UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 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): March 1926, 2026

RHYTHM PHARMACEUTICALS, INC.

(Exact name of registrant as specified in its charter)


Delaware	001-38223	46-2159271
(State or other jurisdiction of incorporation)	(Commission File Number)	(IRS Employer Identification Number)

222 Berkeley Street

12th Floor

Boston, MA 02116

(Address of principal executive offices) (Zip Code)

Registrant’s telephone number, including area code: (857) 264-4280

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:

☐ 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, $0.001 par value per share	RYTM	The Nasdaq Stock Market LLC (Nasdaq Global Market)

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. ☐

Item 7.01. Regulation FD Disclosure.

On March 1926, 2026, Rhythm Pharmaceuticals, Inc. (“Rhythm”) issued a press release ~~and~~announcing ~~published~~that athe ~~presentation~~European ~~announcing~~Medicines ~~that~~Agency's ~~the~~(EMA) ~~U.S.~~Committee ~~Food~~for ~~and~~Medicinal ~~Drug~~Products ~~Administration~~for Human Use (~~FDA~~CHMP) has ~~approved~~adopted ana ~~expanded~~positive ~~indication~~opinion recommending to expand the current marketing authorization for IMCIVREE® (setmelanotide) to ~~treat~~include ~~patients~~the ~~living~~treatment ~~with~~of ~~acquired~~obesity ~~hypothalamic~~and ~~obesity~~the ~~(HO),~~control ~~which~~of ishunger ~~summarized~~in ~~under~~adults ~~Item~~and ~~8.01~~children ~~below.~~4 ~~The~~years ~~presentation~~of isage ~~available~~and inabove ~~the~~with ~~“Events~~acquired ~~and~~hypothalamic ~~Presentations”~~obesity ~~portion~~(HO) ofdue ~~the~~to ~~Company’s~~hypothalamic ~~website~~injury ator irimpairment.~~rhythmtx.com.~~ A copy of the press release ~~and~~is ~~presentation are~~ furnished as ~~Exhibits~~Exhibit 99.1 ~~and 99.2, respectively,~~ to this Current Report on Form 8-K.

The information contained in Item 7.01 of this Current Report on Form 8-K (including ~~Exhibits~~Exhibit 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 of 1933, as amended (the “Securities Act”), or the Exchange Act, except as expressly provided by specific reference in such a filing.

Item 8.01. Other Events.

On March 1926, 2026, Rhythm announced that the ~~U.S.~~European ~~Food~~Medicines ~~and~~Agency's ~~Drug Administration~~ (~~FDA~~EMA) ~~has~~Committee ~~approved~~for anMedicinal ~~expanded~~Products ~~indication~~ for ~~IMCIVREE®~~Human Use (~~setmelanotide~~CHMP) tohas ~~treat~~adopted ~~patients~~a ~~living~~positive ~~with~~opinion ~~acquired~~recommending ~~hypothalamic~~to ~~obesity~~expand ~~(HO).~~the ~~With~~current ~~this~~marketing ~~expansion,~~authorization for IMCIVREE® is(setmelanotide) ~~indicated~~ to ~~reduce~~include ~~excess~~the ~~body~~treatment ~~weight~~of obesity and ~~maintain~~the ~~reduction~~control ~~long~~of ~~term~~hunger in adults and ~~pediatric~~children ~~patients aged~~ 4 years of age and ~~older~~above with acquired hypothalamic obesity (HO) due to hypothalamic injury or impairment.

The ~~approval~~CHMP isopinion ~~supported~~will bynow ~~the~~be ~~positive~~reviewed ~~pivotal~~by ~~Phase~~the 3European ~~TRANSCEND~~Commission ~~trial of setmelanotide in 142 patients with acquired HO. The global study met its primary endpoint, with a statistically significant -18.4% placebo-adjusted reduction in body mass index~~ (~~BMI~~EC)~~. For the primary endpoint of mean BMI change from baseline~~, ~~study~~which ~~participants~~has onthe ~~setmelanotide~~authority ~~therapy~~to ~~(n=94)~~grant ~~achieved~~and aexpand ~~-15.8%~~marketing ~~reduction~~authorizations ~~compared~~for ~~with~~medicinal aproducts ~~+2.6% increase among patients on placebo (n=48) at 52 weeks (p<0.0001). Setmelanotide was generally well tolerated~~ in the ~~Phase~~European ~~3 trial~~Union. ~~The~~A ~~most~~final ~~common~~decision ~~treatment-emergent~~is ~~adverse~~anticipated ~~events~~in ~~(affecting~~the ~~>20%~~second quarter of ~~participants) were skin hyperpigmentation, nausea, vomiting and headache~~2026.

Forward-Looking Statements

This Current Report on Form 8-K contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements contained in this Current Report that do not relate to matters of historical fact should be considered forward-looking statements, including without limitation statements regarding the review of the CHMP opinion by the EC and the timing of the final decision. Statements using words such as “expect”, “anticipate”, “believe”, “may”, “will” and similar terms are also forward-looking statements. Such statements are subject to numerous risks and uncertainties, including, but not limited to, our ability to enroll patients in clinical trials, the design and outcome of clinical trials, the impact of competition, the ability to achieve or obtain necessary regulatory approvals, risks associated with data analysis and reporting, unfavorable pricing regulations, third-party reimbursement practices or healthcare reform initiatives, risks associated with the laws and regulations governing our international operations and the costs of any related compliance programs, our ability to successfully commercialize setmelanotide, our liquidity and expenses, our ability to retain our key employees and consultants, and to attract, retain and motivate qualified personnel, and general economic conditions, and the other important factors, including those discussed under the caption “Risk Factors” in Rhythm’s Annual Report on Form 10-K for the year ended December 31, 2025 and our other filings with the Securities and Exchange Commission. Except as required by law, we undertake no obligations to make any revisions to the forward-looking statements contained in this Current Report or to update them to reflect events or circumstances occurring after the date of this Current Report, whether as a result of new information, future developments or otherwise

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits

The following ~~Exhibits~~Exhibit 99.1 ~~and 99.2~~ shall be deemed to be furnished and not filed.

ExhibitNo.						Description
99.1						Press release dated March 1926, 2026
99.2						Presentation dated March 19, 2026
104						Cover Page Interactive Data File (embedded within the inline XBRL document)

SIGNATURES

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.

	RHYTHM PHARMACEUTICALS, INC.
Date: March 20, 2026	By:	/s/ Hunter Smith
Date: March 26, 2026	By:	/s/ Hunter Smith
		Hunter Smith
		Chief Financial Officer

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