New severe treatment-related adverse effects after discharge from lifileucel therapy were uncommon and emerged across several months.
Among patients with advanced melanoma who were discharged after receiving lifileucel (Amtagvi), new severe treatment-related adverse effects (TRAEs) and hospital readmissions due to TRAEs were infrequent, according to findings from a retrospective analysis published in The Journal of Clinical Oncology, Oncology Practice.1
At a median follow-up of 5 months after discharge (interquartile range [IQR], 3-18), 3.9% of patients in the overall population (n = 51) experienced a new grade 3 TRAE. Of these 2 patients, 1 experienced grade 3 acute neutropenia that arose 73 days after discharge, with the other experiencing grade 3 hypoxia that arose at 104 days. TRAEs led to hospital readmission in 7.8% of patients, with a median time from discharge to readmission of 49 days (IQR, 22-81). Twenty-four percent of patients required transfusions in the outpatient setting. These patients received a median of 2 units of packed red blood cells (IQR, 1-4) and 4 units of platelets (IQR, 2-4).
Investigators concluded that patients receiving tumor-infiltrating lymphocyte (TIL) therapy may be candidates for follow-up tailored to the individual after discharge, rather than the more intensive monitoring used with other cellular therapies.
“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,” Mia Andreoli, MD, and coauthors wrote in the publication.
Anderoli is a resident physician of Internal Medicine at Weill Cornell Medicine in New York, New York.
For the analysis, investigators reviewed the records of every patient with advanced melanoma who was discharged from Memorial Sloan Kettering Cancer Center between October 2020 and October 2024 after receiving lifileucel. Patients were treated either on an investigational protocol (LN-144) or with commercial lifileucel product.
Patients were followed from discharge until they began another systemic therapy or died. Investigators recorded how often new TRAEs occurred and when, along with blood product use and readmissions. Grading followed the National Cancer Institute’s Common Terminology Criteria for Adverse Events version 5.0.
Patients in the analysis had a median age of 61 years (IQR, 41-66). By melanoma subtype, 37% of patients had cutaneous disease, 18% had uveal disease, 16% had acral disease, 16% had mucosal disease, and 14% had an unknown primary site. Among 49 evaluable patients, 24% harbored a BRAF mutation.
Standard lymphodepleting chemotherapy (LDC) was given to 78% of patients, consisted of 2 days of cyclophosphamide at 60 mg/kg once daily plus 4 days of fludarabine at 25 mg/m² once daily. A reduced-intensity LDC regimen was used in 20% of patients: 3 days of cyclophosphamide at 750 mg/m² once daily plus 4 days of fludarabine at 30 mg/m² once daily.
In total, 44 patients (88%) underwent LDC in the inpatient setting. One patient who began LDC as an outpatient was moved to inpatient care after a syncopal event. Every patient received between 1 and 6 doses of interleukin-2 (median, 4; IQR, 4-6). Hospital stays lasted a median of 19 days (IQR, 16-23).
A complete response to lifileucel occurred in 8% of patients and a partial response in 24%. Another 35% had stable disease, and 33% had progressive disease.
Lifileucel was given under an investigational protocol in 84% of patients. This group included 7 patients with active brain metastases who were treated in a phase 1 trial (NCT05640193) that set a higher platelet goal, requiring counts above 50,000/μL.1,2
Twenty-two percent of patients were readmitted to the hospital for any reason. Seven of these readmissions stemmed from melanoma progression and 4 from TRAEs.1 Across all readmissions, the median interval was 85 days (IQR, 39-129) from lifileucel infusion and 69 days (IQR, 19-98) from the initial discharge.
For TRAE-related readmissions, the median interval from infusion was 60 days (IQR, 34-94), 49 days (IQR, 22-81) after initial discharge, and the median stay was 3.5 days (IQR, 3-60. Both patients with new grade 3 TRAEs required readmission, in addition to 1 patient with persistent refractory pancytopenia and 1 with repeated episodes of syncope.
Investigators suggested that close monitoring in the early postdischarge period would be unlikely to substantially lower risk for these patients. They also called for dedicated postdischarge guidance for patients treated with TIL therapy. They noted that a lighter follow-up schedule may be especially reasonable for patients whose blood counts have recovered by the time of discharge. The investigators also acknowledged that the data came from a single center and were collected retrospectively.
