Intellia Announces First Clinical Evidence from Ongoing Phase 1 Study that nexiguran ziclumeran (nex-z), an In Vivo CRISPR/Cas9-Based Gene Editing Therapy, May Favorably Impact Disease Progression in Transthyretin (ATTR)

Intellia Announces First Clinical Evidence from Ongoing Phase 1 Study that nexiguran ziclumeran (nex-z),

an In Vivo CRISPR/Cas9-Based Gene Editing Therapy, May Favorably Impact Disease Progression in Transthyretin (ATTR) Amyloidosis

CAMBRIDGE, Mass., Nov. 16, 2024 (GLOBE NEWSWIRE) Intellia Therapeutics, Inc. (NASDAQ:NTLA), a leading clinical-stage gene

editing company focused on revolutionizing medicine with CRISPR-based therapies, today announced positive new clinical data from the ongoing Phase 1 trial of nexiguran ziclumeran (nex-z, also known as NTLA-2001) in patients with transthyretin (ATTR)

amyloidosis. Nex-z is an investigational in vivo CRISPR-based gene editing therapy in development as a one-time treatment for ATTR amyloidosis. Development and commercialization of nex-z is led by Intellia as part of a multi-target

collaboration with Regeneron.

The Phase 1 trial is an open-label, two-part study evaluating the safety and activity of nex-z in patients with either ATTR

amyloidosis with cardiomyopathy (ATTR-CM) or hereditary ATTR amyloidosis with polyneuropathy (ATTRv-PN). New results from the Phase 1 study were as of the data cut-off date of August 21, 2024. The data from the ATTR-CM arm of the Phase 1 study were

presented in a late-breaking oral presentation at the 2024 American Heart Association (AHA) Scientific Sessions in Chicago, Illinois, and published online in the New England Journal of Medicine.

The Phase 1 data presented today offer compelling evidence that deep and persistently low levels of

TTR reduction achieved with nex-z, an investigational in vivo CRISPR-based gene editing therapy, may favorably impact disease progression for people living with ATTR amyloidosis, said Intellia President and Chief Executive Officer John

Leonard, M.D. The stability or improvement observed after a single dose of nex-z in multiple markers of cardiac disease progression is remarkable, especially considering the high proportion of patients with cardiomyopathy who had advanced

heart failure. We observed similarly positive and consistent trends, indicative of a disease-modifying effect, in patients with hereditary ATTR amyloidosis with polyneuropathy. These results from the ongoing Phase 1 study increase our belief in the

likelihood of success of our active Phase 3 studies based on our hypothesis that greater TTR reduction may lead to greater clinical benefit.

ATTRv-PN Arm Results

*n=14, n=19, n=20, N/A: Data for this time point is not yet available for the full cohort and will

be reported in the future.

Intellia Therapeutics Investor Webcast Information

Intellia will host a live webcast, today, November 16, 2024, at 11:00 a.m. CT / 12:00 p.m. ET to discuss the nex-z Phase 1 data. Joining the Intellia

management team will be Marianna Fontana, M.D., Ph.D., Professor of Cardiology and Honorary Consultant Cardiologist, University College London Centre for Amyloidosis, London, UK.

To join the webcast, please visit this link, or the Events and Presentations page of the Investors & Media section of the company s

website at www.intelliatx.com. A replay of the webcast will be available on Intellia s website for at least 30 days following the call.

About the MAGNITUDE Study

The pivotal Phase 3 MAGNITUDE

clinical trial is a randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of nex-z in approximately 765 patients with transthyretin amyloidosis with cardiomyopathy (ATTR-CM). The primary endpoint of the study is a

composite endpoint of cardiovascular (CV)-related mortality and CV-related events. Adult patients with hereditary or wild type ATTR-CM will be randomized 2:1 to receive a single 55 mg infusion of nex-z or placebo. For more information on MAGNITUDE

(NCT06128629), please visit clinicaltrials.gov.

About the MAGNITUDE-2 Study

MAGNITUDE-2 is a randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of nex-z in 50 adults with ATTRv-PN. Patients will be

randomized 1:1 to receive a single 55 mg infusion of nex-z or placebo. Patients randomized to the placebo arm will be eligible for optional crossover to receive nex-z. The primary endpoints are the change from baseline in modified Neuropathy

Impairment Score +7 (mNIS+7) at month 18 and serum TTR at day 29. For more information on MAGNITUDE-2 (NCT06672237), please visit clinicaltrials.gov.

About nexiguran ziclumeran (nex-z, also known as NTLA-2001)

Based on Nobel Prize-winning CRISPR/Cas9 gene editing technology, nex-z has the potential to become the first one-time treatment for transthyretin (ATTR)

amyloidosis. Nex-z is designed to inactivate the TTR gene that encodes for the transthyretin (TTR) protein. Interim Phase 1 clinical data showed the administration of nex -z led to consistent, deep and long-lasting TTR reduction. Intellia

leads development and commercialization of nex-z as part of a multi-target discovery, development and commercialization collaboration with Regeneron.

About Transthyretin (ATTR) Amyloidosis

amyloidosis, or ATTR amyloidosis, is a rare, progressive and fatal disease. Hereditary ATTR (ATTRv) amyloidosis occurs when a person is born with mutations in the TTR gene, which causes the liver to produce structurally abnormal transthyretin (TTR)

protein with a propensity to misfold. These damaged proteins build up as amyloid in the body, causing serious complications in multiple tissues, including the heart, nerves and digestive system. ATTRv amyloidosis predominantly manifests as

polyneuropathy (ATTRv-PN), which can lead to nerve damage, or cardiomyopathy (ATTRv-CM), which can lead to heart failure. Some individuals without the genetic mutation produce non-mutated, or wild-type TTR proteins that become unstable over time,

misfolding and aggregating in disease-causing amyloid deposits. This condition, called wild-type ATTR (ATTRwt) amyloidosis, primarily affects the heart. There are an estimated 50,000 people worldwide living with ATTRv amyloidosis and between 200,000

and 500,000 people with ATTRwt amyloidosis. There is no known cure for ATTR amyloidosis and currently available medications are limited to slowing accumulation of misfolded TTR protein.

About Intellia Therapeutics

Intellia Therapeutics, Inc.

(NASDAQ:NTLA) is a leading clinical-stage gene editing company focused on revolutionizing medicine with CRISPR-based therapies. The company s in vivo programs use CRISPR to enable precise editing of disease-causing genes directly inside

the human body. Intellia s ex vivo programs use CRISPR to engineer human cells outside the body for the treatment of cancer and autoimmune diseases. Intellia s deep scientific, technical and clinical development experience, along

with its people, is helping set the standard for a new class of medicine. To harness the full potential of gene editing, Intellia continues to expand the capabilities of its CRISPR-based platform with novel editing and delivery technologies. Learn

more at intelliatx.com and follow us @intelliatx.

Forward-Looking Statements

This press release contains forward-looking statements of Intellia Therapeutics, Inc. ( Intellia or the Company ) within the

meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements include, but are not limited to, express or implied statements regarding Intellia s beliefs and expectations regarding: the safety, efficacy,

success and advancement of its clinical programs for nexiguran ziclumeran or nex-z (f/k/a NTLA-2001), for transthyretin ( ATTR ) amyloidosis, including the ability to successfully complete our global Phase 3 MAGNITUDE study for

ATTR amyloidosis with cardiomyopathy ( ATTR-CM ), to initiate and complete our global Phase 3 MAGNITUDE-2 study for hereditary ATTR amyloidosis with polyneuropathy ( ATTRv-PN ) pursuant to our clinical trial applications and

investigational new drug submissions; its belief in the success of its MAGNITUDE and MAGNITUDE-2 studies, and its belief that greater TTR reduction may lead to greater clinical benefit.

Any forward-looking statements in this press release 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: 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; uncertainties related to 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,

including our ability to initiate or enroll the Phase 3 MAGNITUDE study for ATTR-CM or Phase 3 MAGNITUDE-2 study for ATTRv-PN; the risk that any one or more of Intellia s product candidates, including nex-z, will not be successfully developed

and commercialized; 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 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 form 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 press release is as of the date of the release, and

Intellia undertakes no duty to update this information unless required by law.

Senior Director, Investor Relations and Corporate Communications

Ten Bridge Communications