Xencor hit by partial clinical hold following trial deaths

Shares in Californian monoclonal antibody specialist Xencor (Nasdaq: XNCR) dropped over 6% on Wednesday, after the firm announced the US regulator had placed a partial clinical hold on its Phase I study of XmAb14045.

The tumor-targeted antibody is being evaluated in people with relapsed or refractory acute myeloid leukemia and other CD123-expressing blood cancers.

The US Food and Drug Administration has imposed the measure after the firm submitted safety reports on two patient deaths that were considered “at least possibly related to XmAb14045.”