NTLA halts nex-z Phase 3 dosing after Grade 4 liver event

Rhea-AI Filing Summary

Intellia Therapeutics temporarily paused dosing and screening in its Phase 3 MAGNITUDE (ATTR-CM) and MAGNITUDE-2 (ATTRv-PN) trials of nexiguran ziclumeran (nex-z) after a safety event met protocol-defined pausing criteria.

The action follows an October 24 report of Grade 4 liver transaminases and increased total bilirubin in a patient dosed on September 30 in MAGNITUDE. More than 650 patients with ATTR-CM are enrolled in MAGNITUDE and 47 patients with ATTR-PN are enrolled in MAGNITUDE-2; over 450 patients are estimated to have been dosed with nex-z. The company furnished a press release as Exhibit 99.1 and included standard forward-looking statements regarding the ability to resume and complete these studies.

Positive

• None.

Negative

• Temporary pause of Phase 3 MAGNITUDE and MAGNITUDE-2 after a Grade 4 liver transaminase and bilirubin event in a MAGNITUDE patient, meeting protocol-defined pausing criteria.

Insights

Biotech clinical development analyst

Phase 3 programs paused after a serious liver event; material clinical risk.

Intellia paused dosing and screening in the Phase 3 MAGNITUDE and MAGNITUDE-2 trials for nex-z after a MAGNITUDE patient experienced Grade 4 liver transaminases with elevated bilirubin, triggering protocol-defined pausing criteria. Such pauses are designed to assess causality and safety signals in a controlled manner.

The trials enroll adults with ATTR-CM and ATTRv-PN. The company reports more than 650 enrolled in MAGNITUDE and 47 in MAGNITUDE-2, with over 450 estimated to have received nex-z. The scale underscores the importance of a careful safety review before resuming.

Next steps hinge on safety evaluations and interactions described generally in forward-looking language. Any resumption or modifications would come through subsequent disclosures; the timing is not specified in the excerpt.

false 0001652130 0001652130 2025-10-27 2025-10-27

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): October 27, 2025

INTELLIA THERAPEUTICS, INC.

(Exact name of registrant as specified in its charter)

Delaware		001-37766		36-4785571
(State or other jurisdiction of incorporation)		(Commission File Number)		(IRS Employer Identification No.)

40 Erie Street, Suite 130
Cambridge, Massachusetts		02139
(Address of principal executive offices)		(Zip Code)

Registrant’s telephone number, including area code: (857) 285-6200

Not Applicable

(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 (Par Value $0.0001)		NTLA		The 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 October 27, 2025, Intellia Therapeutics, Inc. (the “Company or “Intellia”) issued a press release titled “Intellia Therapeutics Provides Update on MAGNITUDE Clinical Trials of Nexiguran Ziclumeran (nex-z).” A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated into this Item 7.01 by reference.

The information in this Item 7.01, 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, 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 a filing.

Item 8.01. Other Events.

On October 27, 2025, the Company announced it has temporarily paused dosing and screening in the MAGNITUDE and MAGNITUDE-2 Phase 3 clinical trials for nexiguran ziclumeran (“nex-z”).

The MAGNITUDE trial is a randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of nex-z in adults with transthyretin (“ATTR”) amyloidosis with cardiomyopathy (“ATTR-CM”). The MAGNITUDE-2 trial is a randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of nex-z in adults with hereditary ATTR amyloidosis with polyneuropathy (“ATTRv-PN”).

This action follows a report on October 24, 2025 of Grade 4 liver transaminases and increased total bilirubin in a patient who was dosed with nex-z in the MAGNITUDE trial on September 30, 2025, meeting the trial’s protocol-defined pausing criteria.

As of today, more than 650 patients with ATTR-CM are enrolled in MAGNITUDE, and 47 patients with ATTR-PN are enrolled in MAGNITUDE-2. Over 450 of these patients are estimated to have been dosed with nex-z.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit  No.		Description
99.1		Press Release dated October 27, 2025 titled “Intellia Therapeutics Provides Update on MAGNITUDE Clinical Trials of Nexiguran Ziclumeran (nex-z)”
104		Cover Page Interactive Data File (embedded within the Inline XBRL document)

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, as amended. The words “may,” “will,” “could,” “would,” “should,” “expect,” “plan,” “anticipate,” “intend,” “believe,” “estimate,” “predict,” “project,” “potential,” “continue,” “target” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. These forward-looking statements include, but are not limited to, express or implied statements regarding Intellia’s beliefs and expectations regarding: the safety, tolerability, efficacy, success and advancement of its clinical programs for “nex-z” (also known as NTLA-2001), including the ability to resume and successfully complete its MAGNITUDE and MAGNITUDE-2 trials for nex-z. Any forward-looking statements in this current report on Form 8-K are based on management’s current expectations and beliefs of future events and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by such forward-looking statements. These risks and uncertainties include, but are not

limited to: uncertainties related to Intellia’s ability to resume the MAGNITUDE and MAGNITUDE-2 trials, the implications of this event on the safety and efficacy of nex-z and further development of nex-z; regulatory agencies’ evaluation of regulatory filings and other information related to our product candidates, including nex-z; uncertainties related to the authorization, initiation and conduct of studies and other development requirements for our product candidates, including uncertainties related to regulatory approvals to conduct clinical trials; the risk that any one or more of Intellia’s product candidates, including nex-z, will not be successfully developed and commercialized; risks related to Intellia’s ability to protect and maintain its intellectual property position; risks related to valid third party intellectual property; risks related to Intellia’s relationship with third parties, including its licensors and licensees; risks related to the ability of its licensors to protect and maintain their intellectual property position; the risk that the results of preclinical studies or clinical studies will not be predictive of future results in connection with future studies for the same product candidate or Intellia’s other product candidates; and risks related to Intellia’s reliance on collaborations, including that its collaboration with Regeneron Pharmaceuticals, Inc. will not continue or will not be successful. For a discussion of these and other risks and uncertainties, and other important factors, any of which could cause Intellia’s actual results to differ from those contained in the forward-looking statements, see the section entitled “Risk Factors” in Intellia’s most recent annual report on Form 10-K and quarterly report on Form 10-Q, as well as discussions of potential risks, uncertainties, and other important factors in Intellia’s other filings with the Securities and Exchange Commission. All information in this current report on Form 8-K is as of the date of the report, and Intellia undertakes no duty to update this information unless required by law.

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.

				Intellia Therapeutics, Inc.
						(Registrant)
Date: October 27, 2025				By:		/s/ John M. Leonard
						Name: John M. Leonard
						Title: Chief Executive Officer and President

FAQ

What did NTLA announce about its MAGNITUDE trials?

The company temporarily paused dosing and screening in the Phase 3 MAGNITUDE (ATTR-CM) and MAGNITUDE-2 (ATTRv-PN) trials of nexiguran ziclumeran (nex-z).

Why were Intellia's Phase 3 trials paused?

A MAGNITUDE patient had Grade 4 liver transaminases with increased total bilirubin reported on October 24, meeting protocol-defined pausing criteria.

How many patients are enrolled in NTLA’s Phase 3 programs?

More than 650 patients with ATTR-CM are enrolled in MAGNITUDE and 47 patients with ATTR-PN are enrolled in MAGNITUDE-2.

How many patients have received nex-z in these studies?

Over 450 patients are estimated to have been dosed with nexiguran ziclumeran (nex-z).

What additional information did Intellia provide with this update?

A press release titled “Intellia Therapeutics Provides Update on MAGNITUDE Clinical Trials of Nexiguran Ziclumeran (nex-z)” was furnished as Exhibit 99.1.

Does the filing discuss when the trials may resume?

It includes forward-looking statements about the ability to resume and complete the trials but does not specify timing in the provided excerpt.