20 March 2024

A Phase I Study of the Oral Dual-Acting Pan-PI3K/mTOR Inhibitor Bimiralisib in Patients with Advanced Solid Tumors

The phosphatidylinositol 3-kinase (PI3K)/Akt (protein kinase B)/mammalian target of the rapamycin (mTOR) signaling pathway is important in regulating cell proliferation, growth, metabolism, and motility in response to environmental and growth signals. Inhibition of the PI3K/Akt/mTOR pathway by specific targeted inhibitors has been shown to lead to regression in human tumors in the preclinical setting. Clinically, several drugs targeting this pathway are in development. However, some of them have been subsequently withdrawn due to dose-related toxicity issues. Bimiralisib is an oral-balanced dual-acting PI3K/mTOR inhibitor. The aim of our study was to assess safety with different schedules of administration of bimiralisib. Results showed a good safety profile for the drug when administered using intermittent schedules, which may extend the drug exposure of patients and potentially increase the chance to see antitumor efficacy. The improved safety profile of the drug when given on an intermittent schedule also supports future potential combination with other targeted therapies.