Severe treatment-related adverse events (TRAEs) and readmissions were uncommon after hospital discharge among patients with advanced melanoma who received lifileucel (Amtagvi), according to findings published in JCO Oncology Practice. However, nearly 1 in 4 patients required outpatient blood transfusions, highlighting the need for continued monitoring following tumor-infiltrating lymphocyte (TIL) therapy.¹

The retrospective study evaluated postdischarge toxicities among patients treated with investigational or commercial lifileucel at Memorial Sloan Kettering Cancer Center between October 2020 and October 2024. Investigators assessed new TRAEs, blood product administration, and readmissions from hospital discharge until the initiation of subsequent systemic therapy or death.¹

The findings may help guide postdischarge monitoring for patients receiving TIL therapy, an area in which treatment-related risks remain less well characterized than inpatient toxicities.

Postdischarge Safety Findings

Over a median follow-up of 5 months after discharge (IQR, 3-18), 2 patients (3.9%) developed new grade 3 TRAEs. These events included grade 3 neutropenia occurring 73 days after discharge and grade 3 hypoxia occurring 104 days after discharge.¹

Treatment-related readmissions were also uncommon. Four patients (7.8%) were readmitted because of TRAEs, including cytopenias, dyspnea, and syncope. The median time to readmission was 49 days after discharge (IQR, 22-81).¹

Although severe toxicities and treatment-related readmissions occurred infrequently, outpatient transfusions remained an important component of postdischarge care. Twelve patients (24%) received outpatient transfusions, with a median of 2 units of packed red blood cells (IQR, 1-4) and 4 units of platelets (IQR, 2-4).¹

Together, these findings suggest that patients may continue to require supportive care after leaving the hospital, even when new severe toxicities are uncommon.

Implications for TIL Therapy Monitoring

Lifileucel is an autologous TIL therapy that uses a patient's own tumor-derived immune cells to target cancer. The treatment involves collecting tumor tissue, isolating and expanding tumor-infiltrating lymphocytes, and reinfusing these cells following lymphodepleting chemotherapy. Interleukin-2 (IL-2) is administered after infusion to support the activity of the transferred cells.

The US Food and Drug Administration granted accelerated approval to lifileucel in February 2024 for adults with unresectable or metastatic melanoma previously treated with a programmed cell death protein 1 (PD-1)–blocking antibody and, when applicable, a BRAF inhibitor with or without an MEK inhibitor.²

Although TIL therapy offers an additional treatment option for patients with advanced melanoma, its administration and associated supportive care require substantial coordination. Toxicities related to lymphodepleting chemotherapy and IL-2 are well recognized, but less is known about adverse events that emerge after discharge.

The study authors concluded that the low rates of new severe toxicities and treatment-related readmissions support individualized follow-up approaches for patients receiving lifileucel, rather than automatically applying monitoring schedules used for other cellular therapies.¹

The investigators also highlighted the need for specific postdischarge guidelines for TIL therapy. Further research to identify patients at increased risk of delayed toxicities could help clinicians tailor follow-up frequency and supportive care while maintaining patient safety.

REFERENCES

1. Andreoli M, Kalvin HL, Cathcart ER, et al. Outpatient treatment-related toxicity after hospital discharge among patients receiving lifileucel for advanced melanoma. JCO Oncol Pract. 0, OP-26-00407. doi:10.1200/OP-26-00407

2. FDA approves first cellular therapy to treat patients with unresectable or metastatic melanoma. News release. FDA. February 16, 2024. Accessed October 21, 2026. http://tinyurl.com/5n7cuszk