Xencor Presents Initial Data from Phase 1 Study of XmAb13676 in B-cell Malignancies at the ASH Annual Meeting
Xencor, Inc. (NASDAQ:XNCR), a clinical-stage biopharmaceutical company developing monoclonal antibodies for the treatment of cancer, autoimmune disease, asthma and allergic diseases, today announced initial data from its ongoing Phase 1 dose-escalation study of XmAb13676, a CD20 x CD3 bispecific antibody, in patients with B-cell malignancies. Data are being presented by Krish Patel, M.D., Director of the Lymphoma Program at Swedish Cancer Institute, in a poster session today from 6:00 p.m. to 8:00 p.m. EST at the 61st American Society of Hematology (ASH) Annual Meeting in Orlando, Florida.
“XmAb13676 has been generally well tolerated and has demonstrated encouraging clinical activity in patients with advanced non-Hodgkin’s lymphoma as a monotherapy in initial dose escalation cohorts. This activity supports the potential of XmAb13676 in lymphoma treatment, and we are planning additional studies as a monotherapy and in combination with other agents,” said Bassil Dahiyat, Ph.D., president and chief executive officer at Xencor. “Dose escalation and optimization of dosing schedule, using a priming dose and step-up regimen, are ongoing.”
At data cut off in November 2019, 45 patients with relapsed/refractory non-Hodgkin’s lymphoma (r/r NHL) had received doses of XmAb13676 ranging from 0.7 to 170 mcg/kg, and 8 patients with relapsed/refractory chronic lymphocytic leukemia (r/r CLL) had received doses ranging from 0.7 to 20 mcg/kg. The study was designed in two parts: Part A to establish an initial priming dose with flat dosing regimens and Part B to escalate dosing on subsequent administrations to the priming dose. Prophylactic treatment for cytokine release syndrome (CRS) was mandated prior to each dose of XmAb13676.
XmAb13676 was generally well tolerated, and a priming dose of 45 mcg/kg was chosen for continued dose escalation in Part B for patients with NHL.
Safety was evaluated in all 53 patients. The most common treatment-emergent adverse events (AEs) were pyrexia (55%), CRS (53%) and anemia (41%). CRS was more frequent and generally higher grade on the first dose. Three patients (6%) experienced Grade 3 or 4 CRS on the first dose, all prior to the implementation of step-up dosing. AEs consistent with the symptoms of CRS, but not reported as such, were observed in an additional 23% of patients and were mild to moderate in severity.