- JAK inhibitor
- Indications include myelofibrosis, polycythemia, and steroid-refractory graft-versus-host disease
- Adverse effects include ecchymosis, headache, dizziness, abdominal pain, diarrhea, and fatigue, as well as anemia and thrombocytopenia and occasional neutropenia
- May increase risk of herpes zoster infection
- May increase risk of basal cell carcinoma and squamous cell carcinoma
