The purpose of the ALPHA study is to assess the safety, efficacy, cell kinetics and immunogenicity of ALLO-501 in adults with relapsed or refractory large B-cell lymphoma or follicular lymphoma after a lymphodepletion regimen comprising fludarabine, cyclophosphamide, and ALLO-647.

Inclusion Criteria:

• Histological or cytological diagnosis of Large B-cell Lymphoma (LBCL) or Follicular Lymphoma.
• Relapse or refractory disease after at least 2 lines of chemotherapy
• At least 1 measurable lesion at time of screening.
• Eastern Cooperative Oncology Group Performance Status of 0 or 1.
• Adequate hematological, renal, liver, pulmonary, and cardiac functions.

Exclusion Criteria:

• Current or history of central nervous system (CNS) lymphoma.
• Clinically significant CNS dysfunction.
• ASCT within last 6 weeks or allogeneic HSCT within last 3 months prior to ALLO-647.
• Prior treatment with anti-CD19 therapy, any gene therapy, any genetically modified cell therapy or adoptive T cell therapy
• Systemic anticancer therapy within 2 weeks prior to study entry.
• On-going treatment with immunosuppressive agents.
• Active acute or chronic graft versus host disease (GvHD), or GvHD requiring immunosuppressive treatment within 4 weeks of enrollment.
• Any form of primary or acquired immunodeficiency (e.g., severe combined immunodeficiency disease).
• Current thyroid disorder (including hyperthyroidism), except for subjects with hypothyroidism controlled on a stable dose of hormone replacement therapy.
• Patients unwilling to participate in an extended safety monitoring period