Oncternal Therapeutics announced a clinical supply arrangement with Pharmacyclics through which Pharmacyclics supplies ibrutinib, a small molecule inhibitor of Bruton's tyrosine kinase (BTK), for a Phase 1b/2 clinical trial combining Oncternal's novel monoclonal antibody, cirmtuzumab, and ibrutinib in patients with mantle cell lymphoma (MCL) and chronic lymphocytic leukemia (CLL)/small lymphocytic leukemia (SLL).
"What we're looking to achieve in the treatment of B-cell malignancies is the production of deeper responses in patients — an outcome that is elusive with current standard of care therapies, despite their effectiveness," said James Breitmeyer, M.D., Ph.D., Oncternal's President and CEO. "We believe the complementary mechanisms of action of cirmtuzumab and ibrutinib could deliver this type of response and bring a new, urgently-needed treatment option to this patient population. We are very pleased that Pharmacyclics' support demonstrates a shared vision to improve the lives of patients with cancer."
Oncternal's CIRLL study (Cirmtuzumab and Ibrutinib targeting ROR1 for Lymphoma and Leukemia) is now underway, enrolling approximately 117 patients with MCL and CLL/SLL who have not received previous BTK inhibitor therapy. CIRLL is a randomized, open label, dose-finding study designed to evaluate the safety and efficacy of cirmtuzumab when given in combination with ibrutinib. The objective is to demonstrate that even more patients treated with the combination of cirmtuzumab plus ibrutinib will achieve complete response, compared to treatment with ibrutinib alone.
Under the terms of the agreement, Pharmacyclics has committed to supplying ibrutinib to Oncternal during the Phase 1b/2 trial. Oncternal is responsible for conducting the clinical trial.