BeiGene falls on immune events for B cell cancer combo

BeiGene Ltd. (NASDAQ:BGNE) lost $4.59 to $91.39 Monday after reporting three immune-related events in a Phase Ib trial of zanubrutinib (BGB-3111) plus tislelizumab (BGB-A317) to treat B cell malignancies at the American Society of Hematology meeting in Atlanta. Zanubrutinib is a selective oral Bruton’s tyrosine kinase (Btk) inhibitor and tislelizumab is a humanized IgG4 mAb against PD-1.

Of 25 patients treated in the first two dose cohorts of the open-label trial’s dose escalation portion, there were two cases of autoimmune hemolysis, each in patients with Waldenstrom's macroglobulinemia (WM), and a case of grade 4 autoimmune encephalitis in a patient with indolent lymphoma. One of the autoimmune hemolysis events qualified as a dose-limiting toxicity. BeiGene has said it discontinued enrollment of WM patients...