About Vadastuximab Talirine (SGN-CD33A; 33A)
SGN-CD33A is a novel antibody-drug conjugate (ADC) targeting CD33, which is expressed on most acute myeloid leukemia (AML) cells. 33A utilizes our newest ADC technology comprising a highly potent DNA binding agent, a pyrrolobenzodiazepine (PBD) dimer, attached via a proprietary site-specific conjugation technology to a monoclonal antibody with engineered cysteines (EC-mAb). PBD dimers are significantly more potent than systemic chemotherapeutic drugs and the site-specific conjugation technology allows uniform drug-loading of the cell-killing PBD agent to the anti-CD33 antibody. The ADC is designed to be stable in the bloodstream and to release its potent DNA binding agent upon internalization into CD33-expressing cells.
33A is being evaluated in several ongoing and planned phase 1 and phase 1/2 clinical trials. A phase 3 clinical trial for newly diagnosed patients with AML is planned for 2016.