- Results from a Phase 1b clinical trial assessing Seattle Genetics' (NASDAQ:SGEN) Orphan Drug-tagged vadastuximab talirine (SGN-CD33A) showed a treatment benefit in newly diagnosed patients with acute myeloid leukemia (AML). The data were presented at the 58th American Society of Hematology (ASH) annual meeting in San Diego.
- In 42 evaluable patients, 76% (n=32/42) achieved complete remission or complete remission with incomplete platelet or neutrophil recovery. 94% (n=30/32) of the remissions occurred after one cycle of therapy. In higher-risk patients, 86% (n=18/21) achieved remissions. Median overall survival has yet to be reached. 30-day mortality was 2%. Half (n=21/42) subsequently received an allogeneic stem cell transplant.
- The most common grade 3 (severe) or grade 4 (life threatening) treatment-emergent adverse events occurring in at least 20% of patients were febrile neutropenia, thrombocytopenia, anemia and neutropenia (specific incidence rates not provided).
- Vadastuximab talirine is an antibody-drug conjugate comprised of a cysteine monoclonal antibody linked to a highly potent DNA binding agent. The antibody binds to CD33, a transmembrane receptor expressed on acute myeloid leukemia cells. It is being investigated across multiple lines of therapy in patients with myeloid malignancies.