(1) Levin N (2) Kim SP (3) Marquardt CA (4) Vale NR (5) Yu Z (6) Sindiri S (7) Gartner JJ (8) Parkhurst M (9) Krishna S (10) Lowery FJ (11) Zacharakis N (12) Levy L (13) Prickett TD (14) Benzine T (15) Ray S (16) Masi RV (17) Gasmi B (18) Li Y (19) Islam R (20) Bera A (21) Goff SL (22) Robbins PF (23) Rosenberg SA

Journal for immunotherapy of cancer

Levin and Kim et al. developed a method for selective expansion of neoantigen-reactive CD4+ and CD8+ TILs with a broadened clonal repertoire, less exhaustion, and stem-like memory phenotypes by in vitro stimulation of bulk TILs with IL-2, IL-21, and APCs presenting selected p53 and RAS neoepitopes (“NeoExpand”). In contrast to TILs generated by conventional rapid expansion with OKT3, which reduced the frequencies of neoantigen-reactive T cells, NeoExpand TILs demonstrated improved antitumor efficacy in xenograft mouse models. Across 25 patients, NeoExpand facilitated the sensitive identification of rare and novel neoantigen-specific TCRs.

Contributed by Ute Burkhardt

BACKGROUND: Tumor-infiltrating lymphocytes (TILs) targeting neoantigens can effectively treat a selected set of metastatic solid cancers. However, harnessing TILs for cancer treatments remains challenging because neoantigen-reactive T cells are often rare and exhausted, and ex vivo expansion can further reduce their frequencies. This complicates the identification of neoantigen-reactive T-cell receptors (TCRs) and the development of TIL products with high reactivity for patient treatment. METHODS: We tested whether TILs could be in vitro stimulated against neoantigens to achieve selective expansion of neoantigen-reactive TILs. Given their prevalence, mutant p53 or RAS were studied as models of human neoantigens. An in vitro stimulation method, termed "NeoExpand", was developed to provide neoantigen-specific stimulation to TILs. 25 consecutive patient TILs from tumors harboring p53 or RAS mutations were subjected to NeoExpand. RESULTS: We show that neoantigenic stimulation achieved selective expansion of neoantigen-reactive TILs and broadened the neoantigen-reactive CD4(+) and CD8(+) TIL clonal repertoire. This allowed the effective isolation of novel neoantigen-reactive TCRs. Out of the 25 consecutive TIL samples, neoantigenic stimulation enabled the identification of 16 unique reactivities and 42 TCRs, while conventional TIL expansion identified 9 reactivities and 14 TCRs. Single-cell transcriptome analysis revealed that neoantigenic stimulation increased neoantigen-reactive TILs with stem-like memory phenotypes expressing IL-7R, CD62L, and KLF2. Furthermore, neoantigenic stimulation improved the in vivo antitumor efficacy of TILs relative to the conventional OKT3-induced rapid TIL expansion in p53-mutated or KRAS-mutated xenograft mouse models. CONCLUSIONS: Taken together, neoantigenic stimulation of TILs selectively expands neoantigen-reactive TILs by frequencies and by their clonal repertoire. NeoExpand led to improved phenotypes and functions of neoantigen-reactive TILs. Our data warrant its clinical evaluation. TRIAL REGISTRATION NUMBER: NCT00068003, NCT01174121, and NCT03412877.

Author Info: (1) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA sar@nih.gov peter.kim@nih.gov noam.levin@nih.gov. (2) Surgery Branch, Center for

Author Info: (1) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA sar@nih.gov peter.kim@nih.gov noam.levin@nih.gov. (2) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA sar@nih.gov peter.kim@nih.gov noam.levin@nih.gov. (3) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA. (4) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA. (5) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA. (6) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA. (7) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA. (8) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA. (9) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA. (10) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA. (11) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA. (12) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA. (13) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA. (14) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA. (15) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA. (16) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA. (17) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA. (18) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA. (19) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA. (20) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA. (21) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA. (22) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA. (23) Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA sar@nih.gov peter.kim@nih.gov noam.levin@nih.gov.

Citation: J Immunother Cancer 2024 May 30 12: Epub05/30/2024

Link to PUBMED: http://www.ncbi.nlm.nih.gov/pubmed/38816232

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