Development of the combined immunotherapy; immune checkpoint inhibitor and cancer vaccine

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H04410
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Surgical dentistry
• Research Institution: Tsurumi University (2019); Osaka University (2017-2018)
• Principal Investigator: OKAMOTO MASATO 鶴見大学, 歯学部, 臨床教授 (10243718)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 癌ワクチン / 免疫チェックポイント阻害剤 / 樹状細胞 / 複合免疫療法 / 口腔癌

Outline of Final Research Achievements

We investigated the effect of the combined immunotherapy with the cancer vaccine using dendritic cells (DC) and the immune checkpoint inhibitor. In in vitro experiment, induction of cytotoxic T lymphocytes (CTLs) against WT1, which was reported to be expressed in oral squamous cell carcinoma cells, was enhanced by the combined use of anti-PD-1 antibody. In in vivo study using syngeneic tumor-bearing mice, stronger anti-tumor effect was observed by the treatment with WT1 pulsed DC vaccine and anti-PD-1 antibody as compared with DC vaccine alone or anti-PD-1 antibody alone. We conducted a pilot study of the combination therapy with anti-PD-1 antibody + cancer antigen pulsed DC vaccine. Up to now, 6 patients with unresectable oral cancer have been treated with the same method and are under observation. In all cases, induction of CTL specific for at least one cancer antigen used was confirmed. We plan to continue expanding the number of cases.

Free Research Field

癌免疫療法

Academic Significance and Societal Importance of the Research Achievements

オプジーボやキィトルーダ等の免疫チェックポイント阻害剤による癌治療効果が明らかになり癌に対する免疫療法が注目されている。しかしな、免疫チェックポイント阻害剤の治療効果は15～25％程度であり決して満足できるものではない。さらなる治療効果向上の為に癌ワクチンとの併用が期待されている。本研究結果にて、樹状細胞ワクチンと免疫チェックポイント阻害剤の併用が非常に効果的である可能性が強く示唆され、より有効な癌治療法の開発に寄与すると考えられる。