A Phase 3 interventional study of Exa-cel in Sickle Cell Disease, sponsored by Vertex Pharmaceuticals Incorporated. Withdrawn. Open to participants aged 12 Years to 35 Years. Per ClinicalTrials.gov, last updated 2026-03-25.
Sponsored by Vertex Pharmaceuticals Incorporated · Phase 3, Interventional, and Treatment
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).
1,103 studies on the registry are indexed under Anemia, Sickle Cell; 235 are open to participants now.
Browse Anemia, Sickle Cell studies →Vertex Pharmaceuticals Incorporated is the lead sponsor of 243 studies on the registry; 19 are open to participants now.
Of its 102 completed or terminated interventional studies of FDA-regulated products, 49 (48%) have results posted.
Counted across the registry records on this site, refreshed daily.
Key Inclusion Criteria:
Key Exclusion Criteria:
Other protocol defined Inclusion/Exclusion criteria may apply.
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
Administered by intravenous (IV) infusion following myeloablative conditioning with busulfan.
Also known as: Exagamglogene autotemcel, CTX001
Proportion of Participants with an Average Fetal Hemoglobin (HbF) Greater Than or Equal To (>=) 20 percent (%) on or After 6 Months
Time frame: From 60 Days after Last Red Blood Cell (RBC) transfusion up to 24 Months after exa-cel infusion
Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)
Time frame: 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)
Time frame: Within 42 Days After exa-cel Infusion
Time to Neutrophil Engraftment
Time frame: Up to 24 months After exa-cel Infusion
Time to Platelet Engraftment
Time frame: Up to 24 months After exa-cel Infusion
Incidence of Transplant-Related Mortality (TRM)
Time frame: Up to 100 Days After exa-cel Infusion
Incidence of Transplant-Related Mortality (TRM)
Time frame: Within 12 Months After exa-cel Infusion
Incidence of All-cause Mortality
Time frame: From Signing of Informed Consent up to 24 Months After exa-cel Infusion
Proportion of Participants With No Severe Vaso-Occlusive Crises (VOCs) for At least 12 Months (VF12)
Time frame: From 60 Days after Last RBC transfusion up to 24 Months After exa-cel Infusion
Proportion of Participants Free from Inpatient Hospitalization For Severe VOCs Sustained for At least 12 Months (HF12)
Time frame: From 60 Days after Last RBC transfusion up to 24 Months After exa-cel Infusion
Relative Reduction in Annualized Rate of Severe VOCs
Time frame: From Baseline up to 24 Months After exa-cel Infusion
Duration of Severe VOC Free in Participants who Have Achieved VF12
Time frame: From 60 Days after Last RBC transfusion up to 24 Months After exa-cel Infusion
Relative Reduction in Rate of Inpatient Hospitalizations for Severe VOCs
Time frame: From Baseline up to 24 Months After exa-cel Infusion
Relative Reduction in Annualized Duration of Hospitalization for Severe VOCs
Time frame: From Baseline up to 24 Months After exa-cel Infusion
Proportion of Participants With Sustained HbF >= 20 % for At least 3, 6, or 12 months
Time frame: From 60 Days after Last RBC transfusion up to 24 Months After exa-cel Infusion
Relative Reduction in Annualized Volume of RBC Transfusions
Time frame: From Baseline Up To 24 Months After exa-cel Infusion
HbF Concentration Over Time
Time frame: Up To 24 Months After exa-cel Infusion
Total Hemoglobin (Hb) Concentration Over Time
Time frame: Up To 24 Months After exa-cel Infusion
Change In Reticulocyte Count Over Time
Time frame: From Baseline Up To 24 Months After exa-cel Infusion
Change in Indirect Bilirubin Over Time
Time frame: From Baseline Up To 24 Months After exa-cel Infusion
Change in Haptoglobin Over Time
Time frame: From Baseline Up To 24 Months After exa-cel Infusion
Change in Lactate dehydrogenase (LDH) Over Time
Time frame: From Baseline Up To 24 Months After exa-cel Infusion
Time to First Detectable Haptoglobin
Time frame: Up to 24 Months After exa-cel Infusion
Time to First Normalized LDH
Time frame: Up to 24 Months After exa-cel Infusion
Proportion of Alleles With Intended Genetic Modification Present in Peripheral Blood Over Time
Time frame: Up To 24 Months After exa-cel Infusion
Proportion of Alleles With Intended Genetic Modification Present in CD34+ Cells of the Bone Marrow Over Time
Time frame: Up To 24 Months After exa-cel Infusion
Change in Pain Scale (11-point numerical rating scale (NRS)) Assessment Over Time In Adults (>=18 Years)
Time frame: From Baseline Up To 24 Months After exa-cel Infusion
Change in Functional Assessment of Cancer Therapy-Bone Marrow Transplant (FACT-BMT) Over Time In Adults (>=18 Years)
Time frame: From Baseline Up To 24 Months After exa-cel Infusion
Change in Adult Sickle Cell Quality of Life Measurement System (ASCQ-Me)
Time frame: From Baseline Up To 24 Months After exa-cel Infusion
Change in Pain Scale (11-point NRS) Assessment Over Time In Adolescents (12 to <18 years of age)
Time frame: From Baseline Up To 24 Months After exa-cel Infusion
Change in Pediatric Quality of Life Inventory (PedsQL; self-report and parent proxy versions) Generic Core In Adolescents (12 to <18 years of age)
Time frame: From Baseline Up To 24 Months After exa-cel Infusion
Change in PedsQL SCD module (self-report and parent proxy versions) In Adolescents (12 to <18 years of age)
Time frame: From Baseline Up To 24 Months After exa-cel Infusion
No study locations are listed for this record.
Plan to share: No — Details on Vertex data sharing criteria and process for requesting access can be found at: https://www.vrtx.com/our-science/clinical-trials-data-sharing/
No publications or documents are linked to this record.
This study is withdrawn, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.
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Vertex Pharmaceuticals Incorporated