Lifileucel (Ln-144), A Cryopreserved Autologous Tumor Infiltrating Lymphocyte (Til) Therapy In Patients With Advanced (Unresectable Or Metastatic) Melanoma: Durable Duration Of Response At 28 Month Follow Up.

Background Beneficial treatment options are limited for advanced melanoma patients who progress after or do not respond to immune checkpoint inhibitors (ICI) and targeted therapies. Lifileucel is an adoptive cell therapy using tumor-infiltrating lymphocytes (TIL), that has shown efficacy in patients with advanced melanoma who have progressed on/after anti-PD-1therapy (Sarnaik et al., ASCO 2020). We present the 28-month (mos) follow-up data here. Methods C-144-01 (NCT02360579) is a global Phase 2 open-label, multicenter study of efficacy and safety of lifileucel in patients with unresectable metastatic melanoma who have progressed on anti-PD-1 therapy and BRAF/MEK inhibitors, if BRAF V600 mutant. We report on Cohort 2 (N = 66) patients who have received lifileucel. Tumors were resected at local institutions, processed in central GMP facilities for TIL production, manufactured, cryopreserved and shipped back to sites in a 22-day process. Therapy consisted of one week of nonmyeloablative lymphodepletion using cyclophosphamide (60 mg/kg on Day -7, -6) and fludarabine (25 mg/m2 on Day -5 through -1), a single infusion of lifileucel, and up to six doses of IL-2 doses (600,000 IU/kg/dose). Objective response rate (ORR) was based on RECIST v1.1 as assessed by investigators. Data cutoff was December 14, 2020. Results Baseline characteristics: 3.3 mean prior therapies (100% anti-PD-1; 80% anti-CTLA-4; 23% BRAF/MEK inhibitor), high baseline tumor burden (106 mm mean target lesion sum of diameters), 42% liver/brain lesions, 40.9% had LDH > ULN. Median time from last therapy to tumor harvest was 2.2 mos and 58% of the tumors resected were extra-nodal or non-skin/subcutaneous. ORR by Investigator was 36.4% (3 CR, 21 PR). One patient converted from a PR to CR at 24 mo after lifileucel therapy. Median time to first response was 1.4 mos (range: 1.3-5.6 mos). Median duration of response (mDOR) was still not reached at median follow-up of 28 mos (DOR range: 2.2-35.2 mos). No new safety risks have been identified for lifileucel during the long-term follow-up. Exploratory analyses of product-specific characteristics, including levels of phenotypic markers of T-cell lineage, memory subset, youth, activation/exhaustion, or trafficking did not demonstrate association with response. Conclusions Lifileucel treatment results in a 36.4% ORR and mDOR was not reached at 28 mo of median study follow up in heavily pretreated advanced melanoma patients with high baseline disease burden who progressed on multiple prior therapies, including anti-PD1 and BRAF/MEK inhibitors, if BRAF V600 mutant. Citation Format: Jason Alan Chesney, James M. Larkin, John M. Kirkwood, Jeffrey S. Weber, Nikhil I. Khushalani, Karl Lewis, Theresa M. Medina, Harriet M. Kluger, Sajeve S. Thomas, Evidio Domingo-Musibay, Judit Olah, Eric D. Whitman, Salvador Martin-Algarra, Philippa G. Corrie, Jose Lutzky, Omid Hamid, Wen Shi, Xiao Wu, Madan Jagasia, Friedrich Graf Finckenstein, Maria Fardis, Amod A. Sarnaik. Lifileucel (LN-144), a cryopreserved autologous tumor infiltrating lymphocyte (TIL) therapy in patients with advanced (unresectable or metastatic) melanoma: durable duration of response at 28 month follow up [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT008.