Momelotinib treatment-emergent neuropathy: prevalence, risk factors and outcome in 100 patients with myelofibrosis.

Momelotinib (a JAK1 and JAK2 inhibitor) induces both anaemia and spleen responses in myelofibrosis (MF). Momelotinib treatment-emergent peripheral neuropathy (TE-PN) was documented in 44 (44%) of 100 MF patients treated at our institution; median time of TE-PN onset was 32 weeks and duration 11 months. Improvement after drug dose reduction or discontinuation was documented in only two patients. TE-PN was significantly associated with treatment response (P = 0·02) and longer survival (P = 0·048) but significance was lost during multivariate analysis that included treatment duration. TE-PN did not correlate with initial or maximum momelotinib dose or previous treatment with JAK inhibitor or thalidomide.