The purpose of this study is to evaluate the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics of SRP-1001 in participants with facioscapulohumeral muscular dystrophy Type 1 (FSHD1). In Part 1 of the study, participants will receive one dose of SRP-1001 or placebo. In Part 2 of the study, participants will receive 4 doses of SRP-1001 or placebo. Participants who complete Part 1 will have the option to re-screen and re-randomize into Part 2. All participants will undergo pre- and post-dose magnetic imaging resonance (MRI)-guided muscle biopsies (a total of 2 biopsies). Participants who complete Part 1 and enroll in Part 2 will be required to undergo an additional screening biopsy. Participants completing Part 1 or Part 2 may have the option to continue to receive drug in an open-label extension study or may be eligible to participate in later-stage clinical studies.
Phase 1 trials primarily test safety and dosing in a small number of participants (typically 20–100). Results do not yet speak to efficacy. FDA approval is typically many years away from this stage.
Phase 2 trials begin testing efficacy in a larger patient group (100–300). This is often where biotech binary events occur — positive Phase 2 data can significantly advance a company's pipeline narrative, while failures can be terminal for a program.
Current status: Enrolling by invitation.
Arrowhead Pharmaceuticals (ARWR) is the sponsoring company for this trial. BiotechSign currently grades this company C (53/100) based on composite catalyst signals across its full pipeline. This trial is one data point in that overall catalyst picture.