Doses at or above 215 μg/kg had the best outcomes, with an overall response rate (ORR) of 70% (n = 14). Out of the 215-, 360-, 600-, and 1000-μg/kg dose groups, the highest dose had the best outcomes, with an 83.3% ORR, including 16.7% of patients with a complete response, 50% with a very good complete response, and 16.7% with a partial response. Median time to response was 22 days, ranging from 21 to 50 days.

There were 14 patients with IMWG-confirmed response; in this cohort, median duration of response was not reached. There was a 92.3% probability (95% CI, 56.7-98.9) of responders being event-free at 6 months.

Within the entire study population, the most common all causality treatment-emergent adverse events (AEs) were

• lymphopenia (83.3%; grade 3, 20% and grade 4, 60%),
• cytokine release syndrome (CRS; 73%; all grade 1 and 2);
• anemia (57%; grade 3, 43% and grade 4, 3%);
• injection site reaction (53%; none above grade 2);
• thrombocytopenia (53%; grade 3, 23% and grade 4, 17%);
• and neutropenia (40%; grade 3, 17% and grade 4, 17%).

There were no dose-limiting toxicities.