A Clinical Trial of CAP-002 Gene Therapy in Pediatric Patients With Syntaxin-Binding Protein 1 (STXBP1) Encephalopathy

Prior treatment

• History of prior gene therapy;
• Treatment with antisense oligonucleotide therapy within 6 months;
• Known contraindication to immunosuppression or other protocol-defined medications, including but not limited to corticosteroids or PPIs;
• Positive anti-capsid antibody test result.

Other illness

• Presence of a confirmed mutation in a gene other than STXBP1 that is known to contribute to a neurodevelopmental disability or epilepsy;
• Has presence of a significant non-STXBP1-related central nervous impairment/behavioral disturbance that would confound the scientific rigor or interpretation of results of the trial;
• Other illnesses or medications that may affect the interpretation of the study results;

Age

• History of prematurity (defined as gestational age <35 weeks), history of low birth weight (<2.5 kg) and/or intra-uterine growth restriction, significant interventricular hemorrhage, structural brain deficit, or congenital heart disease;

Other

• Clinically significant abnormalities in safety lab tests, vital signs;

• Male or female, ≥18 months to <8 years of age;
• Has diagnosis of developmental encephalopathy due to an STXBP1 mutation with confirmation of a pathogenic or likely pathogenic STXBP1 gene mutation.
• Has a legally authorized representative (LAR) willing and able to complete the informed consent process, willing to comply with trial procedures, and able to travel for repeat visits.
• Is stable on any medication regimens (if being administered to control the signs and symptoms of underlying disease) for at least 6 weeks prior to trial entry and expected to be stable for at least 12 weeks post-CAP-002 administration.