Research press release


Nature Medicine

Therapeutic vaccine for renal cell cancer



Harpreet Singh-Jasujaたちは、癌細胞上にヒト白血球抗原HLA-Aを発現するRCC患者の組織試料を利用して、複数の特異的ペプチドを同定し、これを用いてワクチンを開発した。このワクチンIMA901は、この抗原を発現するRCC患者特異的に、免疫応答を誘発した。第1相試験では、IMA901ワクチンによって複数のT細胞免疫応答が誘発され、それに伴って、本来、免疫応答を抑制する働きをするはずの制御性T細胞数が少なくなっていた。また、IMA901ワクチン投与に先立ってシクロホスファミド(現在さまざまな癌の治療に利用されている薬)を単回投与した患者では、制御性T細胞数はさらに少なくなり、生存期間の延長に結びついた。このワクチンの効果を評価するには、もっと大きな集団で、さらに臨床試験を行う必要があるだろう。

Patients with advanced renal cell cancer (RCC), expressing a specific type of antigen, respond favorably to IMA901, which is the first therapeutic multipeptide vaccine for the disease, reports a study published in Nature Medicine this week.

Therapeutic vaccines differ from traditional preventative vaccines in that they are not administered prior to the disease, but as a means of delivering medication to those suffering from a disease. The development of therapeutic cancer vaccines has remained a challenge as there are gaps in our knowledge on several crucial issues, such as appropriate tumor antigens to target or biomarkers to predict patient’s response to therapy.

Using tissue samples from RCC patients expressing the human leukocyte antigen HLA-A on their cancer cells, Harpreet Singh-Jasuja and colleagues identified multiple specific peptides from which they developed a vaccine. The vaccine, IMA901, elicits an immune response specifically in RCC patients who express these antigens. In a phase 1 study, IMA901 vaccine induced multiple T cell immune responses that were associated with low numbers of T regulatory cells, which normally suppress immune responses. The authors also found that patients who were given a single-dose of cyclophosphamide-a drug presently used to treat various types of cancer-prior to IMA901 vaccination, had even fewer regulatory T cells, which resulted in prolonged survival of patients. Further clinical testing is needed to assess its benefit in a larger population.

doi: 10.1038/nm.2883


メールマガジンリストの「Nature 関連誌今週のハイライト」にチェックをいれていただきますと、毎週各ジャーナルからの最新の「注目のハイライト」をまとめて皆様にお届けいたします。