Positive topline results from the pivotal AGAVE-201 trial of axatilimab in chronic graft-versus-host disease.- Syndax Pharma + Incyte

The trial achieved its primary endpoint across all cohorts, with patients treated with axatilimab at doses of 0.3 mg/kg every two weeks, 1.0 mg/kg every two weeks and 3.0 mg/kg every four weeks demonstrating overall response rates (ORR) within the first six months of treatment of 74%, 67% and 50%, respectively (95% Confidence Interval [CI]) .

Responses were achieved across key patient subgroups, including those with prior exposure to ruxolitinib, belumosudil and/or ibrutinib. Based on these results, and pending agreement from the FDA, Syndax and Incyte intend to submit a Biologics License Application (BLA) to the FDA by year-end 2023.

The AGAVE-201 pivotal study enrolled a total of 241 patients across 121 sites in 16 countries. Patients enrolled in the trial had received a median of four prior systemic therapies with 74% having previously received ruxolitinib, 23% having previously received belumosudil and 31% having previously received ibrutinib. 54% of these patients had at least four organs involved at baseline including 45% with lung involvement.

Among responders treated with 0.3 mg/kg of axatilimab, 60% of patients maintained a response at 12 months (measured from first response to new systemic therapy or death, based on the Kaplan Meier estimate). The median duration of response in this population has not been reached. Additionally, in the 0.3 mg/kg group, 55% of patients experienced a clinically meaningful improvement in symptoms, as measured by at least a seven-point decrease in the modified Lee chronic GVHD Symptom Scale score.

The most common adverse events were consistent with the on-target effects of CSF-1R inhibition and with what was previously observed with axatilimab treatment. In the overall population, adverse events in greater than 20% of patients include an increase in aspartate aminotransferase, blood creatine phosphokinase, lipase, blood lactate dehydrogenase, alanine aminotransferase and fatigue (n=239). Serious adverse events in the overall population occurred in 101 (42.3%) patients, with 37 (15.5%) patients experiencing adverse events leading to discontinuation of study treatment. In the 0.3 mg/kg dose group (n=79), fatigue was the only serious adverse event that occurred in greater than 20% of patients. Serious adverse events in the 0.3 mg/kg group occurred in 30 (38%) patients, with five (6.3%) patients experiencing adverse events leading to discontinuation of study treatment.