of this Current Report on Form 8-K, including Exhibit 99.1, is being 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, and shall not be 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.

of this Current Report on Form 8-K, including Exhibit 99.1, is being 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, and shall not be 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.

Other Events. On April 21, 2026, the Company announced results from the 8-week follow-up period of its Phase 2a trial of RAP-219 in focal onset seizures (“FOS”). In the Phase 2a trial, adult patients with FOS received RAP-219 for 8 weeks and then entered an 8-week follow-up period after treatment ended to evaluate the effect of RAP-219 on long episodes (“LEs”) – an objective biomarker of epileptiform activity with >90% median concordance with electrographic seizures in this trial – and clinic…

of this Current Report on Form 8-K, including Exhibit 99.1, is being 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, and shall not be 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.

Other Events. On January 7, 2026, Rapport Therapeutics, Inc. (the “Company”) filed a prospectus supplement (the “Prospectus Supplement”) to the Company’s effective shelf registration statement on Form S-3 (File No. 333-288444) (the “Registration Statement”). The Company filed the Prospectus Supplement for the purpose of registering the offer and sale of shares of its common stock having an aggregate offering price of up to $110,000,000 (the “Shares”) from time to time through or to Leerink Pa…

of this Current Report on Form 8-K, including Exhibit 99.1, is being 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, and shall not be incorporated by reference in any filing under the Securities Act of 1933, as amended (the “Securities Act”), or the Exchange Act, except as expressly set forth by specific reference in such filing.

Entry into a Material Definitive Agreement. On September 9, 2025, Rapport Therapeutics, Inc. (the “Company”) entered into an Underwriting Agreement (the “Underwriting Agreement”) with Goldman Sachs & Co. LLC, Jefferies LLC, TD Securities (USA) LLC and Stifel, Nicolaus & Company, Incorporated (collectively, the “Underwriters”), related to an underwritten public offering (the “Offering”) of 9,615,385 shares (the “Firm Shares”) of the Company’s common stock, par value $0.001 per share (“Common S…

Other Events. Effective September 8, 2025, the Company terminated the sales agreement prospectus (the “ATM Prospectus”) filed with the Company’s registration statement on Form S-3 (File No. 333-288444) (the “Registration Statement”) and related to the shares of the Company’s common stock, par value $0.001 per share (“Common Stock”), issuable pursuant to the Sales Agreement, dated July 1, 2025, by and among the Company, Leerink Partners LLC and Cantor Fitzgerald & Co. (the “Sales Agreement”).…

of this Current Report on Form 8-K, including Exhibit 99.1, is being 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, and shall not be incorporated by reference in any filing under the Securities Act of 1933, as amended (the “Securities Act”), or the Exchange Act, except as expressly set forth by specific reference in such filing.

contains “forward-looking statements” of the Company within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including without limitation, express or implied statements regarding: the clinical development of RAP-219 for the treatment of refractory focal epilepsy, bipolar mania and diabetic peripheral neuropathic pain, including the initiation, timing, progress and results of our ongoing and planned clinical trials; expectations for the activity, tolerability, a…

of this Current Report on Form 8-K, including Exhibit 99.1, is being 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, and shall not be 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.

of this Current Report on Form 8-K, including Exhibit 99.1, is being 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, and shall not be 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.

are based on management’s current expectations and are subject to risks and uncertainties that could negatively affect the Company’s business, operating results, financial condition, and stock value. Factors that could cause actual results to differ materially from those currently anticipated include: risks relating to the Company’s research and development activities, including that interim, topline and preliminary data from our clinical trials that we announce or publish from time to time a…

of this Current Report on Form 8-K, including Exhibit 99.1, is being 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, and shall not be 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.

of this Current Report on Form 8-K, including Exhibit 99.1, is being 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, and shall not be 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.

Entry into a Material Definitive Agreement. On June 6, 2024, Rapport Therapeutics, Inc. (the “Company”) entered into Stock Purchase Agreements (the “Purchase Agreements”) with Sofinnova Venture Partners, XI, L.P. and affiliates of Goldman Sachs & Co. LLC (collectively, the “Purchasers”), including certain investment funds managed by Goldman Sachs & Co. LLC, each of which were existing stockholders of the Company, for the purchase of an aggregate of 1,058,824 shares of its common stock, par va…

The Common Stock issued and sold in the Private Placement has not been registered under the Securities Act, or applicable state securities laws, and was issued and sold pursuant to Section 4(a)(2) of the Securities Act. Each of the Purchasers has represented that it is an “institutional accredited investor” within the meaning of Rule 501 of Regulation D under the Securities Act, and is acquiring the Common Stock for investment purposes only and not with a view to any public distribution or wi…