Aptevo Therapeutics (APVO) was advancing almost 7% Wednesday after the company said the first patient with acute myeloid leukemia dosed in a phase 1b/2 trial evaluating its mipletamig immune-oncology candidate together with standard of care venetoclax and azacitidine achieved a 90% reduction in leukemic blasts within the first 30 days of treatment.

The encouraging initial results continue the overall efficacy, safety and tolerability seen for mipletamig in prior studies, alongside evidence of durable remission, the biotechnology company said.

The open-label study is evaluating the combination of mipletamig with standard of care treatments as frontline combination therapy for leukemia in as many of 39 patients who will be treated across five dosing levels.