Gene Therapy for Developmental Encephalopathy

Not currently recruiting at 4 trial locations

Overseen By Lori Brozena

Age: < 18

Sex: Any

Trial Phase: Phase 1 & 2

Sponsor: Capsida Biotherapeutics, Inc.

Must not be taking: Antisense oligonucleotides, corticosteroids

Disqualifiers: Gene therapy history, prematurity, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 3

Duration: 2 years

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests the safety and effectiveness of a new gene therapy called CAP-002 for children with STXBP1 Encephalopathy, a rare brain condition. The therapy aims to assist children with this condition, whether they experience seizures or not. Participants will receive a one-time infusion of CAP-002 and must visit the clinic regularly over two years for follow-up tests and evaluations. This study may suit children with a confirmed STXBP1 gene mutation who are stable on their current medications. As a Phase 1/Phase 2 trial, the research focuses on understanding how the treatment works in people and measuring its effectiveness in an initial, smaller group, offering participants the chance to be among the first to benefit from this innovative therapy.

Will I have to stop taking my current medications?

The trial requires that participants be stable on their current medications for at least 6 weeks before starting and remain stable for at least 12 weeks after receiving the gene therapy. This means you should not stop taking your current medications if they are controlling your symptoms.

Is there any evidence suggesting that CAP-002 gene therapy is likely to be safe for humans?

Research findings suggest that CAP-002 gene therapy may be safe. Data from previous studies show that a single dose of CAP-002 might help with seizures, developmental issues, and motor problems. In earlier research, participants generally tolerated the treatment well.

However, one study reported a 3.2% death rate among patients with conditions related to STXBP1, highlighting the need for careful monitoring and consideration of potential risks.

Overall, while CAP-002 shows promise, ongoing trials are crucial to fully understand its safety in children with STXBP1 encephalopathy. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising?

Researchers are excited about CAP-002 for developmental encephalopathy because it uses gene therapy to target the root cause of the condition. Unlike current treatments that mainly focus on managing symptoms, CAP-002 involves delivering a single dose of the STXBP1 gene intravenously to address the underlying genetic defect. This approach has the potential to offer more sustainable and long-lasting benefits, fundamentally changing how we approach treatment for this condition.

What evidence suggests that CAP-002 might be an effective treatment for STXBP1 Encephalopathy?

Research shows that CAP-002 gene therapy has potential in early studies by delivering the STXBP1 gene throughout the brain. This therapy aims to help children with STXBP1 Encephalopathy, a condition that can cause developmental issues and seizures. Studies have shown that CAP-002 can reach up to 70% of brain cells, potentially improving seizure control and developmental progress. In this trial, participants will receive a single infusion of the treatment into the bloodstream, targeting the entire brain. Although research in humans is ongoing, these early results offer hope for those affected by this condition. ^{2 3 6 7 8}

Who Is on the Research Team?

Melanie Brandabur, MD

Principal Investigator

Capsida Biotherapeutics

Are You a Good Fit for This Trial?

This trial is for pediatric patients with STXBP1 Encephalopathy, a developmental brain disorder. Participants must have a confirmed diagnosis and may or may not experience seizures. Specific inclusion and exclusion criteria details are not provided but typically involve health status and other medical conditions.

Inclusion Criteria

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

I have a developmental brain disorder caused by an STXBP1 mutation.

My current medications have been stable for 6 weeks and will remain so for 12 weeks after starting the trial.

Exclusion Criteria

I have a genetic mutation linked to epilepsy or neurodevelopmental issues, not in the STXBP1 gene.

I haven't had antisense oligonucleotide therapy in the last 6 months.

I have had gene therapy before.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Dose Escalation

Participants receive a single intravenous infusion of CAP-002 in a dose-escalation format

Varies

Multiple visits for dose escalation

Treatment

Participants receive a single intravenous infusion of CAP-002 and are monitored for safety and efficacy

2 years

Regular clinic visits for checkups and tests

Follow-up

Participants are monitored for safety and effectiveness after treatment

3 years

Invited to participate in a 3-year safety follow-up study

What Are the Treatments Tested in This Trial?

Interventions

• CAP-002

Trial Overview The study tests the safety and effectiveness of CAP-002 gene therapy in treating children with STXBP1 Encephalopathy. It involves one infusion of the therapy followed by regular clinic visits over two years for monitoring, including seizure tracking by caregivers.

How Is the Trial Designed?

Group I: Dose Level 2 Experimental Treatment 1 Intervention

Participants will receive a single dose of STXBP1, administered IV

Group II: Dose Level 1 Experimental Treatment 1 Intervention

Participants will receive a single dose of STXBP1, administered IV

Who Is Running the Clinical Trial?

Capsida Biotherapeutics, Inc.

Lead Sponsor

Trials

1

Citations

1. clinicaltrials.gov clinicaltrials.gov/study/NCT06983158

A Clinical Trial of CAP-002 Gene Therapy in Pediatric ... The goal of this clinical trial is to learn about the safety of CAP-002 gene therapy in children with Syntaxin-Binding Protein 1 (STXBP1) Encephalopathy.

2. stxbp1disorders.org stxbp1disorders.org/news/capsida-to-present-progress-updates-at-the-asgct-annual-meeting

Capsida to Present Progress Updates on CAP-002 at the ... Capsida Receives FDA IND Clearance for Its First-in-Class, IV-administered Gene Therapy for STXBP1 Developmental and Epileptic Encephalopathy.

3. capsida.com capsida.com/capsida-biotherapeutics-presents-new-preclinical-evidence/

Capsida Biotherapeutics The data show that a single IV infusion of CAP-002 results in brain-wide STXBP1 gene expression and is capable of transducing up to 70% of ...

4. neurologylive.com neurologylive.com/view/fda-clears-ind-study-gene-therapy-cap-002-stxbp1-developmental-epileptic-encephalopathy

FDA Clears IND to Study Gene Therapy CAP-002 in ... FDA approves study to test Capsida's CAP-002 gene therapy for STXBP1-DEE, offering hope for improved seizure control and developmental outcomes in affected ...

5. firstwordpharma.com firstwordpharma.com/story/6061410

Capsida suspends gene therapy trial after first patient dies Efficacy data from the trial is expected in the first quarter of 2026, according to a company presentation last month. STXBP1-DEE is a rare ...

6. capsida.com capsida.com/capsida-presents-new-glp-toxicology-data-supporting-recent-fda-ind-clearance-of-its-first-in-class-iv-administered-gene-therapy-for-stxbp1-developmental-and-epileptic-encephalopathy/

Capsida Presents New GLP Toxicology Data Supporting ... Data show CAP-002 has potential to safely correct seizures, developmental disabilities, and motor abnormalities after single IV infusion.

7. centerwatch.com centerwatch.com/clinical-trials/listings/NCT06983158/a-clinical-trial-of-cap-002-gene-therapy-in-pediatric-patients-with-syntaxin-binding-protein-1-stxbp1-encephalopathy?id=934&slug=dravet-syndrome

A Clinical Trial of CAP-002 Gene Therapy in Pediatric ... The goal of this clinical trial is to learn about the safety of CAP-002 gene therapy in children with Syntaxin-Binding Protein 1 (STXBP1) ...

8. pharmexec.com pharmexec.com/view/capsida-halts-cap-002-gene-therapy-trial-stxbp1-related-disorders-patient-death

Capsida Halts CAP-002 Gene Therapy Trial in STXBP1- ... Results from an October 2024 study published in Neurological Sciences showed a mortality rate of 3.2% for patients with pathogenic STXBP1 ...