OPAL

• Research type

  Research Study

• Full title

  A Phase 2, Double-Blind Study to Evaluate the Pharmacokinetics, Pharmacodynamics, Efficacy, and Safety of Apitegromab in Subjects <2 Years Old with Spinal Muscular Atrophy (SMA)

• IRAS ID

  1012301

• Contact name

  Kelley Capocelli

• Contact email

  kcapocelli@scholarrock.com

• Sponsor organisation

  Scholar Rock, Inc.

• Clinicaltrials.gov Identifier

  NCT07047144

• Research summary

  The purpose of the OPAL study is to learn more about the potential effectiveness, tolerability and safety of an investigational (or study) drug called apitegromab in children less than 2 years of age with Spinal Muscular Atrophy (SMA). Currently, there are approved treatments available to help treat SMA, but there are no approved treatments that specifically focus on treating muscle atrophy (a condition in which a person’s muscles are smaller and weaker than those of their peers) in SMA. Apitegromab is a protein that acts upon a muscle protein called myostatin, which is one of the factors that controls the size of muscles and motor function (how well muscles work). It is being developed as a potential first muscle-targeted therapy for people with SMA.
  The participants of the OPAL study are those who have SMA and have previously taken SMN therapies such as onasemnogene abeparvovec-xioi or are currently taking nusinersen (Spinraza) or risdiplam (Evrysdi). These therapies are approved by the Medicines and Healthcare products Regulatory Agency (MHRA) for the treatment of SMA and are only available via managed access agreements. However, the use of these medications with apitegromab is not an approved combination for the treatment of SMA.
  Participants will be randomized approximately 1:1 to receive apitegromab by intravenous (IV) infusion at 2 doses (either 0.75 mg/kg group or 7.5 mg/kg group) every 4 weeks for 48 weeks. The Sponsor, the participant's caregiver, as well as the Investigator and site personnel, with the exception of the designated unblinded personnel (eg, site Pharmacist), will be blinded to the treatment assignment until the completion of the extension study. Participants who complete the 48-week treatment/assessments will be offered the option to enter an extension study at that time. Participants who choose not to enroll in the extension study will be followed off treatment for a 20-week Safety Follow-up.

• REC name

  London - Hampstead Research Ethics Committee

• REC reference

  25/LO/0843

• Date of REC Opinion

  5 Dec 2025

• REC opinion

  Further Information Favourable Opinion