(NCT05188508) Another phase II clinical trial of olaparib in IDH-mutant subjects having recurrent high-grade type gliomas is completed, and this study elucidated the treatment efficacy of olaparib in IDH-mutant subjects with recurrent high-grade type gliomas based on their 6-month growth-free survival rate. The gene discussed is IDH2; the disease is central nervous system cancer.