protocolSection identificationModule nctId: NCT06363760, orgStudyIdInfo id: EDIT-301-LTFU-001, briefTitle: A Long-Term Follow-Up Study of Participants With Sickle Cell Disease or Transfusion Dependent β-Thalassemia Who Received EDIT-301, statusModule overallStatus: NOT_YET_RECRUITING, startDateStruct date: 2024-06-04, primaryCompletionDateStruct date: 2040-08, completionDateStruct date: 2040-08, studyFirstPostDateStruct date: 2024-04-12, lastUpdatePostDateStruct date: 2024-04-12, sponsorCollaboratorsModule leadSponsor name: Editas Medicine, Inc., class: INDUSTRY, descriptionModule briefSummary: The purpose of this study is to evaluate the long-term safety and efficacy of EDIT-301 in participants with severe sickle cell disease (SCD) or transfusion-dependent β-thalassemia (TDT) who have received EDIT-301., conditionsModule conditions: Sickle Cell Disease, conditions: Transfusion-dependent Beta-Thalassemia, conditions: Hemoglobinopathies, designModule studyType: OBSERVATIONAL, designInfo observationalModel: OTHER, timePerspective: PROSPECTIVE, enrollmentInfo count: 54, type: ESTIMATED, armsInterventionsModule interventions name: Safety and efficacy assessments, outcomesModule primaryOutcomes measure: Adverse events of special interest (AESI), primaryOutcomes measure: Adverse events of interest (AEI), primaryOutcomes measure: All-cause mortality, primaryOutcomes measure: Adverse events (AEs) related to EDIT-301, primaryOutcomes measure: Serious adverse events (SAEs), secondaryOutcomes measure: Proportion of SCD participants with severe vaso-occlusive events (sVOEs) over time post-EDIT-301 infusion, secondaryOutcomes measure: Proportion of SCD participants with vaso-occlusive events (VOEs) over time post-EDIT-301 infusion, secondaryOutcomes measure: Frequency of SCD-related transfusions over time post-EDIT-301 infusion for SCD participants, secondaryOutcomes measure: Proportion of TDT participants with sustained transfusion independence (TI) over time, secondaryOutcomes measure: Proportion of TDT participants with sustained transfusion reduction (TR) over time, secondaryOutcomes measure: Frequency of TDT-related transfusions over time post-EDIT-301 infusion for TDT participants, secondaryOutcomes measure: SCD and TDT: Percent of peripheral red blood cells (RBCs) containing HbF (F-cells) over time, secondaryOutcomes measure: SCD and TDT: Total hemoglobin (Hb) concentration (g/dL) over time, secondaryOutcomes measure: SCD and TDT: Proportion of alleles with intended genetic modification present in peripheral blood nucleated cells and bone marrow derived CD34+ over time, secondaryOutcomes measure: Average HbF (pg) per RBC over time for SCD participants, secondaryOutcomes measure: Complete Blood Count (CBC) red cell indices assay over time for SCD participants, secondaryOutcomes measure: Average HbF (pg) per F-cell over time for SCD participants, secondaryOutcomes measure: HbF and HbS concentration (g/dL) over time for SCD participants, secondaryOutcomes measure: The level of HbF production determined by fractionation of different forms of Hb (including but not limited to HbA, HbA2, HbC, HbD, HbE, and HbS) over time for SCD participants., secondaryOutcomes measure: Percentage of HbF over total non-transfused total Hb (non-transfused total Hb refers to the total g/dL of all Hb variants, excluding HbA) over time for TDT participants., secondaryOutcomes measure: HbF concentration (g/dL) over time for TDT participants, secondaryOutcomes measure: Iron overload of TDT participants, secondaryOutcomes measure: Proportion of TDT participants receiving iron chelation therapy over time., eligibilityModule sex: ALL, minimumAge: 12 Years, maximumAge: 50 Years, stdAges: CHILD, stdAges: ADULT, hasResults: False