Calithera Biosciences has commenced a Phase I/II clinical trial of its telaglenastat (CB-839) in combination with Pfizer’s palbociclib (Ibrance) for the treatment of cancer.

Telaglenastat is a glutaminase inhibitor, while palbociclib inhibits cyclin-dependent kinase (CDK) 4/6.

Genetic alterations, including KRAS mutations, are known to lead to increased glutamine metabolism in cancer cells.

Preclinical studies in KRAS-mutated cancer models demonstrated that telaglenastat has synergistic anti-tumour effects when combined with CDK4/6 inhibitors. This synergistic approach was observed to boost cell cycle arrest and block cancer cell proliferation.

The open-label Phase I/II trial will assess the safety and anti-tumour activity of the combination in locally advanced/metastatic KRAS-mutated colorectal cancer (CRC) patients.

The study will also involve participants with KRAS-mutated non-small cell lung cancer (NSCLC). Patients who are refractory or intolerant to standard therapies will be enrolled.

The first subject in the trial has already been treated with a combination of telaglenastat and palbociclib.