Haematologic reactions are expected and manageable1
Anaemia and thrombocytopenia are expected adverse reactions associated with JAKAVI therapy, based on the mechanism of action1
- JAK signalling plays an important role in haematopoiesis by mediating the activity of growth factors, including EPO and TPO2
- Anaemia and thrombocytopenia are expected consequences of JAK inhibition because erythropoietin and thrombopoietin signal through JAK22
- Anaemia and thrombocytopaenia were the most common adverse reactions during JAKAVI therapy; however, they rarely led to treatment discontinuation1,3
- 2 patients (1%) discontinued treatment due to anaemia1
- 7 patients (3.6%) discontinued treatment due to thrombocytopaenia1
Percentage of MF patients treated with JAKAVI with haematologic adverse reactions3,a

aAll MF patients (n=301) randomised to and treated with JAKAVI from COMFORT-I and COMFORT-II.
bCTCAE version 3.0; Grade 1=mild, Grade 2=moderate, Grade 3=severe, Grade 4=life-threatening.
- Incidence of Grade 3 or 4 anaemia and thrombocytopenia typically present early in the treatment course with JAKAVI (≤6 months) and decreased with long-term therapy1
Anaemia gradually recovered to reach a new steady state that was approximately 5 g/L below baseline and was manageable1,3
Haemoglobin levels over time1

Adapted from: Cervantes F et al. Blood. 2013;122:4047-4053.1
JAKAVI included both randomised and extension phases; BAT included randomised phase only and did not include assessments after crossover.
- Haemoglobin levels generally decrease after starting JAKAVI therapy, reaching a nadir after 8 to 12 weeks of therapy and thereafter gradually recovering to reach a new steady state that was approximately 5 g/L below baseline1,3
Thrombocytopenia was generally reversible and manageable3
Platelet counts over time1

Adapted from: Cervantes F et al. Blood. 2013;122:4047-4053.1
JAKAVI included both randomised and extension phases; BAT included randomised phase only and did not include assessments after crossover.
- Median onset of Grade 3/4 thrombocytopenia was 8 weeks, and median time to recovery of platelet counts above 50,000/mm3 was 14 days3