OPAL trial: apitegromab being studied in children under two with SMA
OPAL trial: apitegromab being studied in children under two with SMA
Page updated: 6th October 2026
A clinical trial is recruiting young children with spinal muscular atrophy (SMA) to investigate apitegromab in children under two years old.
The OPAL study is a Phase 2 clinical trial sponsored by Scholar Rock. It plans to include around 52 children with 5q SMA across several countries, including the UK.
What is the trial looking at?
Apitegromab is designed to work differently from existing SMN-targeted SMA treatments. The OPAL trial is looking at apitegromab alongside an existing SMA treatment.
Researchers want to learn more about how apitegromab behaves in the body in very young children, its safety and tolerability, and whether it may have an effect on motor function.
Children taking part receive apitegromab by intravenous (IV) infusion every four weeks during the treatment period. The study includes children who have received an approved SMN1-targeted treatment, such as gene therapy, or who continue to receive an SMN2-targeted treatment such as nusinersen (Spinraza) or risdiplam (Evrysdi).
Who may be able to take part?
The study is for children who are under two years old when consent is given, have a confirmed diagnosis of 5q SMA and meet a number of other eligibility requirements.
One of the key requirements is that the child has delayed motor milestones attributed to SMA or a CHOP-INTEND motor function score below a specified level. There are additional inclusion and exclusion criteria, and the study team will determine whether an individual child is eligible to participate.
Is the study recruiting in the UK?
Yes. The current trial is recruiting in the UK. Recruitment status can change, so families interested in the study should contact their specialist team or visit the clinicaltrial.gov website to find out more.
What happens next?
The study is expected to assess participants for approximately a year, with motor function outcomes assessed over 48 weeks. The study’s estimated primary completion date is November 2028, with overall completion expected in March 2029.
It is important to remember that this is a clinical trial. Its purpose is to gather evidence about apitegromab in this younger age group, including its safety and whether it has an effect. Participation does not guarantee that an individual child will benefit from the treatment.
Families who are interested in finding out more should discuss the trial with their child’s SMA clinical team and review the full eligibility criteria.