A study to learn about the safety and efficacy of CTX001 (the "study drug product") to treat severe sickle cell disease in pediatric subjects

A Phase 3 Study to Evaluate the Safety and Efficacy of a Single Dose of CTX001 in Pediatric Subjects With Severe Sickle Cell Disease

Status

Active, not recruiting

Phases

Phase 3

Study type

Interventional

Source

EU CTR

Registry ID

EUCTR2021-002173-26-DE

Enrollment

Registered

2021-08-27

Start date

2022-03-17

Completion date

Unknown

Last updated

2024-12-03

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Severe Sickle Cell Disease (SCD) MedDRA version: 21.0 Level: PT Classification code 10040641 Term: Sickle cell anaemia System Organ Class: 10010331 - Congenital, familial and genetic disorders

Interventions

Product Name: Exagamglogene autotemcel (Exa-cel) Product Code: CTX001 Pharmaceutical Form: Dispersion for infusion INN or Proposed INN: Autologous CRISPR-Cas9 Modified CD34+ Human Hematopoietic Stem a

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: • Subjects 2 through 11 years of age, inclusive, on the date of informed consent • Diagnosis of severe sickle cell disease as defined by: • Documented severe sickle cell disease genotype • History of at least two severe vaso-occlusive crisis events per year for the previous two years prior to enrollment • Eligible for autologous stem cell transplant as per investigators judgment Other protocol defined inclusion criteria may apply Are the trial subjects under 18? yes Number of subjects for this age range: 15 F.1.2 Adults (18-64 years) no F.1.2.1 Number of subjects for this age range F.1.3 Elderly (>=65 years) no F.1.3.1 Number of subjects for this age range

Exclusion criteria

Exclusion criteria: • An available 10/10 human leukocyte antigen (HLA)-matched related donor • Prior hematopoietic stem cell transplant (HSCT) • Clinically significant and active bacterial, viral, fungal, or parasitic infection Other protocol defined exclusion criteria may apply

Design outcomes

Primary

Measure	Time frame
Main Objective: Evaluate the efficacy of a single dose of autologous CRISPR-Cas9 modified CD34+ human hematopoietic stem and progenitor cells (hHSPCs) (CTX001) in pediatric subjects with severe sickle cell disease ;Secondary Objective: • Evaluate the safety and tolerability of a single dose of CTX001 • Assess the effects of infusion of CTX001 on disease-specific events and clinical status • Quantify gene editing efficiency;Primary end point(s): Proportion of subjects who do not have any severe VOCs for at least 12 consecutive months (VF12) after CTX001 infusion. The evaluation of VF12 starts 60 days after the last RBC transfusion for post-transplant support or SCD disease management.;Timepoint(s) of evaluation of this end point: Up to 24 months	—

Measure

Time frame

Main Objective: Evaluate the efficacy of a single dose of autologous CRISPR-Cas9 modified CD34+ human hematopoietic stem and progenitor cells (hHSPCs) (CTX001) in pediatric subjects with severe sickle cell disease ;Secondary Objective: • Evaluate the safety and tolerability of a single dose of CTX001 • Assess the effects of infusion of CTX001 on disease-specific events and clinical status • Quantify gene editing efficiency;Primary end point(s): Proportion of subjects who do not have any severe VOCs for at least 12 consecutive months (VF12) after CTX001 infusion. The evaluation of VF12 starts 60 days after the last RBC transfusion for post-transplant support or SCD disease management.;Timepoint(s) of evaluation of this end point: Up to 24 months

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Secondary

Measure	Time frame
Secondary end point(s): • Safety and tolerability of CTX001 based on adverse events (AEs), clinical laboratory values, vital signs, neutrophil engraftment, platelet engraftment, transplant-related mortality (TRM), and all-cause mortality • Proportion of subjects free from inpatient hospitalization for severe VOCs for at least 12 months (HF12) after CTX001 infusion. The evaluation of HF12 starts 60 days after last RBC transfusion for post-transplant support or SCD disease management. • Relative reduction from baseline in annualized rate of severe VOCs up to 24 months after CTX001 infusion. The evaluation starts 60 days after last RBC transfusion for posttransplant support or SCD disease management. • Duration of severe VOC free in subjects who have achieved VF12 • Relative reduction from baseline in annualized rate of inpatient hospitalizations for severe VOCs up to 24 months after CTX001 infusion. The evaluation starts 60 days after last RBC transfusion for post-transplant support or SCD disease management. • Relative reduction from baseline in annualized duration of hospitalization for severe VOCs up to 24 months after CTX001 infusion. The evaluation starts 60 days after last RBC transfusion for post-transplant support or SCD disease management. • Proportion of subjects with sustained HbF =20% at the time of analysis for at least 3 months, 6 months, or 12 months. The evaluation starts 60 days after last RBC transfusion for post-transplant support or SCD disease management. • Proportion of subjects with sustained HbF =30% at the time of analysis for at least 3 months, 6 months, or 12 months. The evaluation starts 60 days after last RBC transfusion for post-transplant support or SCD disease management. • Time for subjects to reach HbF =20% • Time for subjects to reach HbF =30% • Relative reduction from baseline in annualized volume of units of RBCs transfusions • HbF concentrations over time • Hb concentrations over time • Change in proportion of circulating erythroc	—

Measure

Time frame

Secondary end point(s): • Safety and tolerability of CTX001 based on adverse events (AEs), clinical laboratory values, vital signs, neutrophil engraftment, platelet engraftment, transplant-related mortality (TRM), and all-cause mortality • Proportion of subjects free from inpatient hospitalization for severe VOCs for at least 12 months (HF12) after CTX001 infusion. The evaluation of HF12 starts 60 days after last RBC transfusion for post-transplant support or SCD disease management. • Relative reduction from baseline in annualized rate of severe VOCs up to 24 months after CTX001 infusion. The evaluation starts 60 days after last RBC transfusion for posttransplant support or SCD disease management. • Duration of severe VOC free in subjects who have achieved VF12 • Relative reduction from baseline in annualized rate of inpatient hospitalizations for severe VOCs up to 24 months after CTX001 infusion. The evaluation starts 60 days after last RBC transfusion for post-transplant support or SCD disease management. • Relative reduction from baseline in annualized duration of hospitalization for severe VOCs up to 24 months after CTX001 infusion. The evaluation starts 60 days after last RBC transfusion for post-transplant support or SCD disease management. • Proportion of subjects with sustained HbF =20% at the time of analysis for at least 3 months, 6 months, or 12 months. The evaluation starts 60 days after last RBC transfusion for post-transplant support or SCD disease management. • Proportion of subjects with sustained HbF =30% at the time of analysis for at least 3 months, 6 months, or 12 months. The evaluation starts 60 days after last RBC transfusion for post-transplant support or SCD disease management. • Time for subjects to reach HbF =20% • Time for subjects to reach HbF =30% • Relative reduction from baseline in annualized volume of units of RBCs transfusions • HbF concentrations over time • Hb concentrations over time • Change in proportion of circulating erythroc

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Countries

France, Germany, Italy, United Kingdom, United States

Contacts

Public ContactClinical Trials and Medical Info

Vertex Pharmaceuticals Incorporated

medicalinfo@vrtx.com+1877634 8789

Outcome results

None listed

Source: EU CTR (via WHO ICTRP) · Data processed: Feb 4, 2026