Phase 1 study of GT101 as an autologous tumor infiltrating lymphocyte (TIL) therapy in advanced solid tumors.
Authors: Haifeng Qin, Yongsheng Wang, Yuyao Yi, Fang Gao, Dongling Zou, Yongsheng Li, Xiubao Ren, Dongmei Ji, Jian Zhang, Shasha Wang, Zhen Zeng, Jing Yu, Liqing Ma, Yishan Liu, Lili Lu, Derun Shen, Xue Zhai, Pin Wang, Yarong Liu
Journal: Journal of Clinical Oncology (2024)

2548 Background: Adoptive cell therapy utilizing autologous TIL has demonstrated efficacy and durable long-term responses in patients with certain advanced solid tumors progressed after conventional therapies. We present data from 14 patients enrolled in the study of GT101, a Phase 1, open-label, single-arm, multicenter trial (NCT05430373) of autologous TIL therapy, aiming to investigate the safety profile, efficiency trend and the duration of response. Methods: The trial was designed with the primary endpoint on evaluating DLT and characterizing the safety profile of GT101 in solid tumor patients measured by the incidence of Grade ≥ 3 treatment-emergent adverse events (TEAEs). The secondary endpoints were to assess efficacy parameters including overall response rate (ORR), disease control rate (DCR), progression-free survival (PFS), duration of response (DOR), and overall survival (OS) according to RECIST v1.1. Results: As of November 10, 2023, a cohort of 14 patients received treatment with a median age of 46.9 and a median of 2.6 lines of prior therapies. Following a standard FC-based lymphodepletion, patients underwent GT101 infusion at doses ≥ 5x10 9 cells with median dose of 3.7x10 10 cells, followed by high-dose IL-2 administration. Most of observed Grade ≥ 3 AEs were related to the FC conditioning regimen and IL-2, including decreased lymphocyte count, decreased white blood cell count, decreased neutrophil count, anemia, pyrexia and decreased platelet count. The majority of these AEs were recovered within 14 days, while a few were downgraded to ≤ Grade 2 within 4 weeks. Among 14 enrolled patients across various indications (small-cell-lung cancer, melanoma, cervical cancer), the ORR was 35.7%. Specifically, 4 pts (28.6%) had a confirmed partial response (PR), 1 pt (7.1 %) achieved complete response (CR), and 8 pts (57.1 %) had stable disease (SD) as their best response. One pt had unconfirmed disease progression (PD). Notably, among 11/14 patients with cervical cancer, the ORR was 45.5% (5/11) with 4 pts (36.4%) achieving PR and 1 pt (9.1 %) achieving CR. Disease control was observed in 10/11 pts (90.9%), and the median PFS was 4.2 months for this cohort. The CR patient underwent a long-term follow-up and the duration of CR and PFS (estimated by Kaplan-Meier) was 24 weeks and 36 weeks, respectively. Post GT101 infusion, T cell expanded robustly in the peripheral blood of all patients with median Tmax 6.83 days and average 15.9 days. Conclusions: In the GT101 Phase 1 study, no treatment-related SAEs and DLT were observed. In patients with heavily pretreated advanced or metastatic solid tumors, GT101 exhibited a manageable safety profile under the treatment protocol of lymphodepletion and high-dose IL-2 and a favorable clinical profile, particularly in cervical cancer, with an encouraging ORR and sustained response duration. Clinical trial information: NCT05430373 .