A Long-Term Follow-Up Study of Participants With Sickle Cell Disease or Transfusion Dependent β-Thalassemia Who Received EDIT-301

A Long-Term Follow-Up Study of Participants With Sickle Cell Disease or Transfusion Dependent β-Thalassemia Who Received EDIT-301

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.

This is a non-interventional, multicenter study evaluating the long-term safety and efficacy of EDIT-301 in participants with severe sickle cell disease (SCD) or transfusion dependent b-thalassemia (TDT) who received EDIT-301 in parent studies EM-SCD-301-001 (NCT04853576) or EDIT-301-BThal-001 (NCT05444894). No investigational drug product will be administered in the LTFU study.

Inclusion Criteria:

• Participant must have received an EDIT-301 infusion as part of a clinical study.
• Participant or legal representative/guardian (if applicable) must sign and date the informed consent form (ICF) or assent, if applicable for this long-term follow-up study.

Exclusion Criteria:

• Participant is still actively enrolled in an EDIT-301 treatment study and has not yet met eligibility for long term follow-up in this study.