of this Current Report on Form 8-K (including Exhibit 99.1 attached hereto) is intended to be furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such filing.

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 hereunto duly authorized. DISC MEDICINE, INC. Date: June 30, 2026 By: /s/ John Quisel, J.D., Ph.D Name: John Quisel, J.D., Ph.D. Title: President and Chief Executive Officer

Entry into a Material Definitive Agreement. On June 25, 2026, Disc Medicine, Inc. (the “Company”) entered into a First Amendment to Loan Agreement (the “Amendment”) to the Loan and Security Agreement dated as of November 6, 2024 (as amended, the “Loan Agreement”) among the Company, the lender party thereto and Hercules Capital, Inc., as administrative agent and collateral agent (“Hercules”) for the purpose of extending the periods during which future Advances (as defined in the Loan Agreement…

of this Current Report on Form 8-K (including Exhibit 99.1 attached hereto) is intended to be furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such filing.

Costs Associated with Exit or Disposal Activities. On February 26, 2026, the board of directors of Disc Medicine, Inc. (the “Company”) approved, and management began implementing, a restructuring plan (the “Restructuring Plan”) to better align the Company’s workforce with its near-term strategic priorities following the receipt of a complete response letter from the U.S. Food and Drug Administration (“FDA”) on February 13, 2026 with respect to the Company’s New Drug Application for bitopertin…

of this Current Report on Form 8-K (including Exhibit 99.1 attached hereto) is intended to be furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such filing.

Regulation FD Disclosure. On February 17, 2026, Disc Medicine, Inc. (the "Company") will host a previously-announced conference call at 8:00 AM ET to discuss the Complete Response Letter issued by the U.S. Food and Drug Administration on February 13, 2026 with respect to the Company's New Drug Application for bitopertin as a treatment for patients with erythropoietic protoporphyria. An archived webcast will be available following the call for 30 days on the Events & Presentations section of t…

Other Events. On February 13, 2026, the Company received a CRL from the FDA for the Company’s NDA for bitopertin as a treatment for patients with EPP.

Regulation FD Disclosure. On February 13, 2026, Disc Medicine, Inc. (the “Company”) issued a press release announcing that the U.S. Food and Drug Administration ("FDA") issued a Complete Response Letter ("CRL") for the New Drug Application ("NDA") for bitopertin as a treatment for patients with erythropoietic protoporphyria ("EPP"). A copy of the press release and a copy of the CRL are attached as Exhibit 99.1 and Exhibit 99.2, respectively, to this Current Report on Form 8-K and are incorpor…

Results of Operations and Financial Condition. On January 12, 2026, Disc Medicine, Inc. (the “Company”) issued a press release announcing, among other things, that its preliminary unaudited cash, cash equivalents and marketable securities as of December 31, 2025 were approximately $791 million. A copy of the press release is attached as Exhibit 99.1 to this Current Report on Form 8-K. The Company has not yet completed its year-end financial close process for the year ended December 31, 2025.…

of this Current Report on Form 8-K shall be deemed to be furnished and not filed: Exhibit No. Description 99.1 Press release issued by Disc Medicine, Inc. on November 6, 2025, furnished herewith. 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. DISC MEDICINE, INC. Date:…

Entry into a Material Definitive Agreement. On October 20, 2025, Disc Medicine, Inc. (the “Company”) entered into an Underwriting Agreement (the “Underwriting Agreement”) with Jefferies LLC, Leerink Partners LLC, Morgan Stanley & Co. LLC and Cantor Fitzgerald & Co., as representatives of the several underwriters listed on Schedule I thereto (the “Underwriters”) and AI DMI LLC, as a selling stockholder (the “Selling Stockholder”), related to an underwritten offering (the “Offering”) (i) by the…

Other Events. On October 20, 2025, the Company issued a press release announcing the commencement of the Offering. On October 21, 2025, the Company issued a press release announcing that it had priced the Offering. Copies of these press releases are attached hereto as Exhibit 99.1 and Exhibit 99.2, respectively, and are incorporated by reference herein. Cautionary Statement Regarding Forward-Looking Statements This Current Report on Form 8-K contains “forward-looking statements” within the me…

Results of Operations and Financial Condition. On October 20, 2025, Disc Medicine, Inc. (the “Company”) announced that its preliminary unaudited cash, cash equivalents and marketable securities as of September 30, 2025 were approximately $615.9 million. The Company has not yet completed its quarter-end financial close process for the quarter ended September 30, 2025. This estimate of the Company’s cash, cash equivalents and marketable securities as of September 30, 2025 is preliminary, has no…

Director — Mona Ashiya, Ph.D.: Dr. Mona Ashiya resigned from the Board of Directors and related committees.

of this Current Report on Form 8-K shall be deemed to be furnished and not filed: Exhibit No. Description 99.1 Press release issued by Disc Medicine, Inc. on August 7, 2025, furnished herewith. 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. DISC MEDICINE, INC. Date: Au…

Director — Nadim Ahmed: Election of Nadim Ahmed as a director.

of this Current Report on Form 8-K shall be deemed to be furnished and not filed: Exhibit No. Description 99.1 Press release issued by Disc Medicine, Inc. on May 7, 2025, furnished herewith. 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. DISC MEDICINE, INC. Date: May 7…

of this Current Report on Form 8-K shall be deemed to be furnished and not filed: Exhibit No. Description 99.1 Press Release issued by Disc Medicine, Inc. on February 27, 2025. 104 Cover Page Interactive Data File (embedded within the Inline XBRL document). SIGNATURE Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. DISC MEDICINE, INC. Date: Februar…

Entry into a Material Definitive Agreement. On January 22, 2025, Disc Medicine, Inc. (the “Company”) entered into an Underwriting Agreement (the “Underwriting Agreement”) with Jefferies LLC, Leerink Partners LLC, Stifel, Nicolaus & Company, Incorporated and Cantor Fitzgerald & Co. as representatives of the several underwriters listed on Schedule I thereto (the “Underwriters”), related to an underwritten offering (the “Offering”) of (i) 3,918,182 shares of common stock of the Company, par valu…

Other Events. On January 21, 2025, the Company issued a press release announcing the Offering. On January 22, 2025, the Company issued a press release announcing that it had priced the Offering. Copies of these press releases are attached hereto as Exhibit 99.1 and Exhibit 99.2, respectively, and are incorporated by reference herein. Cautionary Statement Regarding Forward-Looking Statements This Current Report on Form 8-K contains “forward-looking statements” within the meaning of the Private…

Other Events. On January 21, 2025, the Company announced positive feedback from its Type C meeting with the FDA to discuss the APOLLO post-marketing confirmatory trial for bitopertin in EPP and XLP. The meeting resulted in alignment on the design of the APOLLO post-marketing confirmatory trial. Key features include: • Co-primary endpoints of average monthly total time in sunlight without pain between 10:00 and 18:00 during the last month of the 6-month treatment period and percent change from…

Termination of a Material Definitive Agreement. On November 15, 2024, the Company delivered written notice to Jefferies LLC (“Jefferies”) that it was terminating Open Market Sale Agreement SM (the “Prior Sales Agreement”) dated October 10, 2023, by and between the Company and Jefferies, as amended by Amendment No. 1 to the Prior Sales Agreement dated December 5, 2023 and that no further offers or sales of shares of common stock would be made pursuant to the prospectus supplement filed with th…

Entry into a Material Definitive Agreement. On November 15, 2024, Disc Medicine, Inc. (the “Company”) entered into a Controlled Equity Offering SM Sales Agreement (the “Agreement”) with Cantor Fitzgerald & Co. (“Cantor”), pursuant to which the Company may, from time to time in its sole discretion, issue and sell to or through Cantor, acting as sales agent, shares of the Company’s common stock, par value $0.0001 per share (“common stock”). The issuance and sale, if any, of shares of common sto…

of this Current Report on Form 8-K shall be deemed to be furnished and not filed: Exhibit No. Description 99.1 Press Release issued by Disc Medicine, Inc. on November 12, 2024 104 Cover Page Interactive Data File (embedded within the Inline XBRL document). SIGNATURE Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. DISC MEDICINE, INC. Date: November…