Phase 1/2 trial of glasdegib in patients with primary or secondary myelofibrosis previously treated with ruxolitinib.

•Glasdegib had an acceptable toxicity profile in patients with myelofibrosis.•Most common adverse events were dysgeusia, muscle spasms, and alopecia.•Modest improvements in patient-reported symptoms were observed with glasdegib.•Spleen volume reduction (SVR) was noted in some patients, but no patient had ≥35% SVR.