FDA Lifts Clinical Hold on Vadastuximab Talirine

The U.S. Food and Drug Administration (FDA) has lifted the clinical hold that was placed on phase 1 trials of vadastuximab talirine (SGN-CD33A; 33A), an investigational antibody-conjugate drug, for treatment of acute myeloid leukemia (AML).

The clinical hold was placed on the two trials on December 27, 2016, following the deaths of four patients who were treated with the investigational agent along with allogeneic hematopoietic cell transplantation (alloHCT). A phase I/II trial of single-agent vadastuximab talirine in pre- and post-alloHCT patients with AML was placed on full clinical hold, while two other phase I trials received partial clinical holds (one assessing vadastuximab talirine in combination with hypomethylating agents in older patients with AML; the other examining vadastuximab talirine in combination with 7+3 chemotherapy in patients with newly diagnosed AML).

The drug’s manufacturers noted that the clinical hold was resolved through a comprehensive re-evaluation of 300 patients and protocol amendments to ensure patient safety, including revising eligibility criteria and protocols for halting treatment in the event of veno-occlusive disease.

Vadastuximab talirine was previously granted orphan drug designation by both the FDA and the European Commission.

Source: Seattle Genetics press release, March 6, 2017.