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# Xencor Leukemia Study Placed on Partial Hold by FDA
- URL: https://www.fdaweb.com/xencor-leukemia-study-placed-on-partial-hold-by-fda/
- Published: 2019-02-20T12:00:00.000Z
- Updated: 2026-09-15T01:06:21.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5143422

FDA has placed a partial clinical hold on a Xencor a 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. Patients currently on the therapy may continue treatment on the study. However, no new patients will be allowed to enroll in the study until the partial clinical hold is lifted by FDA.

The hold was ordered in response to recent safety reports Xencor submitted to FDA on two patient deaths that were considered at least possibly related to XmAb14045, the company says. “One patient experienced cytokine release syndrome (CRS) after their first dose, the treatment of which was complicated by the patient’s decision to withdraw care,” it says. “One patient developed acute pulmonary edema following several doses of XmAb14045.”

The agency has requested additional details about the adverse events, and safety and efficacy information across the study. It also says a satisfactory review of amendments to the study protocol and related documents will need to occur before lifting the hold, according to the company.