Sarepta Therapeutics (SRPT) Study result summary

Study Overview and Rationale

• Preliminary phase I/II data for SRP-1001 (FSHD1) and SRP-1003 (DM1) show robust, dose-dependent muscle delivery and strong gene knockdown, targeting life-limiting muscular dystrophies with no current disease-modifying therapies.

• Both programs utilize the TRiM siRNA platform with αvβ6 integrin-targeting ligands for enhanced muscle delivery, outperforming transferrin receptor-based approaches and reducing toxicity.

• Preclinical and early clinical data show dose-dependent increases in muscle and plasma concentrations without evidence of receptor saturation.

• The TRiM platform demonstrates robust gene knockdown, favorable safety margins in animal models, and is designed for chronic administration in neuromuscular and CNS diseases.

• The siRNA platform pipeline includes SRP-1001 (FSHD), SRP-1002 (IPF), SRP-1003 (DM1), SRP-1004 (SCA2), and SRP-1005 (HD), with preclinical programs for SCA1, SCA3, and other disorders.

Study Design and Objectives

• Phase 1/2 randomized, placebo-controlled trials evaluated SRP-1001 in FSHD1 (ages 16–70) and SRP-1003 in DM1 (ages 18–65), with single and multiple ascending dose cohorts.

• Primary endpoints focused on safety and tolerability; secondary and exploratory endpoints included pharmacokinetics, muscle siRNA concentration, target engagement, and biomarker changes.

• Both studies are developed under an exclusive license with Arrowhead Pharmaceuticals.

Mechanism and Delivery Platform

• TRiM platform uses integrin αvβ6-targeting ligands for enhanced muscle delivery, with siRNA chemistry and linker modifications optimizing potency, stability, and dosing intervals.

• siRNA-mediated mRNA degradation enables specific knockdown of disease-driving genes (DUX4 in FSHD1, DMPK in DM1).