Abstract A05: Expansion of tumor-infiltrating lymphocytes (TIL) using Iovance's Gen 2 process from advanced bladder cancer for adoptive immunotherapy

Background: Patients with advanced bladder cancer have limited therapeutic options, apart from cisplatin-based chemotherapy and use of immune checkpoint inhibitors (ICI). Median survival for patients with metastatic disease is 15 to 18 months. Hence there is a need for more effective therapies. Adoptive cell therapy using tumor-infiltrating lymphocytes (TIL) has demonstrated durable and complete responses with long-term survival of > 10 years in patients with metastatic melanoma. Previous attempts to generate TIL from bladder cancer showed some success; however, the process required an extended manufacturing time (35–50+ days). Iovance has developed a second-generation GMP manufacturing process (Gen 2) with a significantly reduced time to expand functional TIL from melanoma, cervical, and head and neck tumors. The goal of this study was to determine the feasibility of generating TIL from patient-derived bladder cancer tumor specimens using the 22-day Iovance Gen 2 manufacturing process. Methods: The TIL manufacturing process for the resected bladder tumor samples includes a pre-Rapid Expansion Protocol (pre-REP) and Rapid Expansion Protocol (REP) over 22 days. Pre-REP (1/10th scale) and REP (1/100th scale) was performed to align with the Iovance Gen 2 manufacturing process. During the pre-REP 1- to 3-mm size tumor fragments are placed in media containing IL-2 for 11 days. To further stimulate TIL growth, TIL are expanded using REP that includes irradiated PBMC feeders, IL-2, and anti-CD3 for 11 days. Release testing parameters (total viable cells, % viability, TIL phenotype) were tested on the harvested final product. TIL purity, differentiation, memory, activation, and exhaustion status were extensively characterized using multicolor flow cytometry. TIL functionality was determined by measuring IFNγ and Granzyme B release after restimulation. Results: Four bladder tumor samples were obtained from Roswell Park Comprehensive Cancer Center (RPCCC). Total viable count of REP TIL harvested on Day 22 was 18.4 +/- 8.9 × 109 (numbers adjusted to full scale), with 92.7 +/- 2.5% viability at harvest. The phenotype of harvested TIL were 92.4 +/- 4.8% CD3+/CD45+ cells, and non-T cell population including B cells and NK cells were Conclusions: All four bladder carcinoma-derived TIL have demonstrated growth, phenotype, and function comparable to that for other tumor types (i.e., melanoma, cervical, HNSCC). TIL generation from bladder cancer samples is feasible and allows for the application of Iovance9s Gen 2 manufacturing process for an autologous cellular infusion product to treat bladder cancer patients. An early-phase trial testing autologous TIL therapy in transitional cell cancer of the urothelium is being planned. Citation Format: Qiang J. LI, Khurshid Guru, Amit Lugade, Elizabeth Brese, Kunle Odunsi, Anand Veerapathran, Kenneth Onimus, Adrian Wells, Cecile Chartier, Arvind Natarajan, Maria Fardis, Gurkamal Chatta. Expansion of tumor-infiltrating lymphocytes (TIL) using Iovance9s Gen 2 process from advanced bladder cancer for adoptive immunotherapy [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2019 May 18-21; Denver, CO. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(15_Suppl):Abstract nr A05.