Biotechnology company Seattle Genetics has commenced Phase I trial of a novel antibody-drug conjugate (ADC), SGN-CD33A, in patients with acute myeloid leukaemia (AML).
SGN-CD33A leverages the company’s ADC technology targeted to CD33 antibody, which is attached to a potent cytotoxic DNA-crosslinking agent, a pyrrolobenzodiazepine dimer, by means of a proprietary site-specific conjugation technology to a monoclonal antibody with engineered cysteines.
Seattle Genetics research and translational medicine senior vice-president Jonathan Drachman said SGN-CD33A uses latest technology, combining a highly potent cell-killing agent with a new engineered antibody (EC-mAb) technology that results in uniform drug-loading.
"It is designed to be a highly potent ADC directed to the CD33 antigen, which is found on AML cells," Drachman said.
Designed to assess the safety and anti-leukaemia activity of SGN-CD33A, the open-label, multi-centre, dose-escalation trial will also evaluate pharmacokinetics, progression-free survival and overall survival in patients with CD33-positive AML.
The study’s primary endpoints are the estimation of the maximum tolerated dose and safety assessment of SGN-CD33A.
The dose escalation portion of the study will enrol up to approximately 90 patients at multiple centres in the US and evaluate SGN-CD33A administered every three weeks.
Patients achieving a complete remission will continue to obtain SGN-CD33A at a lower, maintenance dose given every three weeks.
The dose escalation cohorts showing evidence of anti-leukaemia activity possibly will be expanded for further safety and clinical activity assessment.
Image: Bone marrow aspirate showing acute myeloid leukemia. Several blasts have Auer rods. Photo: courtesy of VashiDonsk, en.wikipedia.