Xencor Announces Partial Clinical Hold Lifted on Phase 1 Study of XmAb®14045

April 30, 2019 |

3 min read

Xencor, Inc. announced the U.S. Food and Drug Administration has lifted the partial clinical hold that was placed on the Phase 1 study of XmAb14045, a CD123 x CD3 bispecific antibody molecule being evaluated in patients with relapsed or refractory acute myeloid leukemia and other CD123-expressing hematologic malignancies.

April 30, 2019 12:01 UTC

MONROVIA, Calif.--(BUSINESS WIRE)-- Xencor, Inc. (NASDAQ:XNCR), a clinical-stage biopharmaceutical company developing engineered monoclonal antibodies for the treatment of cancer, autoimmune diseases, asthma and allergic diseases, today announced the U.S. Food and Drug Administration (FDA) has lifted the partial clinical hold that was placed on the Phase 1 study of XmAb14045, a CD123 x CD3 bispecific antibody molecule being evaluated in patients with relapsed or refractory acute myeloid leukemia and other CD123-expressing hematologic malignancies. The decision follows discussion and agreement with the FDA on amendments to the study protocol, including guidance on the monitoring and clinical management of cytokine release syndrome.

“We are working with investigational sites to resume enrollment based on the amended protocol, through which we have sought to enhance the safety of patients participating in the study,” said Paul Foster, M.D., senior vice president and chief medical officer at Xencor.

About XmAb^®14045

XmAb14045 is a tumor-targeted antibody that contains both a CD123 binding domain and a cytotoxic T-cell binding domain (CD3) in a Phase 1 clinical trial for the treatment of acute myeloid leukemia (AML) and other CD123-expressing hematologic malignancies. An XmAb^® Bispecific Fc domain serves as the scaffold for these two antigen binding domains and confers long circulating half-life, stability and ease of manufacture on XmAb14045. CD123 is highly expressed on AML cells and leukemic stem cells, and it is associated with poorer prognosis in AML patients. Engagement of CD3 by XmAb14045 activates T cells for highly potent and targeted killing of CD123-expressing tumor cells.

About Xencor, Inc.

Xencor is a clinical-stage biopharmaceutical company developing engineered monoclonal antibodies for the treatment of cancer, autoimmune diseases, asthma and allergic diseases. Currently, 12 candidates engineered with Xencor’s XmAb^® technology are in clinical development internally and with partners. Xencor’s XmAb antibody engineering technology enables small changes to the structure of monoclonal antibodies resulting in new mechanisms of therapeutic action. For more information, please visit www.xencor.com.

Forward-Looking Statements

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