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

Phase 3
Not yet recruiting
Conditions
Sickle Cell Disease
Interventions
Biological: Exa-cel
Registration Number
NCT05951205
Lead Sponsor
Vertex Pharmaceuticals Incorporated
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).

Detailed Description

Not available

Recruitment & Eligibility

Status
NOT_YET_RECRUITING
Sex
All
Target Recruitment
12
Inclusion Criteria
  • Participants with documented βS/βC (HbSC) genotype
  • Participants must be eligible for autologous stem cell transplant as per investigator's judgment

Key

Exclusion Criteria
  • 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.

Other protocol defined Inclusion/Exclusion criteria may apply.

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
Exa-celExa-celParticipants 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.
Primary Outcome Measures
NameTimeMethod
Proportion of Participants with an Average Fetal Hemoglobin (HbF) Greater Than or Equal To (>=) 20 percent (%) on or After 6 MonthsFrom 60 Days after Last Red Blood Cell (RBC) transfusion up to 24 Months after exa-cel infusion
Secondary Outcome Measures
NameTimeMethod
Proportion of Participants With No Severe Vaso-Occlusive Crises (VOCs) for At least 12 Months (VF12)From 60 Days after Last RBC transfusion up to 24 Months After exa-cel Infusion
Duration of Severe VOC Free in Participants who Have Achieved VF12From 60 Days after Last RBC transfusion up to 24 Months After exa-cel Infusion
Time to Neutrophil EngraftmentUp to 24 months After exa-cel Infusion
Relative Reduction in Annualized Volume of RBC TransfusionsFrom Baseline Up To 24 Months After exa-cel Infusion
Change in Haptoglobin Over TimeFrom Baseline 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)From Baseline Up To 24 Months After exa-cel Infusion
Proportion of Participants With Sustained HbF >= 20 % for At least 3, 6, or 12 monthsFrom 60 Days after Last RBC transfusion up to 24 Months After exa-cel Infusion
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
Incidence of All-cause MortalityFrom Signing of Informed Consent up to 24 Months After exa-cel Infusion
Relative Reduction in Annualized Duration of Hospitalization for Severe VOCsFrom Baseline up to 24 Months After exa-cel Infusion
Total Hemoglobin (Hb) Concentration Over TimeUp To 24 Months After exa-cel Infusion
Change in Lactate dehydrogenase (LDH) Over TimeFrom Baseline Up To 24 Months After exa-cel Infusion
Time to First Normalized LDHUp to 24 Months After exa-cel Infusion
Proportion of Alleles With Intended Genetic Modification Present in Peripheral Blood Over TimeUp 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
Incidence of Transplant-Related Mortality (TRM)Within 12 Months After exa-cel Infusion
Proportion of Participants Free from Inpatient Hospitalization For Severe VOCs Sustained for At least 12 Months (HF12)From 60 Days after Last RBC transfusion up to 24 Months After exa-cel Infusion
Relative Reduction in Annualized Rate of Severe VOCsFrom Baseline up to 24 Months After exa-cel Infusion
Relative Reduction in Rate of Inpatient Hospitalizations for Severe VOCsFrom Baseline up to 24 Months After exa-cel Infusion
HbF Concentration Over TimeUp To 24 Months After exa-cel Infusion
Change in Indirect Bilirubin Over TimeFrom 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)From Baseline Up To 24 Months After exa-cel Infusion
Time to Platelet EngraftmentUp to 24 months After exa-cel Infusion
Change In Reticulocyte Count Over TimeFrom Baseline Up To 24 Months After exa-cel Infusion
Time to First Detectable HaptoglobinUp to 24 Months After exa-cel Infusion
Proportion of Alleles With Intended Genetic Modification Present in CD34+ Cells of the Bone Marrow Over TimeUp To 24 Months After exa-cel Infusion
Change in Adult Sickle Cell Quality of Life Measurement System (ASCQ-Me)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)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)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)From Baseline Up To 24 Months After exa-cel Infusion
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