BeiGene Ltd.'s investigational drug zanubrutinib in combination with tislelizumab showed a reduction in disease for 40% of patients with B-cell malignancies in an ongoing phase 1b trial.
The trial of zanubrutinib, a Bruton's Tyrosine Kinase inhibitor in combination with tislelizumab, an anti-PD-1 antibody, included 13 patients with indolent lymphoma, including chronic lymphocytic leukemia, follicular lymphoma, marginal zone lymphoma, and Waldenström's macroglobulinemia, and 12 patients with aggressive lymphoma, including diffuse large B-cell lymphoma, mantle cell lymphoma and transformed lymphoma.
The data presented at the 59th American Society of Hematology annual meeting showed objective responses in 10, or 40%, of patients. By tumor type, two out of five patients with chronic lymphocytic leukemia showed partial responses, while there was one complete response and one partial response out of the five patients with follicular lymphoma.
One very good partial response and one minor response were observed out of the two patients with Waldenström's macroglobulinemia, one complete response was observed out of five patients with diffuse large B-cell lymphoma and three partial responses were observed out of five patients with transformed lymphoma.
Enrollment of patients with Waldenström's macroglobulinemia was stopped after autoimmune hemolysis occurred in two patients, with one qualifying as a dose-limiting toxicity.