Evaluation of Efficacy and Safety of a Single Dose of Exa-cel in Participants With Severe Sickle Cell Disease, βS/ βC Genotype

NCT05951205 | Withdrawn Phase 3 FDA Drug

• 3 other identifiers: VX21-CTX001-1712023-503247-34-002021-006375-41
• Study Type: interventional
• Target: N/A
• Locations: 0 countries
• Sites: N/A

Brief Summary

The purpose of the study is to evaluate the efficacy and safety of CTX001 (exa-cel) in adolescent and adult participants with severe sickle cell disease (SCD), βS/βC genotype (HbSC).

Conditions

Sickle Cell Disease

Outcome Measures

Primary Outcomes (1)

• Proportion of Participants with an Average Fetal Hemoglobin (HbF) Greater Than or Equal To (>=) 20 percent (%) on or After 6 Months

  From 60 Days after Last Red Blood Cell (RBC) transfusion up to 24 Months after exa-cel infusion

Secondary Outcomes (31)

• Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)

  From Signing of Informed Consent up to 24 Months After exa-cel Infusion

• Proportion of Participants With Neutrophil Engraftment (First day of 3 Consecutive Measurements of Absolute Neutrophil Count (ANC) >=500 per Microliter [mcgL] on 3 Different Days)

  Within 42 Days After exa-cel Infusion

• Time to Neutrophil Engraftment

  Up to 24 months After exa-cel Infusion

• Time to Platelet Engraftment

  Up to 24 months After exa-cel Infusion

• Incidence of Transplant-Related Mortality (TRM)

  Up to 100 Days After exa-cel Infusion

Study Arms (1)

Exa-cel

EXPERIMENTAL

Participants will receive a single infusion of exa-cel (autologous CD34+ hHSPCs modified with CRISPR-Cas9 at the erythroid lineage-specific enhancer of the BCL11A gene) through a central venous catheter.

Biological: Exa-cel

Interventions

Exa-cel BIOLOGICAL

Administered by intravenous (IV) infusion following myeloablative conditioning with busulfan.

Also known as: Exagamglogene autotemcel, CTX001

Exa-cel

Eligibility Criteria

• Age: 12 Years - 35 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• Participants with documented βS/βC (HbSC) genotype
• Participants must be eligible for autologous stem cell transplant as per investigator's judgment

You may not qualify if:

• A willing and healthy 10/10 human leukocyte antigen (HLA)-matched related donor is available per investigator's judgement
• Participants with prior hematopoietic stem cell transplant (HSCT)
• Treatment with regular RBC transfusions that, in the opinion of the investigator, cannot be interrupted after engraftment.

Sponsors & Collaborators

• Vertex Pharmaceuticals Incorporated: lead

MeSH Terms

Conditions

Anemia, Sickle Cell

Interventions

exagamglogene autotemcel

Condition Hierarchy (Ancestors)

Anemia, Hemolytic, Congenital; Anemia, Hemolytic; Anemia; Hematologic Diseases; Hemic and Lymphatic Diseases; Hemoglobinopathies; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 23, 2023
• First Posted: July 18, 2023
• Study Start (Estimated): July 31, 2027
• Primary Completion (Estimated): December 31, 2033
• Study Completion (Estimated): December 31, 2033
• Last Updated: March 25, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share