• Male or female ≥ 18 years of age.

• Patients with r/r TCL per WHO 2022 criteria.

∙ r/r CTCL that has failed ≥ 2 prior lines of standard of care (SoC) therapy.

‣ r/r PTCL that has failed ≥ 1 prior lines of SoC therapy. Note: patients with CD30+ disease should have received brentuximab vedotin.

• Has available tumor tissue or is willing to undergo a biopsy procedure.

• CD5 positivity confirmed by local laboratory using an approved diagnostic test or LDT. CD5 positivity is currently defined as having ≥ 50% CD5 expression. An exploratory cohort will enroll patients with CD5 expression below 50%.

• Karnofsky performance score ≥ 70% or higher.

• Prior CAR T-cell therapy must have occurred \> 60 days prior to study enrollment and must have no evidence of CAR persistence.

• Measurable or detectable disease

∙ PTCL per Lugano criteria

‣ CTCL per Global (ISCL/EORTC/USCCL) criteria.

• Prior autologous or allogenic hematopoietic stem cell transplant (HSCT) must have occurred more than 60 days prior to study enrollment.

• Adequate bone marrow function defined as:

∙ Absolute neutrophil count (ANC) ≥ 1500/μL (≥ 1000/μL for patients with prior HSCT or marrow involvement)

‣ Absolute lymphocyte count ≥200 cells/μL

‣ Hemoglobin ≥ 8 g/dL (transfusion permitted)

‣ Platelet count ≥ 75 000/μL (≥50 000/μL for patients with marrow involvement).

⁃ Organ function as follows:

• Cardiac: left ventricular ejection fraction (LVEF) ≥ 50% by Echo or radionuclide scan.

∙ Pulmonary: oxygen saturation ≥ 92% (room air).

∙ Renal: calculated creatinine clearance \> 30 mL/min.

∙ Liver:

‣ Total bilirubin \< 1.5 x ULN (\< 2 × upper limit of normal (ULN)) if liver involvement).

⁃ If no liver involvement and total bilirubin ≥1.5 x ≤ ULN, direct bilirubin \< ULN (Gilbert syndrome)

⁃ Aspartate aminotransferase / alanine aminotransferase \< 3 × ULN (5 x ULN if liver involvement).

⁃ Albumin \> 2.5 g/dL.

⁃ For females of childbearing potential (defined as \< 24 months of amenorrhea or not surgically sterile \[absence of ovaries and/or uterus\]), a negative serum pregnancy test must be documented at screening, and prior to lymphodepletion (conditioning).

⁃ For females of childbearing potential and males, a highly effective method of contraception together with a barrier method must be used from the start of lymphodepletion (conditioning) and for at least 12 months after the last dose of study agent.