Early evidence from a Phase I dose-escalation study of the bispecific antibody AMG 330 in 55 patients with relapsed or refractory AML showed acceptable safety, tolerability, and anti-leukemic activity, meriting further dose escalation, researchers reported at the ASCO virtual annual meeting in June.
AMG 330 was administered on 4 schedules, with 0 to 3 dose steps based on the AE profile, before reaching the target dose of 720 mcg/day. Eight of 42 evaluable patients responded to treatment (3 CRs, 1 of which was MRD negative; 4 CRs with incomplete hematologic recovery; 1 morphologic leukemia-free state). Four responders had an adverse cytogenetic risk profile; 3 had received 4 or more prior lines of therapy.
Forty-nine patients (89%) reported study-drug–related AEs, of which the most frequent were CRS (67%; grade 3 or higher 13%) and nausea (20%). The frequency and severity of CRS correlated with the dose level and baseline leukemic burden, the researchers said.