1区 · 医学
Article
作者: Spira, Alexander I ; Likes, Molly ; Kemp, Lindsey ; Puccia, Christopher ; Schenk, Desiree ; Kounlavouth, Sonia ; Egorova, Milana ; Li, Yaojun John ; Rappaport, Amy R ; Johnson, Benny ; Bae, Kyounghwa ; Sousa, Leiliane ; Hecht, J Randolph ; Yang, Aaron ; Carbone, David P ; Shen, Annie ; Palmer, Christine D ; Veres, Robert L ; Goldman, Jonathan W ; Jooss, Karin ; Ferguson, Andrew R ; Shergill, Ardaman ; Lane, Monica ; Kyi, Chrisann ; Henick, Brian S ; Zhou, Rita ; Mahipal, Amit ; Liao, Chih-Yi ; Acrebuche, Lindsey ; Espinosa, J Aaron ; Johnson, Melissa L ; Allen, Andrew ; Davis, Matthew J ; Scallan, Ciaran D ; Kraemer Tardif, Lauren D ; Boucher, Gregory R ; Jaroslavsky, Jason R ; Hart, Meghan G
Therapeutic vaccines that elicit cytotoxic T cell responses targeting tumor-specific neoantigens hold promise for providing long-term clinical benefit to patients with cancer. Here we evaluated safety and tolerability of a therapeutic vaccine encoding 20 shared neoantigens derived from selected common oncogenic driver mutations as primary endpoints in an ongoing phase 1/2 study in patients with advanced/metastatic solid tumors. Secondary endpoints included immunogenicity, overall response rate, progression-free survival and overall survival. Eligible patients were selected if their tumors expressed one of the human leukocyte antigen-matched tumor mutations included in the vaccine, with the majority of patients (18/19) harboring a mutation in KRAS. The vaccine regimen, consisting of a chimp adenovirus (ChAd68) and self-amplifying mRNA (samRNA) in combination with the immune checkpoint inhibitors ipilimumab and nivolumab, was shown to be well tolerated, with observed treatment-related adverse events consistent with acute inflammation expected with viral vector-based vaccines and immune checkpoint blockade, the majority grade 1/2. Two patients experienced grade 3/4 serious treatment-related adverse events that were also dose-limiting toxicities. The overall response rate was 0%, and median progression-free survival and overall survival were 1.9 months and 7.9 months, respectively. T cell responses were biased toward human leukocyte antigen-matched TP53 neoantigens encoded in the vaccine relative to KRAS neoantigens expressed by the patients' tumors, indicating a previously unknown hierarchy of neoantigen immunodominance that may impact the therapeutic efficacy of multiepitope shared neoantigen vaccines. These data led to the development of an optimized vaccine exclusively targeting KRAS-derived neoantigens that is being evaluated in a subset of patients in phase 2 of the clinical study. ClinicalTrials.gov registration: NCT03953235 .