Resistance to checkpoint blockade therapy through inactivation of antigen presentation

• DOI: 10.1038/s41467-017-01062-w
• Publication Date: 2017-10-20T10:37:37Z
• Authors: Moshe Sade-Feldman; Yunxin J. Jiao; Jonathan H. Chen; Michael S. Rooney; Michal Barzily-Rokni; Jean-Pierre Eliane; Stacey L. Bjorgaard; Marc R. Hammond; Hans Vitzthum; Shauna M. Blackmon; Dennie T. Frederick; Mehlika Hazar-Ret...; Brandon A. Nadres; Emily E. Van Seve...; Sachet A. Shukla; Keren Yizhak; John P. Ray; Daniel Rosebrock; Dimitri Livitz; Viktor Adalsteinsson; Gad Getz; Lyn M. Duncan; Bo Li; Ryan B. Corcoran; Donald P. Lawrence; Anat Stemmer-Rach...; Genevieve M. Boland; Dan A. Landau; Keith T. Flaherty; Ryan J. Sullivan; Nir Hacohen
• Keywords: Mice, Knockout; Antigen Presentation; 0303 health sciences; Science; Q; Programmed Cell Death 1 Receptor; 610; Antibodies, Monoclonal; Loss of Heterozygosity; Neoplasms, Experimental; Article; 3. Good health; Mice, Inbred C57BL; 03 medical and health sciences; Drug Resistance, Neoplasm; Animals; Humans; Point Mutation; CTLA-4 Antigen; Female; Neoplasm Metastasis; beta 2-Microglobulin; Melanoma

AbstractTreatment with immune checkpoint blockade (CPB) therapies often leads to prolonged responses in patients with metastatic melanoma, but the common mechanisms of primary and acquired resistance to these agents remain incompletely characterized and have yet to be validated in large cohorts. By analyzing longitudinal tumor biopsies from 17 metastatic melanoma patients treated with CPB therapies, we observed point mutations, deletions or loss of heterozygosity (LOH) in beta-2-microglobulin (B2M), an essential component of MHC class I antigen presentation, in 29.4% of patients with progressing disease. In two independent cohorts of melanoma patients treated with anti-CTLA4 and anti-PD1, respectively, we find that B2M LOH is enriched threefold in non-responders (~30%) compared to responders (~10%) and associated with poorer overall survival. Loss of both copies of B2M is found only in non-responders. B2M loss is likely a common mechanism of resistance to therapies targeting CTLA4 or PD1.