Key Inclusion Criteria:

   - Histologically confirmed advanced (unresectable or metastatic) cutaneous melanoma.

   - Cohort 1: Disease that is relapsed after or refractory to at least 1 prior line of
   systemic therapy that must include a PD-1 inhibitor and, if positive for proto-
   oncogene BRAF V600 activating mutation, targeted therapy.

   - Cohort 2: Disease that is persistent after discontinuing PD-1 due to toxicity.
   Patients with a proto-oncogene BRAF V600 activating mutation must have progressed
   after targeted therapy.

   - Cohort 3: Disease that is stable (SD) after at least 4 doses of a PD-1 inhibitor.
   Patients with a proto-oncogene BRAF V600 activating mutation must have progressed
   after targeted therapy.

   - Medically suitable for surgical resection of tumor tissue

   - Following tumor resection for TIL harvest, will have, at minimum, 1 remaining
   measurable lesion as identified by CT or MRI per Response Evaluation Criteria in Solid
   Tumors (RECIST) v1.1

   - Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1

   - Adequate bone marrow and organ function

Key Exclusion Criteria:

   - History of another primary malignancy within the previous 3 years

   - Melanoma of uveal, acral, or mucosal origin

   - Previously received an allogeneic stem cell transplant or organ allograft

   - Previously received TIL or engineered cell therapy ( eg, CAR T-cell)

   - Significant cardiac disease

   - Stroke or transient ischemic attack within 12 months of enrollment

   - History of significant central nervous system (CNS) disorder

   - Symptomatic and/or untreated CNS metastases

   - History of significant autoimmune disease within 2 years prior to enrollment

   - Known history of severe, immediate hypersensitivity reaction attributed to
   cyclophosphamide, fludarabine, or IL-2.