JAG201 Gene Therapy Study in Children & Adults With SHANK3 Haploinsufficiency

September 2, 2026 updated by: Jaguar Gene Therapy, LLC

A Phase 1/2, Multicenter, Open-Label, Dose-Escalation, Safety, Tolerability, and Clinical Activity Study of a Single Dose of JAG201 Gene Therapy Delivered Via Intracerebroventricular Administration in Participants With SHANK3 Haploinsufficiency

This is a Phase 1/2, first in human, open-label, dose-escalation study to evaluate the safety, tolerability, and clinical activity of a single dose of JAG201 administered via intracerebroventricular (ICV) injection in pediatric and adult participants with SHANK3 haploinsufficiency resulting from SHANK3 loss of function mutations and chromosomal deletions encompassing the SHANK3 gene. Clinical data will be evaluated for safety, tolerability, and preliminary clinical activity of JAG201 in pediatric and adult participants with SHANK3 haploinsufficiency. The pediatric cohorts will start enrolling first and the enrollment for adult cohorts may be initiated at a later timepoint in the study.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

A target of 6 pediatric participants aged 2 to 9 years will be treated in Cohorts 1 and 2. In total, all participants will be followed for safety and tolerability for at least 5 years after the date of treatment with JAG201. The study will include 5 periods: Pre-Screening, Screening, Gene Therapy Administration and Perioperative Management, Initial Follow-Up, and Long-Term Follow-Up. Study participants will be evaluated for treatment eligibility during the Pre-Screening and Screening Periods. The Pre-Screening/Screening Period may be up to 90 days before treatment with JAG201 (Day 1). On Day 1, treatment-eligible participants will receive a one-time ICV injection of JAG201. Participant safety will be monitored closely after JAG201 administration in a hospital setting. During the Initial Follow-Up Period, up to Year 2, participants will return at regularly scheduled intervals for safety and clinical activity assessments. Participants will continue the study in the Long-Term Follow-Up Period through Year 5.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
6

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • Illinois
      • Chicago, Illinois, United States, 60612
        • Recruiting
        • Rush University
        • Principal Investigator:
          • Elizabeth B Kravis, MD, PhD
        • Contact:
    • Massachusetts
      • Boston, Massachusetts, United States, 02115
        • Recruiting
        • Boston Children's Hospital
        • Contact:
        • Principal Investigator:
          • Siddharth Srivastava, MD
    • New York
      • New York, New York, United States, 10029
        • Recruiting
        • Seaver Autism Center at Mount Sinai
        • Principal Investigator:
          • Alex Kolevzon, MD
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

No

Description

Key Inclusion Criteria:

  1. Is male or female, and 2 to 9 years of age at the time of JAG201 administration
  2. Has a molecular confirmation of a loss of function mutation in SHANK3 or a 22q13.3 deletion classified as a Class I deletion
  3. Has evidence of developmental/cognitive delay of at least 2 standard deviations (SD) below the mean (i.e., ≤ 70) via either Intelligence Quotient (IQ) OR Developmental Quotient (DQ) assessment (as applicable)
  4. Has an overall Phelan-McDermid Syndrome (PMS) Assessment of Severity (PMSA-S) Score of 3 or greater at Screening
  5. Willing to initiate structured therapies and continue for the duration of the study as determined by the specific therapist (structured therapies may include, at a minimum, physical therapy, occupational therapy, speech therapy, and applied behavior analysis)
  6. Is stable on any medication regimens (if being administered to control the signs and symptoms of underlying disease) for at least 3 months prior to the planned JAG201 study treatment
  7. If undergoing any kind of behavioral or therapeutic intervention, then the level of intervention must have remained stable for at least 3 months prior to the planned JAG201 study treatment (exclusive of school vacations/illness).
  8. Is a permanent legal resident of the U.S. residing within the continental U.S.

Key Exclusion Criteria:

A pediatric participant who meets any of the following criteria will be excluded from this study:

  1. Has history of developmental regression defined in this study as a prolonged loss of previously acquired skills (defined as skills maintained for at least 3 months) with loss of skills persisting for at least 3 months
  2. Has known or suspected prion disease (e.g., Creutzfeldt-Jakob Disease)
  3. Has poorly-controlled epilepsy (defined as an increase in the dose or addition of new anti-epileptic medications within the past 3 months) or any history of status epilepticus or seizure-induced hospitalizations within the last 12 months
  4. Has history of acute cerebrovascular episodes
  5. Has active autoimmune disease or prior treatment with immunomodulatory therapy, immunotherapy, and/or immunosuppressive drugs within 3 months prior to study enrollment (Note: Inhaled or topical steroids are permitted in the absence of active autoimmune disease)
  6. Has infection (viral, bacterial, or fungal) that requires treatment < 6 weeks before JAG201 administration (Note: JAG201 administration may be postponed until the infection has resolved and the participant is clinically stable)
  7. Has medical illness or other concern that would cause the Investigator to conclude that the participant will not be able to perform the study procedures or assessments or would confound interpretation of data obtained during assessments
  8. Has known allergy or hypersensitivity to prednisolone or other glucocorticosteroids, or their excipients
  9. Has received any vaccine < 6 weeks before JAG201 administration
  10. Has received any gene therapy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Sequential Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Pediatric Cohort 1
Starting Dose
Genetic: JAG201
Adeno-associated virus 2/9 expressing a miniature version of the human SHANK3 gene (AAV2/9-miniSHANK3)
Experimental: Pediatric Cohort 2
Escalated Dose
Genetic: JAG201
Adeno-associated virus 2/9 expressing a miniature version of the human SHANK3 gene (AAV2/9-miniSHANK3)

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Incidence of Adverse Events (AEs)
Time Frame: Enrollment to Month 60
Incidence, type, severity, and frequency of AEs
Enrollment to Month 60
Incidence of Serious Adverse Events (SAEs)
Time Frame: Enrollment to Month 60
Incidence, type, severity, and frequency of SAEs
Enrollment to Month 60
Clinically significant abnormalities in laboratory values
Time Frame: Enrollment to Month 60
Changes in clinically significant abnormalities in laboratory values
Enrollment to Month 60
Incidence of immunogenicity response abnormalities
Time Frame: Enrollment to Month 60
Incidence of anti-AAV9 antibodies, anti-transgene antibodies, and T-cell reactivity to transgene over time
Enrollment to Month 60

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change from Baseline in SAND
Time Frame: Enrollment to Month 60
To characterize the preliminary disease response to JAG201 by assessing the change from baseline in SAND (Sensory Assessment for Neurodevelopmental Disorders)
Enrollment to Month 60

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change from baseline in Vineland Adaptive Behavior Scales
Time Frame: Enrollment to Month 60
To characterize further the preliminary clinical activity of JAG201 by assessing change from baseline in Vineland Adaptive Behavior Scales, Third Edition
Enrollment to Month 60

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Jaguar Gene Therapy, LLC

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Dan Gallo, PhD, Jaguar Gene Therapy

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 7, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 1, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 1, 2031

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 16, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 25, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 28, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 3, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 2, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • JAG-201-CL-101

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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