Tomoki Todo

Tomoki Todo is a professor at the Institute of Medical Science of The University of Tokyo, in the Division of Innovative Cancer Therapy and the Department of Surgical Neuro-Oncology. He developed G47 delta, a triple-mutated third-generation oncolytic herpes simplex virus type 1.

His investigator-initiated single-arm phase 2 trial gave G47 delta repeatedly into the tumour in 19 adults with residual or recurrent supratentorial glioblastoma after radiotherapy and temozolomide. One-year survival after starting treatment was 84.2 per cent, the prespecified endpoint was met and the trial stopped early. Imaging showed a characteristic pattern of the lesion enlarging while contrast enhancement cleared after each dose, so conventional response criteria recorded almost every patient as stable disease, and biopsies showed rising CD4-positive and CD8-positive lymphocyte infiltration with persistently low regulatory T cells. The result led to the approval of G47 delta in Japan, the first oncolytic virus product approved there.