A Phase 1 Study of the Safety, Pharmacokinetics, and Pharmacodynamics of Escalating Oral Doses of the Glutaminase Inhibitor CB-839 in Patients With Advanced and/or Treatment-Refractory Hematological Malignancies

Many tumor cells, in contrast to normal cells, have been shown to require the amino acid glutamine to produce energy for growth and survival. To exploit the dependence of tumors on glutamine, CB-839, a potent and selective inhibitor of the first enzyme in glutamine utilization, glutaminase, will be tested in this Phase 1 study in patients with advanced hematologic malignancies.

This study is an open-label Phase 1 evaluation of CB-839 in subjects with hematological tumors. Patients will receive CB-839 capsules orally two or three times daily. The study will be conducted in 2 parts. Part 1 is a dose escalation study to identify the recommended Phase 2 dose and will enroll patients with advanced and/or treatment-refractory Non-Hodgkin's Lymphoma (NHL), Multiple Myeloma (MM), or Waldenström's macroglobulinemia (WM)

In Part 2, all patients will receive the recommended Phase 2 dose. This part will enroll patients with advanced and/or treatment-refractory Non-Hodgkin's Lymphoma (NHL), Multiple Myeloma (MM), or Waldenström's macroglobulinemia (WM). All patients will be assessed for safety, pharmacokinetics (plasma concentration of drug), pharmacodynamics (inhibition of glutaminase), biomarkers (biochemical markers that may predict responsiveness in later studies), and tumor response.

As an extension of Part 2, a cohort of patients with relapsed and refractory MM will be enrolled to receive low dose dexamethasone and CB-839. A second cohort of patients with relapsed or refractory disease following at least 2 prior treatment regimens will be enrolled to receive CB-839 in combination with standard-dose pomalidomide and low-dose dexamethasone to further evaluate this triple combination.