Autologous T cell therapy for PRAME+ advanced solid tumors in HLA-A*02+ patients: a phase 1 trial
Martin Wermke, Dejka M Araurjo, Manik Chatterjee, Apostolia M. Tsimberidou, Tobias A.W. Holderried, Amir A. Jazaeri, Ran Reshef, Carsten Bokemeyer, Winfried Alsdorf, Katrin Wetzko, Peter Brossart, Katrin Aslan, Linus Backert, Sebastian Bunk, Jens Fritsche, Swapna Gulde, Silvana Hengler, Norbert Hilf, M. Belal Hossain, Jens Hukelmann, Mamta Kalra, Delfi Krishna, M. Alper Kursunel, Dominik Maurer, Andrea Mayer-Mokler, Regina Mendrzyk, Ali Mohamed, Karine Pozo, Arun Satelli, M Letizia, Heiko Schuster, Oliver Schoor, Claudia Wagner, Hans‐Georg Rammensee, Carsten Reinhardt, Harpreet Singh‐Jasuja, Steffen Walter, Toni Weinschenk, Jason J. Luke, Cedrik M. Britten
Abstract
In contrast to chimeric antigen receptor T cells, T cell receptor (TCR)-engineered T cells can target intracellular tumor-associated antigens crucial for treating solid tumors. However, most trials published so far show limited clinical activity. Here we report interim data from a first-in-human, multicenter, open-label, 3 + 3 dose-escalation/de-escalation phase 1 trial studying IMA203, an autologous preferentially expressed antigen in melanoma (PRAME)-directed TCR T cell therapy in HLA-A*02+ patients with PRAME+ recurrent and/or refractory solid tumors, including melanoma and sarcoma. Primary objectives include the evaluation of safety and tolerability and the determination of the maximum tolerated dose (MTD) and/or recommended dose for extension. Secondary objectives include the evaluation of IMA203 TCR-engineered T cell persistence in peripheral blood, tumor response as well as duration of response. A total of 27 patients were enrolled in the phase 1a dose escalation and 13 patients in the phase 1b dose extension. IMA203 T cells were safe, and the MTD was not reached. Of the 41 patients receiving treatment (that is, who started lymphodepletion), severe cytokine release syndrome was observed in 4.9% (2/41), and severe neurotoxicity did not occur. In the 40 patients treated with IMA203, an overall response rate consisting of patients with unconfirmed or confirmed response (u/cORR) of 52.5% (21/40) and a cORR of 28.9% (11/38) was observed with a median duration of response of 4.4 months (range, 2.4–23.0, 95% confidence interval: 2.6–not reached) across multiple indications. Rapid T cell engraftment and long-term persistence of IMA203 T cells were observed. IMA203 T cells trafficked to all organs, and confirmed responses were more frequent in patients with higher dose. T cell exhaustion was not observed in the periphery; deep responses were enriched at higher PRAME expression; and higher T cell infiltration resulted in longer progression-free survival. Overall, IMA203 showed promising anti-tumor activity in multiple solid tumors, including refractory melanoma. ClinicalTrials.gov identifier: NCT03686124 . In a non-prespecified interim analysis of a phase 1 trial, autologous PRAME-directed TCR T cell therapy was safe and elicited durable responses in patients with recurrent and/or treatment-refractory PRAME+ advanced solid tumors, including melanoma and synovial sarcoma.