Quantum Biopharma Ltd. (QNTM) updates 6-K with ATM deal termination

Rhea-AI Filing Summary

Quantum Biopharma Ltd. filed an amended foreign issuer report to add a previously issued press release as an exhibit. The release announces the termination of its October 31, 2025 at-the-market offering agreement with H.C. Wainwright & Co., and is described in the exhibit index as relating to the closing of a private placement and a corporate update. Aside from furnishing this exhibit, the company states that the original report’s disclosures are unchanged.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K/A

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16

OF THE SECURITIES EXCHANGE ACT OF 1934

For the month of December 2025

Commission File Number: 001-39152

QUANTUM BIOPHARMA LTD.

(Registrant)

1 Adelaide Street East, Suite 801

Toronto, Ontario M5C 2V9

(Address of Principal Executive Offices) 

Indicate by check mark whether the Registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F  ☒            Form 40-F  ☐

Indicate by check mark if the Registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1):  ☐

Indicate by check mark if the Registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7):  ☐

EXPLANATORY NOTE

On December 8, 2025, Quantum Biopharma Ltd. (the "Company") furnished a report on Form 6-K, Accession No. 0001753926-25-001860 (the "Original Report"). On December 10, 2025, the Company issued a press release (the “Press Release”) announcing the termination of the At The Market Offering Agreement entered into on October 31, 2025 with H.C. Wainwright & Co., LLC. This Amendment No. 1 to the Original Report (this "Amendment") is being furnished solely to furnish the Press Release as Exhibit 99.1. Except as specifically described in this explanatory note, this Amendment does not reflect events that may have occurred subsequent to the original submission date and does not modify or update in any way the disclosures made in the Original Report.

SIGNATURES

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, thereunto duly authorized.

				QUANTUM BIOPHARMA LTD.
				(Registrant)
Date December 11, 2025				By		/s/ Donal Carroll
						Donal Carroll
						Chief Financial Officer

EXHIBIT INDEX

Exhibit		Description of Exhibit
99.1		Press Release dated December 10, 2025 – Quantum Biopharma announces closing of private placement & provides corporate update

FAQ

What did Quantum Biopharma Ltd. (QNTM) file in this Form 6-K/A?

Quantum Biopharma Ltd. filed an amended foreign private issuer report to furnish a press release as Exhibit 99.1 to a previously submitted Form 6-K.

What is the main purpose of Quantum Biopharma’s 6-K amendment?

The amendment is being furnished solely to add the press release issued on December 10, 2025 as an exhibit to the original Form 6-K report.

Which agreement did Quantum Biopharma (QNTM) terminate according to the press release?

The press release announces the termination of the At The Market Offering Agreement entered into on October 31, 2025 with H.C. Wainwright & Co., LLC.

Does this 6-K/A change any of Quantum Biopharma’s previous disclosures?

The company states that, except as described in the explanatory note, the amendment does not modify or update the disclosures made in the original report.

How is the new Quantum Biopharma press release described in the exhibit index?

The exhibit index describes Exhibit 99.1 as a press release dated December 10, 2025 in which Quantum Biopharma announces the closing of a private placement and provides a corporate update.

Who signed the amended report for Quantum Biopharma Ltd. (QNTM)?

The amended report was signed on behalf of Quantum Biopharma Ltd. by Donal Carroll, Chief Financial Officer, dated December 11, 2025.