The overexpression of GLS provides a rationale for glutaminase inhibition as part of anticancer therapy. 

Telaglenastat is an investigational, first-in-class, selective oral glutaminase inhibitor that blocks glutamine utilization and downstream pathways.  It induces autophagy and has antitumor activity.

Clinical trials have been conducted for several tumors, including clear cell RCC, both as monotherapy and in combination with approved therapeutic agents such as everolimus, cabozantinib, and nivolumab. 

Early results of Phase 1/2 clinical trials look promising, especially for telaglenastat plus cabozantinib, and all combinations seem to be well tolerated.

Reference: Brown JE. Glutaminase Inhibitors—Do They Have a Role in the Treatment of Metastatic Clear-Cell Renal Cell Carcinoma? JAMA Oncol. Published online September 01, 2022.