Results from a Phase 0/1 clinical trial of the breast cancer drug ribociclib (Kisqali®; Novartis), a kinase inhibitor, plus everolimus (Afinitor®; Novartis), a derivative of sirolimus and an inhibitor of tor serine-threonine kinases, in patients with high-grade glioma (HGG) demonstrate that ribociclib achieved pharmacologically-relevant concentrations in gadolinium (Gd)-non-enhancing tumor, consistent with the observed tumor pharmacodynamics (PD) effects. In contrast, everolimus demonstrated minimal penetration in the (Gd)-non-enhancing compartment of the tumor.

In high-grade glioma (HGG), the RB-CDK4/6 and mTOR signaling pathways are deregulated and mTOR activation is a potential mechanism of resistance to CDK4/6 inhibition.

The purpose of the study, conducted by the Ivy Brain Tumor Center at Barrow Neurological Institute, the largest early-phase drug development program for brain cancer in the world, was to determine the combined effect of RB-CDK4/6 and mTOR inhibitors on recurrent HGGs by evaluating the tumor pharmacokinetics (PK) and tumor pharmacodynamics (PD). The study was funded by the Ben and Catherine Ivy Foundation and the individual donors of the Barrow Neurological Foundation.

The results were published in the Journal of Neuro-Oncology and will also be presented at the European Association for Neuro-Oncology (EANO) Meeting on September 26, 2021, by Nader Sanai, MD, director of the Ivy Brain Tumor Center and director of neurosurgical oncology at Barrow Neurological Institute.

References:

https://www.oncozine.com/results-of-a-phase-0-1-trial-of-ribociclib-everolimus-in-recurrent-high-grade-glioma/