This is a Long-term Follow-up (LTFU) study in patients who received BEAM-101 in the parent study (Study BTX-AUT-001). Eligible patients who received BEAM-101 will be asked to participate in this LTFU study prior to completing Study BTX-AUT-001. Patients who enter into this study will be followed for 13 years (a total of 15 years after receiving BEAM-101).

Patients who were treated with BEAM-101 in Study BTX-AUT-001 will be asked to sign an informed consent form (ICF) to enter this LTFU study (during the EOS/Month 24 visit for BTX-AUT-001). Patients in this study will have periodic safety and efficacy assessments per the schedule of assessments (SoA). Visits will occur annually through Year 5 following BEAM-101 administration and then every 3 years through Year 11, with a final visit at Year 15. Virtual/phone call check-in visits will occur every 6 months through Year 5 and then annually thereafter.

Inclusion Criteria:

1. Have received BEAM-101 in Study BTX-AUT-001 and are in the process of completing that study's end-of-study (EOS) visit.
2. Provide signed, written informed consent according to local institutional review board (IRB)/independent ethics committee (IEC) and institutional requirements.

Exclusion Criteria:

• There are no exclusion criteria for this study.

The study population consists of participants enrolled at sites from the parent study (BTX-AUT-001) who meet the criteria for long-term follow-up