Sarepta Therapeutics Announces Submission of Clinical Trial Application for SRP-1005, its Investigational Treatment for Huntington’s Disease

Key Terms

clinical trial application (CTA) regulatory

A clinical trial application (CTA) is the formal request a company files with health regulators asking permission to begin testing a new drug or medical device in people. It matters to investors because approval is a key development milestone—like getting a building permit to start construction—signaling reduced regulatory risk, unlocking the next phase of data generation and timelines for potential commercial value, while rejection or delay can push back prospects and increase costs.

small interfering RNA (siRNA) medical

Small interfering RNA (siRNA) are short, lab-designed molecules that act like a targeted mute button for specific genes, binding to and prompting the cell to destroy matching genetic messages so a particular protein is not produced. For investors, siRNA represents a therapeutic technology platform: its ability to precisely switch off disease-causing genes can create new drug candidates, shape clinical and regulatory risk, and influence long-term commercial potential in biotechnology and pharma.

TfR1 (transferrin receptor protein 1) medical

A cell-surface protein that acts like a doorway for iron-carrying molecules, allowing cells to take up the iron they need to function and grow. Investors watch tfr1 because changes in its levels or function can indicate disease, serve as a target for therapies or diagnostic tests, and affect the safety and effectiveness of drugs that rely on or alter iron handling—making it relevant to valuations and clinical development risks.

fragment antigen binding (fAb) medical

Fragment antigen binding (Fab) is the part of an antibody that directly recognizes and sticks to a specific target, like the grippy piece of Velcro that latches onto a matching strip. Investors care because many drugs and diagnostic tests use Fab fragments for targeted action; their size and binding properties can change a therapy’s effectiveness, side-effect profile, dosing and manufacturing complexity, and therefore affect approval chances, costs and patent value.

central nervous system medical

The central nervous system (CNS) is the body's main control center, made up of the brain and spinal cord, that processes information and directs movement, sensation and basic functions like breathing. For investors, CNS-related products and research matter because they face long development times, strict safety testing and regulatory hurdles; success or failure can dramatically affect a company’s costs, timelines and potential market value.

blood brain barrier medical

A selective biological barrier formed by tightly joined cells around the brain’s blood vessels that controls which chemicals, medicines, and cells can pass from the bloodstream into the brain, acting like a security checkpoint or fine sieve. It matters to investors because a drug’s ability to cross or be excluded by this barrier can make or break development, affecting clinical success, regulatory approval, timelines, and commercial potential in neurological and psychiatric markets.

Phase 1 medical

Phase 1 is the first stage of testing a new drug or medical treatment in people, focused primarily on safety, how the body handles the product, and finding a tolerated dose. Think of it as a short, tightly controlled experiment with a small group to check for dangerous side effects before wider testing; for investors it is an early milestone that reduces some uncertainty but still carries high risk and potential for both big value changes and setbacks.

– The first-in-human clinical study of SRP-1005, known as INSIGHTT, is expected to begin in the second quarter of 2026

CAMBRIDGE, Mass.--(BUSINESS WIRE)-- Sarepta Therapeutics, Inc. (NASDAQ:SRPT), the leader in precision genetic medicine for rare diseases, today announced the submission of its clinical trial application (CTA) for Study SRP-1005-101, also known as INSIGHTT, to Medsafe, the New Zealand Medicines and Medical Devices Safety Authority. Pending approval, Sarepta expects to initiate this first-in-human clinical trial of SRP-1005 (formerly ARO-HTT) in the second quarter of 2026. SRP-1005 is an investigational small interfering RNA (siRNA) therapeutic for the treatment of Huntington’s Disease.

“Huntington’s disease is a devastating, progressive condition with extremely limited therapeutic options and no approved treatments to slow or halt its course. Families carry the burden across generations, and the need for new approaches is urgent,” said Louise Rodino-Klapac, Ph.D., president of research & development and technical operations, Sarepta. “SRP-1005, a subcutaneously dosed siRNA therapy intended to target the deep brain and knock down the protein that causes Huntington’s disease, represents a novel and potentially paradigm changing approach to the treatment of this devastating disease.”

INSIGHTT is a Phase 1, multi-center, dose escalation study that will evaluate the safety and tolerability of subcutaneous dosing of SRP-1005 in approximately 24 participants. SRP-1005 leverages an advanced TfR1 (transferrin receptor protein 1) approach that uses monovalent fragment antigen binding (fAb) designed for efficient delivery to the central nervous system. Subcutaneous delivery aims to allow the therapy to stay below transferrin saturation and achieve constant and robust penetration across the blood brain barrier. Preclinical data with SRP-1005 have demonstrated the potential for significant protein knockdown in key deep brain regions, including the putamen and caudate, as well as the temporal and frontal cortexes.

About Huntington’s Disease

Huntington’s Disease (HD) is a rare and ultimately fatal inherited neurodegenerative disorder which is passed down from generation to generation within affected families. HD is caused by a mutation in the gene for a protein called huntingtin, or HTT, which leads to progressive deterioration of nerve cells in the brain, affecting cognition, movement, and behavior. In the U.S. about 40,000 people are living with symptomatic HD, and an additional 200,000 individuals carry the genetic mutation and are at risk of developing symptoms. Symptoms typically appear between ages 30 and 50 and worsen over time, with every child of an affected parent having a 50% chance of inheriting the condition. There is currently no known cure or approved disease-modifying treatments that address the underlying cause.

About Sarepta’s siRNA Platform

Sarepta’s next-generation siRNA platform is focused on chronically administered therapies for neurodegenerative and pulmonary diseases and includes investigational treatments for:

• Facioscapulohumeral muscular dystrophy (FSHD)
• Myotonic dystrophy type 1 (DM1)
• Spinocerebellar ataxia type 2 (SCA2)
• Idiopathic Pulmonary Fibrosis (IPF)
• Huntington’s disease (HD)

Sarepta is also pursuing preclinical programs for Spinocerebellar ataxia type 1 (SCA1) and Spinocerebellar ataxia type 3 (SCA3) and has an exclusive collaboration with Arrowhead Pharmaceuticals to develop therapies for skeletal muscle diseases, with plans to pursue up to six discovery targets in muscle or central nervous system disorders.

About Sarepta Therapeutics

Sarepta is on an urgent mission: engineer precision genetic medicine for rare diseases that devastate lives and cut futures short. We hold leadership positions in Duchenne muscular dystrophy (Duchenne) and are building a robust portfolio of programs across muscle, central nervous system, and cardiac diseases. For more information, please visit www.sarepta.com or follow us on LinkedIn, X, Instagram and Facebook.

Internet Posting of Information

We routinely post information that may be important to investors in the 'For Investors' section of our website at www.sarepta.com. We encourage investors and potential investors to consult our website regularly for important information about us.

Forward-Looking Statements

This press release contains forward-looking statements. Any statements contained in this press release that are not statements of historical fact may be deemed to be forward-looking statements. Words such as "believes," "anticipates," "plans," "expects," "will," "intends," "potential," "possible" and similar expressions are intended to identify forward-looking statements. These forward-looking statements include statements related to our priorities, technologies and research and development programs; the potential benefits of SRP-1005; and expected plans and milestones, including our expectation to initiate SRP-1005 in the second quarter of 2026.

These forward-looking statements involve risks and uncertainties, many of which are beyond Sarepta’s control. Known risk factors include, among others: success in preclinical and clinical trials, especially if based on a small patient sample, does not ensure that later clinical trials will be successful, and the results of future research may not be consistent with past positive results or may fail to meet regulatory approval requirements for the safety and efficacy of product candidates; certain programs may never advance in the clinic or may be discontinued for a number of reasons, including regulators imposing a clinical hold and us suspending or terminating clinical research or trials; if the actual number of patients suffering from the diseases we aim to treat is smaller than estimated, our revenue and ability to achieve profitability may be adversely affected; we may not be able to execute on our business plans, including meeting expected or planned regulatory milestones and timelines, clinical development plans, and bringing products to markets for various reasons including possible limitations of financial and other resources, manufacturing limitations that may not be anticipated or resolved for in a timely manner, and regulatory, court or agency decisions, such as decisions by the United States Patent and Trademark Office with respect to patents that cover our product candidates; and those risks identified under the heading “Risk Factors” in Sarepta’s most recent Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission (SEC) as well as other SEC filings made by the Company which you are encouraged to review.

Any of the foregoing risks could materially and adversely affect the Company’s business, results of operations and the trading price of Sarepta’s common stock. For a detailed description of risks and uncertainties Sarepta faces, you are encouraged to review the SEC filings made by Sarepta. We caution investors not to place considerable reliance on the forward-looking statements contained in this press release. Sarepta does not undertake any obligation to publicly update its forward-looking statements based on events or circumstances after the date hereof, except as required by law.

View source version on businesswire.com: https://www.businesswire.com/news/home/20260107174240/en/

Investor Contacts:

Ian Estepan

617-274-4052

iestepan@sarepta.com

Ryan Wong

617-800-4112

rwong@sarepta.com

Media Contacts:

Tracy Sorrentino

617-301-8566

tsorrentino@sarepta.com

Source: Sarepta Therapeutics, Inc.