Fulcrum Therapeutics, Inc.

Item 1.01. Entry into a Material Definitive Agreement. Merger Agreement On August 16, 2026, Fulcrum Therapeutics, Inc., a Delaware corporation (“Fulcrum”) entered into an Agreement and Plan of Merger (the “Merger Agreement”) by and among Fulcrum, Fusion Merger Sub I, Inc., a Delaware corporation and a wholly owned subsidiary of Fulcrum, (“Merger Sub I”), Fusion Merger Sub II, LLC, a Delaware limited liability company and a wholly owned subsidiary of Fulcrum, (“Merger Sub II”), and Slate Medicines, Inc., a Delaware corporation (“Slate”), pursuant to which, and subject to the satisfaction or waiver of the conditions set forth in the Merger Agreement, among other things, Merger Sub I will merge with and into Slate, with Slate surviving the merger as the surviving corporation (the “First Merger”), and as part of the same overall transaction, Slate will merge with and into Merger Sub II, with Merger Sub II continuing as a wholly owned subsidiary of Fulcrum and the surviving entity of the merger (the “Second Merger” and together with the First Merger, the “Merger”). The Merger is intended to qualify for federal income tax purposes as a tax-free reorganization. Subject to the terms and conditions of the Merger Agreement, at the effective time of the Merger (the “Effective Time”), (a) each then-outstanding share of Slate’s common stock, par value $0.00001 per share (“Slate Common Stock”) will be converted into the right to receive a number of shares of Fulcrum’s common stock, par value $0.001 per share (“Fulcrum Common Stock”), based on a ratio calculated in accordance with the Merger Agreement (the “Exchange Ratio”), (b) each then-outstanding option to purchase Slate Common Stock will be assumed by Fulcrum, subject to adjustment as set forth in the Merger Agreement, and (c) each then-outstanding warrant to purchase Slate Common Stock will be assumed by Fulcrum, subject to adjustment as set forth in the Merger Agreement. Under the Exchange Ratio formula in the Merger Agreement, upon the closing of the Merger (the “Closing”), on a pro forma basis and based upon the number of shares of Fulcrum Common Stock expected to be issued in connection with the Merger and the Concurrent Investment (as defined below), pre-Merger Slate stockholders (other than the Investors (as defined below)) are expected to own approximately 55.9% of the combined company on a fully-diluted basis, the Investors are expected to own approximately 39.1% of the combined company on a fully-diluted basis, and pre-Merger Fulcrum stockholders will own approximately 5.0% of the combined company on a fully-diluted basis (after giving effect to the Concurrent Investment and excluding any shares reserved for future grants under the 2026 Equity Incentive Plan and the 2026 ESPP, each as defined in the Merger Agreement). The percentage of the combined company that each party’s stockholders will own following the Closing is subject to certain adjustments as described in the Merger Agreement, including the amount of Fulcrum’s net cash at the Closing. The Exchange Ratio assumes (i) a valuation for Fulcrum of $31.3 million, subject to adjustment based on the amount of net cash of Fulcrum at the Closing, and (ii) a valuation for Slate of $350.0 million, exclusive of any proceeds received in connection with the Concurrent Investment; and (iii) a $245.0 million Concurrent Investment. The Exchange Ratio is also based on the relative capitalization of each of Fulcrum and Slate, for which, for the purposes of calculating the Exchange Ratio, the shares of Fulcrum Common Stock underlying Fulcrum stock options outstanding immediately prior to the Effective Time with an exercise price per share of less than or equal to $7.00 (as adjusted as provided in the Merger Agreement) will be deemed outstanding, and all shares of Slate Common Stock underlying outstanding Slate stock options, warrants, and other derivative securities will be deemed outstanding. The unexercised and outstanding Fulcrum stock options will accelerate in full as of immediately prior to the Effective Time. Each such stock option with an exercise price per share greater than $7.00 (prior to giving effect to the Cash Dividend and Nasdaq Reverse Stock Split (as defined in the Merger Agreement)) that is not exercised as of immediately prior to the Effective Time shall be cancelled at the Effective Time for no consideration. All Fulcrum stock options with an exercise price per share less than or equal to $7.00 (prior to giving effect to the Cash Dividend and Nasdaq Reverse Stock Split (as defined in the Merger Agreement)) will continue to be subject to the same terms and conditions after the Effective Time as were applicable to such stock option as of immediately prior to the Effective Time. In addition, pursuant to the Merger Agreement, the vesting of each outstanding and unvested Fulcrum restricted stock unit award will be accelerated in full, effective as of immediately prior to the Effective Time, contingent on the occurrence of the Closing, and each holder thereof will receive shares of Fulcrum Common Stock in settlement of such awards immediately prior to the Effective Time. In addition, in connection with the Closing, Fulcrum expects to declare a cash dividend to the pre-Merger Fulcrum stockholders of $270 million in the aggregate (the “Cash Dividend”), provided such amount is subject to adjustment as set forth in the Merger Agreement. In connection with the Merger, Fulcrum will seek the approval of its stockholders to, among other things, (a) issue the shares of Fulcrum Common Stock issuable in connection with the Merger pursuant to the rules of The Nasdaq Stock Market LLC (“Nasdaq”), (b) adopt the 2026 Equity Incentive Plan and the 2026 ESPP (as each is defined in the Merger Agreement), and (c) amend its restated certificate of incorporation, as amended, to change Fulcrum’s name to “Slate Medicines, Inc.” and effect a reverse stock split of Fulcrum Common Stock, at a reverse stock split ratio to be mutually agreed to by Fulcrum and Slate (the “Fulcrum Voting Proposals”). Each of Fulcrum and Slate has agreed to customary representations, warranties and covenants in the Merger Agreement, including, among others, covenants relating to (1) obtaining the requisite approval of their respective stockholders, (2) non-solicitation of alternative acquisition proposals, (3) the conduct of their respective businesses during the period between the date of signing the Merger Agreement and the Closing, (4) Fulcrum using commercially reasonable efforts to maintain the existing listing of the Fulcrum Common Stock on Nasdaq and cause the shares of Fulcrum Common Stock to be issued in connection with the Merger to be approved for listing on Nasdaq prior to the Closing and (5) Fulcrum filing with the U.S. Securities and Exchange Commission (the “SEC”) and causing to become effective a registration statement on Form S-4 to register the shares of Fulcrum Common Stock to be issued in connection with the Merger (the “Registration Statement”). Consummation of the Merger is subject to certain closing conditions, including, among other things, (1) approval by Fulcrum stockholders of the Fulcrum Voting Proposals, (2) approval by the requisite Slate stockholders of the adoption and approval of the Merger Agreement and the transactions contemplated thereby, (3) the waiting period under the U.S. Hart Scott Rodino Antitrust Improvements Act of 1976, as amended, having expired or been terminated, (4) Nasdaq’s approval of the listing of the shares of Fulcrum Common Stock to be issued in connection with the Merger, (5) the effectiveness of the Registration Statement, (6) the effectiveness of the Nasdaq Reverse Stock Split, (7) Fulcrum’s net cash at the Closing being no less than $0, and (8) an executed Purchase Agreement for the Concurrent Investment in full force and effect evidencing cash proceeds of approximately $245.0 million to be received by the combined company immediately prior to or following the Closing. Each party’s obligation to consummate the Merger is also subject to other specified customary conditions, including regarding the accuracy of the representations and warranties of the other party, subject to the applicable materiality standard, and the performance in all material respects by the other party of its obligations under the Merger Agreement required to be performed on or prior to the date of the Closing. The Merger Agreement contains certain termination rights of each of Fulcrum and Slate. Upon termination of the Merger Agreement under specified circumstances, Fulcrum may be required to pay Slate a termination fee of $10 million, and in certain other circumstances, Slate may be required to pay Fulcrum a termination fee of $15 million. At the Effective Time, the board of directors of Fulcrum is expected to consist of five members, all of whom will be designated by Slate. Support Agreements and Lock-Up Agreements Concurrently and in connection with the execution of the Merger Agreement, (i) certain stockholders of Slate (solely in their respective capacities as Slate stockholders) holding approximately 78.65% of the outstanding shares of Slate capital stock have entered into support agreements with Fulcrum and Slate to vote all of their shares of Slate capital stock in favor of the adoption and approval of the Merger Agreement and the transactions contemplated thereby (the “Slate Support Agreements”) and (ii) certain stockholders of Fulcrum holding approximately 1.0% of the outstanding shares of Fulcrum Common Stock have entered into support agreements with Fulcrum and Slate to vote all of their shares of Fulcrum Common Stock in favor of the Fulcrum Stockholder Proposals (the “Fulcrum Support Agreements,” and, together with the Slate Support Agreements, the “Support Agreements”). Concurrently and in connection with the execution of the Merger Agreement, certain executive officers, directors and stockholders of Slate have entered into lock-up agreements (the “Lock-Up Agreements”) pursuant to which, and subject to specified exceptions, they have agreed not to transfer their shares of Fulcrum Common Stock for the 180-day period following the Closing. The preceding summaries of the Merger Agreement, the Support Agreements and the Lock-Up Agreements do not purport to be complete and are qualified in their entirety by reference to the Merger Agreement, the form of Fulcrum Support Agreement, the form of Slate Support Agreement, and the form of Lock-Up Agreement, which are filed as Exhibits 2.1, 10.1, 10.2, and 10.3, respectively, to this Current Report on Form 8-K and which are incorporated herein by reference. The Merger Agreement has been attached as an exhibit to this Current Report on Form 8-K to provide investors and securityholders with information regarding its terms. It is not intended to provide any other factual information about Fulcrum or Slate or to modify or supplement any factual disclosures about Fulcrum in its public reports filed with the SEC. The Merger Agreement includes representations, warranties and covenants of Fulcrum, Slate, Merger Sub I and Merger Sub II made solely for the purpose of the Merger Agreement and solely for the benefit of the parties thereto in connection with the negotiated terms of the Merger Agreement. Investors should not rely on the representations, warranties and covenants in the Merger Agreement or any descriptions thereof as characterizations of the actual state of facts or conditions of Fulcrum, Slate or any of their respective affiliates. Moreover, certain of those representations and warranties may not be accurate or complete as of any specified date, may be modified in important part by the underlying disclosure schedules which are not filed publicly, may be subject to a contractual standard of materiality different from those generally applicable to SEC filings or may have been used for purposes of allocating risk among the parties to the Merger Agreement, rather than establishing matters of fact. Private Placement and Purchase Agreement On August 16, 2026, Slate entered into a Securities Purchase Agreement (the “Purchase Agreement”) with certain existing Slate stockholders and new investors (the “Investors”). Pursuant to the Purchase Agreement, and subject to the terms and conditions thereof, Slate agreed to sell, and the Investors agreed to purchase, immediately prior to the consummation of the Merger, shares of Slate Common Stock (the “Securities”) for an aggregate purchase price of approximately $245 million (collectively, the “Concurrent Investment”). The consummation of the transactions contemplated by such agreements is conditioned on the satisfaction or waiver of the conditions set forth in the Merger Agreement and in the Purchase Agreement. Shares of Slate Common Stock issued pursuant to this financing transaction will be converted into shares of Fulcrum Common Stock in accordance with the Exchange Ratio and the Merger Agreement. The Concurrent Investment is exempt from registration pursuant to Section 4(a)(2) of the Securities Act of 1933, as amended (the “Securities Act”), and/or Regulation D promulgated thereunder, as a transaction by an issuer not involving a public offering. The Investors have acquired the Securities for investment only and not with a view to or for sale in connection with any distribution thereof, and appropriate legends have been affixed to the Securities issued in this transaction. The foregoing summary of the Purchase Agreement does not purport to be complete and is qualified in its entirety by reference to the form of Purchase Agreement, which is filed as Exhibit 10.4 to this Current Report on Form 8-K and incorporated herein by reference. Registration Rights Agreement In connection with the Purchase Agreement, on August 16, 2026, Slate entered into a Registration Rights Agreement (the “Registration Rights Agreement”) with the Investors. Pursuant to the Registration Rights Agreement, Slate agreed to cause to be prepared and filed by the combined company a resale registration statement with the SEC within 30 business days following the closing of the Concurrent Investment. Slate (and for periods of time after the Closing, the combined company) will use commercially reasonable efforts to cause this registration statement to be declared effective by the SEC within five business days of notification that the SEC will not review the registration statement (or within 60 calendar days if the SEC reviews the registration statement). Slate also agreed to, among other things, indemnify the Investors, their officers, directors, members, employees and agents, successors and assigns under the registration statement from certain liabilities and pay all fees and expenses (excluding any legal fees of the selling holder(s), and any underwriting discounts and selling commissions) incident to Slate’s obligations under the Registration Rights Agreement. The foregoing summary of the Registration Rights Agreement does not purport to be complete and is qualified in its entirety by reference to the form of Registration Rights Agreement, which is filed as Exhibit 10.5 to this Current Report on Form 8-K and incorporated herein by reference.

Item 3.02. Unregistered Sales of Equity Securities. To the extent required by this Item, the information included in Item 1.01 of this Current Report on Form 8-K is incorporated herein by reference. The shares to be issued by Slate in the Concurrent Investment will be issued in private placements exempt from registration under Section 4(a)(2) of the Securities Act, and/or Regulation D promulgated thereunder, because the offer and sale of such securities does not involve a “public offering” as defined in Section 4(a)(2) of the Securities Act, and other applicable requirements were met. Neither this Current Report on Form 8-K nor any of the exhibits attached hereto is an offer to sell or the solicitation of an offer to buy the Securities or any other securities of Slate or Fulcrum.

Item 5.01. Changes in Control of Registrant. To the extent required by this Item, the information included in Item 1.01 of this Current Report on Form 8-K is incorporated herein by reference.

Item 5.02. Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers. To the extent required by this Item, the information included in Item 1.01 of this Current Report on Form 8-K is incorporated herein by reference.

Item 7.01. Regulation FD Disclosure. On August 17, 2026, Fulcrum and Slate issued a joint press release announcing the execution of the Merger Agreement and the Purchase Agreement. The press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K and incorporated herein by reference, except that the information contained on the websites referenced in the press release is not incorporated herein by reference. Furnished as Exhibit 99.2 hereto and incorporated herein by reference is the investor presentation that will be used by Fulcrum and Slate in connection with the Merger, including during the webcast described below. The information in this Item 7.01, including Exhibits 99.1 and 99.2 attached hereto, 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, or the Exchange Act, except as expressly set forth by specific reference in such filing.