Sarepta Therapeutics has announced that the FDA has lifted the clinical hold on SRP-5051 (vesleteplirsen) following a serious adverse event of hypomagnesemia (low magnesium). SRP-5051 is Sarepta’s next-generation peptide-conjugated phosphorodiamidate morpholino oligomer (PPMO) to treat patients with Duchenne muscular dystrophy who are amenable to exon 51 skipping.

After discussions with FDA and as part of the lift, Sarepta will adjust the global trial protocol to include expanded monitoring of urine biomarkers. Sarepta states that the company will implement the changes in the protocol to resume dosing in the U.S. as quickly as possible.

Read the announcement from Sarepta

CAMBRIDGE, Mass., Sept. 06, 2022 (GLOBE NEWSWIRE) — Sarepta Therapeutics, Inc. (NASDAQ:SRPT), the leader in precision genetic medicine for rare diseases, today announced that the U.S. Food and Drug Administration (FDA) has removed the clinical hold on SRP-5051 (vesleteplirsen), the Company’s investigational, next-generation peptide-conjugated phosphorodiamidate morpholino oligomer (PPMO) to treat patients with Duchenne muscular dystrophy who are amenable to exon 51 skipping. After discussions with FDA and as part of the lift, Sarepta will adjust the global trial protocol to include expanded monitoring of urine biomarkers. ​

The hold in Part B of Study 5051-201, also known as MOMENTUM, followed a serious adverse event of hypomagnesemia. Information was provided by the Company to FDA to assess the adequacy of the risk mitigation and safety monitoring plan.

“We would like to thank FDA for working closely with us to expeditiously resolve this clinical hold. We will implement the changes in the protocol to resume dosing in the U.S. as quickly as possible,” said Louise Rodino-Klapac, Ph.D., executive vice president and chief scientific officer, Sarepta Therapeutics. “Our monitoring plan is designed to mitigate the risks of hypomagnesemia. MOMENTUM has continued enrolling participants outside the U.S., and we remain on track to complete enrollment by the end of 2022. Sarepta is committed to the SRP-5051 program and excited about the PPMO platform as a next-generation exon-skipping approach for the treatment of Duchenne.”

About SRP-5051 (vesleteplirsen)
SRP-5051 is an investigational agent using Sarepta’s PPMO chemistry and exon-skipping technology to skip exon 51 of the dystrophin gene. SRP-5051 is designed to bind to exon 51 of dystrophin pre-mRNA, resulting in exclusion of this exon during mRNA processing in patients with genetic mutations that are amenable to exon 51 skipping. Exon skipping is intended to allow for production of an internally shortened, functional dystrophin protein. PPMO is Sarepta’s next-generation chemistry platform designed around a proprietary cell-penetrating peptide conjugated to the PMO backbone, with the goal of increasing tissue penetration, increasing exon skipping, and significantly increasing dystrophin production. Around 13% of DMD patients have mutations that make them amenable to skipping exon 51. If successful, the PPMO offers the potential for improved efficacy and less frequent dosing for patients.

About MOMENTUM (Study SRP-5051-201)
MOMENTUM is a Phase 2, multi-arm, ascending dose trial of SRP-5051, infused monthly and will assess dystrophin protein levels in skeletal muscle tissue following SRP-5051 treatment. The trial will enroll up to 60 participants, both ambulant and non-ambulant, between the ages of 7 to 21 at sites in the U.S., Canada, and the European Union. The trial will also assess safety and tolerability.

In 2021, the Company announced results from Part A of MOMENTUM showing that after 12 weeks, 30 mg/kg of SRP-5051 dosed monthly resulted in 18 times the exon skipping and eight times the dystrophin production as eteplirsen, dosed weekly for 24 weeks. Reversible hypomagnesemia was identified in patients taking SRP-5051. The protocol for Part B of MOMENTUM includes magnesium supplementation and monitoring of magnesium levels.

More information can be found on www.clinicaltrials.gov.