Identifying Factors That Limit Access to Tumor-Infiltrating Lymphocytes (TILs) for Advanced Melanoma at a High Volume Academic Center

Tumor-infiltrating lymphocyte (TIL) therapy is a promising but logistically complex treatment for advanced melanoma. Successful delivery requires tight coordination among medical oncology, surgical teams, cell therapy programs, and industry partners. We evaluated the feasibility and time intervals of our TIL start-up process, focusing on key milestones from referral to infusion. • Outline the steps necessary for TIL referral and treatment • Review causes that led to no infusion of TIL therapy • Identify areas for improvement in order to expedite TIL infusion We conducted a retrospective review of all patients referred for TIL therapy over a 12—month interval (May 1, 2024, and May 1, 2025). We collected demographic data and tracked time intervals between referral, consultation, insurance authorization, tumor harvest, and infusion. Twenty-one patients (57.1% female; mean age 60.3 years range 27–78) were referred, all with advanced melanoma and a median of 2 prior systemic therapies. Over half (52.4%) had liver and/or brain metastases and 19% only had brain metastases. Median time from diagnosis of primary melanoma to TIL referral was 38.7 months. Median time from referral to cell therapy consultation was 10 days (range 1–34), and to surgical consultation was 12.5 days (range 0–38). Insurance authorization (required for pre-lymphocyte harvest) took a median of 25 days (range 8–68) following cell therapy consultation. At data cutoff, 10 of 21 patients (47.6%) proceeded to tumor harvest. See Figure 1. Two TIL products were out of specification: one required re-harvest and one was treated using the out-of-specification product (expanded access protocol). Median time from referral to harvest was 39 days (range 22–99). At data cutoff, 5 patients (23.8%) had undergone lymphodepletion and TIL infusion, with a median interval of 106 days (range 66–152) from referral. Among the remaining 16 patients, 5 underwent harvest but not infusion due to progression (n=3), remission with bridging therapy (n=1), or pending admission (n=1). Eleven patients did not undergo harvest due to patient declination (n=3), insufficient disease for harvest (n=5), or rapid progression (n=3). Access to TIL therapy for advanced melanoma requires complex coordination of care and the multistep timeline appears to be a barrier to treatment. Only a subset of referred patients ultimately received TIL infusion, largely due to clinical deterioration or insufficient harvest sites. Timely referral, early insurance initiation, and streamlined multidisciplinary workflows are critical to improving patient throughput in TIL therapy programs.