prospectus Supplement"

Selling stockholders are existing owners of a company's shares who are offering some or all of their holdings for sale, often as part of a public offering or secondary transaction. For investors this matters because such sales increase the number of shares available to buy, can signal how confident current owners are about future prospects, and may put short-term pressure on the stock price similar to more tickets being released for a popular event.

legal opinion regulatory

"to provide the legal opinion of its counsel, Olshan Frome Wolosky LLP"

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What did OS Therapies Inc (OSTX) announce in this Form 8-K?

OS Therapies Inc announced 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.

How many OSTX shares are covered by the new prospectus supplement?

The prospectus supplement covers the resale of up to 5,874,094 shares of OS Therapies Inc common stock. These shares may be sold from time to time by the selling stockholders identified in the prospectus supplement.

What registration statement does the OS Therapies (OSTX) prospectus supplement relate to?

The prospectus supplement forms part of OS Therapies Inc’s registration statement on Form S-3 (File No. 333-289443), which was filed with the SEC on August 8, 2025 and declared effective on August 25, 2025.

Who is selling the OSTX shares covered by the prospectus supplement?

The shares covered by the prospectus supplement are to be sold from time to time by selling stockholders referenced in the prospectus supplement. OS Therapies Inc is not identified as the seller of these shares in this report.

What legal documents did OS Therapies Inc (OSTX) file with this 8-K?

OS Therapies Inc filed as exhibits a legal opinion from Olshan Frome Wolosky LLP regarding the legality of the shares (Exhibit 5.1) and a related consent from the same firm (Exhibit 23.1), with the consent included in the opinion.

When was the OS Therapies (OSTX) Form S-3 declared effective?

OS Therapies Inc’s registration statement on Form S-3 (File No. 333-289443) was declared effective on August 25, 2025 by the SEC, following its original filing on August 8, 2025.

AI-generated analysis. How Rhea-AI works. Not financial advice.

Understanding 8-K Material Events →

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): September 10, 2026

OS THERAPIES INCORPORATED

(Exact name of registrant as specified in its charter)

Delaware

001-42195

82-5118368

(State or other jurisdiction

of incorporation)

(Commission File Number)

(IRS Employer

Identification No.)

115 Pullman Crossing Road, Suite 103

Grasonville, Maryland

21638

(Address of Principal Executive Offices)

(Zip Code)

Registrant’s telephone number, including area code: (410) 297-7793

N/A

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

☐	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of Each Class		Trading Symbol(s)		Name of Each Exchange on Which Registered
Common Stock, par value $0.001 per share		OSTX		NYSE American

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

CURRENT REPORT ON FORM 8-K

OS Therapies Incorporated

September 10, 2026

Item 8.01. Other Events.

On September 10, 2026, OS Therapies Incorporated (the “Company”) filed with the U.S. Securities and Exchange Commission (the “SEC”) a prospectus supplement (the “Prospectus Supplement”), which forms a part of the Company’s registration statement on Form S-3 (File No. 333-289443), which was previously filed with the SEC on August 8, 2025 and declared effective on August 25, 2025. The Prospectus Supplement covers the resale from time to time of up to 5,874,094 shares of the Company’s common stock (the “Shares”) by the selling stockholders referenced in the Prospectus Supplement. The Company is filing this Current Report on Form 8-K to provide the legal opinion of its counsel, Olshan Frome Wolosky LLP, regarding the legality of Shares, which is attached hereto as Exhibit 5.1.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

Exhibit Number		Description
5.1		Opinion of Olshan Frome Wolosky LLP.
23.1		Consent of Olshan Frome Wolosky LLP (included in its opinion filed as Exhibit 5.1).
104		Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	OS THERAPIES INCORPORATED

Dated: September 10, 2026	By:	/s/ Paul A. Romness, MPH
		Name:	Paul A. Romness, MPH
		Title:	President and Chief Executive Officer

Source: View Original Filing on SEC EDGAR

Filing Exhibits & Attachments

4 documents