Skip to main content
OpenTrials
Enrolling by Invitation

NCT Number: NCT04208529

A Long-term Follow-up Study in Participants Who Received CTX001

This is a multi-site, open- label rollover study to evaluate the long-term safety and efficacy of CTX001 in pediatric and adult participants who received CTX001 in parent studies 111 (NCT03655678) 141 (NCT05356195) or 161 (NCT05477563) (transfusion-dependent β-thalassemia [TDT] studies) or Study 121 (NCT03745287) or 151 (NCT05329649) or 161(NCT05477563) (severe sickle cell disease [SCD] studies).

Enrolling by Invitation

Interested in participating?

Request Info

Key information

Conditions

Beta-Thalassemia Anemia Anemia, Hemolytic Anemia, Hemolytic, Congenital Anemia, Sickle Cell Congenital, Hereditary, and Neonatal Diseases and Abnormalities Genetic Diseases, Inborn Hematologic Diseases Hemic and Lymphatic Diseases Hemoglobinopathies Sickle Cell Anemia Sickle Cell Disease Thalassemia

Age range

2 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 3

Primary location

Hopital Universitaire des Enfants Reine Fabiola (HUDERF) - Hematology, Brussels, Belgium

Loading trial locations.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Participants (or his or her legally appointed and authorized representative or guardian) must sign and date informed consent form (ICF) and, where applicable, an assent form
  • Participants must have received CTX001 infusion in a parent study

Exclusion criteria

  • There are no exclusion criteria

Treatment and study plan

CTX001

Biological

CTX001 infusion.

Other names: Exagamglogene autotemcel, Exa-cel

Primary outcomes

  1. New malignancies

    Time frame: Signing of informed consent up to 15 years post CTX001 infusion

  2. New or worsening hematologic disorders

    Time frame: Signing of informed consent up to 15 years post CTX001 infusion

  3. All-cause mortality

    Time frame: Signing of informed consent up to 15 years post CTX001 infusion

  4. Serious adverse events (SAEs)

    Time frame: Signing of informed consent up to 15 years post CTX001 infusion

  5. CTX001-related adverse events (AEs)

    Time frame: Signing of informed consent up to 15 years post CTX001 infusion

Secondary outcomes

  1. TDT and SCD: Total Hemoglobin (Hb) concentration over time

    Time frame: Up to 15 years post CTX001 infusion

  2. TDT and SCD: Fetal Hemoglobin (HbF) concentration over time

    Time frame: Up to 15 years post CTX001 infusion

  3. TDT and SCD: Proportion of alleles with intended genetic modification present in peripheral blood over time

    Time frame: Up to 15 years post CTX001 infusion

  4. TDT and SCD: Proportion of alleles with intended genetic modification present in CD34+ cells of the bone marrow over time

    Time frame: Up to 15 years post CTX001 infusion

  5. TDT and SCD: Change in patient-reported outcome (PRO) over time in participants ≥18 years of age assessed using EuroQol quality of life scale (EQ-5D-5L) for participants from study 111 and 121 only

    Time frame: Up to 5 years post CTX001 infusion

  6. TDT and SCD: Change in PROs over time in participants ≥18 years of age assessed using functional assessment of cancer therapy-bone marrow transplant (FACT-BMT) questionnaire for participants from study 111, 121 and 161 only

    Time frame: Up to 5 years post CTX001 infusion

  7. TDT and SCD: Change in PROs over time in participants <18 years assessed using EQ-5D-Youth (EQ-5D-Y) from study 111,121,141 and 151 only

    Time frame: Up to 5 years post CTX001 infusion

  8. TDT and SCD: Change in PROs over time in participants <18 years assessed using pediatric quality of life inventory (PedsQL) Core

    Time frame: Up to 5 years post CTX001 infusion

  9. TDT: Proportion of participants achieving transfusion independence for at least 12 consecutive months (TI12)

    Time frame: From 60 days after last RBC transfusion up to 15 years post-CTX001 infusion

  10. TDT: Proportion of participants achieving transfusion independence for at least 6 consecutive months (TI6)

    Time frame: From 60 days after last RBC transfusion up to 15 years post-CTX001 infusion

  11. TDT: Proportion of participants achieving at least 95%, 90%, 85%, 75%, 50% reduction from baseline in annualized volume of RBC transfusions starting after month 10 after CTX001 infusion for participants who have not achieved TI12

    Time frame: From Month 10 up to 15 years post-CTX001 infusion

  12. TDT: Duration of transfusion free in participants who have achieved TI12

    Time frame: From 60 days after last RBC transfusion up to 15 years post CTX001 infusion

  13. TDT: Relative reduction from baseline in annualized volume of RBC transfusions starting after Month 10 after CTX001 infusion for participants who have not achieved TI12

    Time frame: From Month 10 up to 15 years post-CTX001 infusion

  14. TDT: Iron overload as measured by liver iron concentration (LIC), cardiac iron concentration (CIC), and ferritin for beta-Thalassemia participants

    Time frame: Up to 8 years post CTX001 infusion for LIC; up to 5 years post CTX001 infusion for CIC and up to 15 years post CTX001 infusion for ferritin

  15. TDT: Proportion of participants receiving iron removal therapy over time

    Time frame: Up to 15 years post CTX001 infusion

  16. SCD: Proportion of participants who have not experienced any severe vaso-occlusive crises (VOC) for at least 12 consecutive months (VF12)

    Time frame: From 60 days after last RBC transfusion up to 15 years post-CTX001 infusion

  17. SCD: Proportion of participants with SCD 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 15 years post-CTX001 infusion

  18. SCD: Proportion of participants with at least 90 percent (%), 80%, 75% or 50% reduction in annualized rate of severe VOCs

    Time frame: From 60 days after last RBC transfusion up to 15 years post-CTX001 infusion

  19. SCD: Relative change from baseline in annualized rate of severe VOCs

    Time frame: From 60 days after last RBC transfusion up to 15 years post-CTX001 infusion

  20. SCD: Duration of severe VOC free in participants who have achieved VF12

    Time frame: From 60 days after last RBC transfusion up to 15 years post CTX001 infusion

  21. SCD: Relative change from baseline in rate of inpatient hospitalizations for severe VOCs

    Time frame: From 60 days after last RBC transfusion up to 15 years post-CTX001 infusion

  22. SCD: Relative change from baseline in annualized duration of hospitalization for severe VOCs

    Time frame: From 60 days after last RBC transfusion up to 15 years post-CTX001 infusion

  23. SCD: Proportion of participants with sustained HbF ≥20% for at least 3 months

    Time frame: From 60 days after last RBC transfusion up to 15 years post-CTX001 infusion

  24. SCD: Proportion of participants with sustained HbF ≥20% for at least 6 months

    Time frame: From 60 days after last RBC transfusion up to 15 years post-CTX001 infusion

  25. SCD: Proportion of participants with sustained HbF ≥20% for at least 12 months

    Time frame: From 60 days after last RBC transfusion up to 15 years post-CTX001 infusion

  26. SCD: Change in volume of RBCs transfused for SCD-related indications over time

    Time frame: Up to 15 years post CTX001 infusion

  27. SCD: Change from baseline in reticulocytes/erythrocytes over time

    Time frame: From baseline up to 15 years post CTX001 infusion

  28. SCD: Change from baseline in lactate dehydrogenase (LDH) over time

    Time frame: From baseline up to 15 years post CTX001 infusion

  29. SCD: Change from baseline in haptoglobin over time

    Time frame: From baseline up to 15 years post CTX001 infusion

  30. SCD: Change from baseline in total bilirubin over time

    Time frame: From baseline up to 15 years post CTX001 infusion

  31. SCD: Change from baseline in indirect bilirubin over time

    Time frame: From baseline up to 15 years post CTX001 infusion

  32. SCD: Change in SCD-specific PROs over time in participants ≥18 years of age assessed using adult sickle cell quality of life measurement system (ASCQ-Me) (participants from Study 121 and 161 only)

    Time frame: Up to 5 years post CTX001 infusion

  33. SCD: Change in SCD-specific PROs over time in participants <18 years of age assessed using PedsQL Generic Core SCD module from studies 111,121,141,151 and 161

    Time frame: Up to 5 years post CTX001 infusion

  34. SCD: Change in PRO over time assessed using 11-point numerical rating scale (NRS)

    Time frame: Up to 5 years post CTX001 infusion

  35. SCD: Change in PROs over time assessed using Wong Baker FACES pain scale

    Time frame: Up to 5 years post CTX001 infusion

  36. SCD: Change in PROs over time using face, legs, activity, cry, consolability (FLACC) behavioral pain scale

    Time frame: Up to 5 years post CTX001 infusion

Sponsors and collaborators

Lead sponsor

Vertex Pharmaceuticals Incorporated

Industry

Collaborators

  • CRISPR Therapeutics

Registry information

Official study title

A Long-term Follow-up Study of Subjects With β-thalassemia or Sickle Cell Disease Treated With Autologous CRISPR-Cas9 Modified Hematopoietic Stem Cells (CTX001)

Important dates

Study start
2021
Primary completion
2039
Study completion
2039
First posted
Dec 23, 2019
Registry last updated
Mar 25, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.