[Efficacy and safety of JAK inhibitor ruxolitinib in Chinese patients with myelofibrosis: results of a 1-year follow-up of A2202].

Objective To evaluate the efficacy and safety of ruxolitinib in Chinese myelofibrosis patients. Methods This study enrolled 63 Chinese patients(32 males and 31 females)in total, whose median age was 55(25-79)years. The initial dose of ruxolitinib was 30mg/d(25 patients)with a baseline of PLT(100-200)×109/L and 40 mg/d(38 patients)with a baseline of PLT>200×109/L. Spleen volume, quality of life(QOL)and symptoms were evaluated by MRI/CT, European Organization for Research and Treatment of Cancer QOL Questionnaire Core 30(EORTC QLQ-C30)and MF Symptom Assessment Form(MFSAF)v2.0 questionnaire. Results At the time of this analysis(follow-up of 12 months), 47 patients(74.6%)were still receiving treatment, 25 patients(39.7%)achieved ≥35% reduction in spleen volume from baseline. First time to achieve≥35% reduction was 12.71(95% CI 12.14-35.00)weeks. During the treatment, 85.7%(54 /63)of patients achieved reduction in spleen volume in different extent, the median optimal spleen volume reduction was 35.5% and the median spleen volume reduction was 34.7% at week 48. 53.1%(26/49)of patients achieved ≥50% reduction in spleen volume from baseline in total symptom score and QOL was improved at week 48. The most common hematologic adverse events were anemia and thrombocytopenia, which merely resulted in discontinuation of treatment. Non-hematologic adverse events were almost grade 1/2. Conclusions These data indicated that ruxolitinib treatment provided durable reductions in spleen volume and improvement in symptoms in Chinese myelofibrosis patients, and the adverse events were tolerated. Clinical trial registration Novartis pharma(NCT01392443) Key words: Myelofibrosis; JAK inhibitor; Ruxolitinib; Treatment outcome; Drug toxicity