Outpatient Treatment-Related Toxicity After Hospital Discharge Among Patients Receiving Lifileucel for Advanced Melanoma

PURPOSE: Although inpatient toxicity associated with tumor-infiltrating lymphocyte (TIL) therapy and interleukin-2 administration is well characterized, risks facing patients after hospital discharge are less understood. Better characterization of outpatient adverse events (AEs) could guide the optimal frequency and duration of follow-up in delivering care for this growing patient population. METHODS: We conducted a retrospective analysis of all patients with advanced melanoma discharged from Memorial Sloan Kettering Cancer Center after receiving investigational or commercial lifileucel from October 2020 to October 2024. We reviewed the incidence and timing of new treatment-related AEs (TRAEs), blood product administration, and readmission among all patients from the time of hospital discharge to the time of the start of a subsequent systemic therapy or death. RESULTS: Over a median follow-up of 5 months from discharge (IQR, 3-18), two patients (3.9%) developed new grade 3 TRAEs, including grade 3 neutropenia and hypoxia occurring 73 and 104 days after discharge, respectively. Four patients (7.8%) were readmitted for TRAEs including cytopenias, dyspnea, and syncope, at a median of 49 days (IQR, 22-81) after discharge. Twelve patients (24%) received outpatient transfusions, including a median of two units of packed RBCs (IQR, 1-4) and four units of platelets (IQR, 2-4). CONCLUSION: Overall, rates of new severe toxicity and treatment-related readmissions were low among patients discharged after lifileucel. These findings support individualized follow-up in this population compared with other cellular therapies and highlight the need for specific postdischarge guidelines for patients receiving TIL therapy.