Neoantigen-specific TCRs (neoTCR) were identified from patient CD8+ T cells and selected following insertion into healthy donor T cells; up to three neoTCRs were engineered into patient T cells using CRISPR/Cas9 to simultaneously silence endogenous TCRs. 16 patients with relapsed/refractory metastatic solid tumors were treated in a phase 1 trial. NeoTCR cell expansion peaked after ~2 days in blood and was supported by preconditioning chemotherapy, IL-2 supplementation, higher cell dose, or optimized manufacturing. Treatment was well tolerated; 5 patients demonstrated stable disease, and “bar-coding” demonstrated trafficking to tumors.
Contributed by Alex Najibi
ABSTRACT: The T cell receptor (TCR) provides the fine specificity of T cells to recognize mutations in cancer cells 1-3. We developed a clinical-grade approach based on CRISPR/Cas9 non-viral precision genome editing to simultaneously knock-out the two endogenous TCR genes, TCR_ (TRAC) and TCR_ (TRBC), and insert in the TRAC locus the two chains of a neoantigen-specific TCR (neoTCR), isolated from the patient's own circulating T cells using a personalized library of soluble predicted neoantigen-HLA capture reagents. Sixteen patients with refractory solid cancers received up to three distinct neoTCR-transgenic cell products, each expressing a patient-specific neoTCR, in a cell dose-escalation, first-in-human phase 1 clinical trial (NCT03970382). One patient had grade 1 cytokine release syndrome, and one grade 3 encephalitis. All had the expected side effects from the lymphodepleting chemotherapy. Five patients had stable disease, and the other 11 had disease progression as best response on therapy. NeoTCR-transgenic T cells were detected in tumour biopsies post-infusion at frequencies higher than the native TCRs pre-infusion. This study demonstrates the feasibility of isolating and cloning multiple TCRs recognizing mutational neoantigens, the simultaneous knock-out of the endogenous TCR and knock-in of the neoTCRs using single-step, non-viral precision genome editing, the manufacturing of neoTCR engineered T cells at clinical grade, the safety of infusing up to three gene edited neoTCR T cell products, and the ability of the transgenic T cells to traffic to the patients' tumours.
Author Info: (1) PACT Pharma, South San Francisco, CA, USA. sfoy@pactpharma.com. (2) PACT Pharma, South San Francisco, CA, USA. (3) Department of Neurology and Chao Family Comprehensive Cancer
Author Info: (1) PACT Pharma, South San Francisco, CA, USA. sfoy@pactpharma.com. (2) PACT Pharma, South San Francisco, CA, USA. (3) Department of Neurology and Chao Family Comprehensive Cancer Center, University of California, Irvine, CA, USA. (4) PACT Pharma, South San Francisco, CA, USA. (5) PACT Pharma, South San Francisco, CA, USA. (6) PACT Pharma, South San Francisco, CA, USA. (7) PACT Pharma, South San Francisco, CA, USA. (8) PACT Pharma, South San Francisco, CA, USA. (9) PACT Pharma, South San Francisco, CA, USA. (10) PACT Pharma, South San Francisco, CA, USA. (11) PACT Pharma, South San Francisco, CA, USA. (12) PACT Pharma, South San Francisco, CA, USA. (13) PACT Pharma, South San Francisco, CA, USA. (14) PACT Pharma, South San Francisco, CA, USA. (15) PACT Pharma, South San Francisco, CA, USA. (16) PACT Pharma, South San Francisco, CA, USA. (17) PACT Pharma, South San Francisco, CA, USA. (18) PACT Pharma, South San Francisco, CA, USA. (19) PACT Pharma, South San Francisco, CA, USA. (20) PACT Pharma, South San Francisco, CA, USA. (21) PACT Pharma, South San Francisco, CA, USA. (22) PACT Pharma, South San Francisco, CA, USA. (23) PACT Pharma, South San Francisco, CA, USA. (24) PACT Pharma, South San Francisco, CA, USA. (25) PACT Pharma, South San Francisco, CA, USA. (26) Institute for Systems Biology, Seattle, WA, USA. (27) Institute for Systems Biology, Seattle, WA, USA. (28) PACT Pharma, South San Francisco, CA, USA. (29) Department of Medicine, Division of Hematology-Oncology, University of California, Los Angeles (UCLA), Los Angeles, CA, USA. (30) PACT Pharma, South San Francisco, CA, USA. (31) PACT Pharma, South San Francisco, CA, USA. (32) PACT Pharma, South San Francisco, CA, USA. (33) PACT Pharma, South San Francisco, CA, USA. (34) PACT Pharma, South San Francisco, CA, USA. (35) PACT Pharma, South San Francisco, CA, USA. (36) PACT Pharma, South San Francisco, CA, USA. (37) PACT Pharma, South San Francisco, CA, USA. (38) PACT Pharma, South San Francisco, CA, USA. (39) PACT Pharma, South San Francisco, CA, USA. (40) PACT Pharma, South San Francisco, CA, USA. (41) PACT Pharma, South San Francisco, CA, USA. (42) Division of Hematology/Oncology, Department of Medicine, University of California, San Francisco, CA, USA. (43) Department of Medicine, Division of Hematology-Oncology, University of California, Los Angeles (UCLA), Los Angeles, CA, USA. Jonsson Comprehensive Cancer Center at the University of California Los Angeles, Los Angeles, CA, USA. (44) Division of Hematology/Oncology, Department of Internal Medicine, University of California Davis Comprehensive Cancer Center, Sacramento, CA, USA. (45) Department of Medical Oncology and Therapeutics Research, City of Hope National Medical Center, Duarte, CA, USA. (46) Department of Medicine and Robert H. Lurie Cancer Center, Northwestern University, Evanston, IL, USA. (47) Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA. (48) Thoracic Oncology Service, Division of Solid Tumor Oncology, Department of Medicine, Memorial Sloan Kettering Cancer Center, Weill Cornell Medical College, New York, NY, USA. (49) Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA. (50) Institute for Systems Biology, Seattle, WA, USA. (51) PACT Pharma, South San Francisco, CA, USA. (52) Department of Medicine, Division of Hematology-Oncology, University of California, Los Angeles (UCLA), Los Angeles, CA, USA. ARibas@mednet.ucla.edu. Jonsson Comprehensive Cancer Center at the University of California Los Angeles, Los Angeles, CA, USA. ARibas@mednet.ucla.edu. (53) PACT Pharma, South San Francisco, CA, USA. (54) PACT Pharma, South San Francisco, CA, USA. smandl@pactpharma.com.
