Real-world, retrospective study evaluating thromboembolic events, associated risk factors, and health-care resource utilization in Japanese patients with polycythemia vera.

In this retrospective, real-world study, we used medical claims data to evaluate the incidence of thromboembolic events (TEs), time to TE, associated risk factors, and health-care resource utilization (HRU) in Japanese patients with polycythemia vera (PV; N = 606) from April 1, 2008, to August 31, 2015. Baseline characteristics of interest included median age, 67.0 years; previous TEs, 11.6%; cardiovascular conditions (CVCs), 45.7%; and ≥ 3 risk factors, 17.8%. Overall, 100 patients experienced TEs (118 events) at a rate of 8.15/100 person-years [TE-free survival rate, 69.3% (2008-2015)]. The annual total health-care costs [mean (per person)] were significantly impacted by the presence of TEs (yes vs. no: ¥993,000 vs ¥459,000; P < 0.001). These results confirm that the presence of CVCs increases the risk of TEs in Japanese patients with PV; occurrence of TEs was associated with a higher HRU in these patients.

Evaluation of the dose and efficacy of ruxolitinib in Japanese patients with myelofibrosis.

Ruxolitinib, a potent JAK1/JAK2 inhibitor, improved splenomegaly and myelofibrosis-associated symptoms and prolonged survival compared with placebo and best available therapy in the phase 3 COMFORT studies. Although cytopenias were the most common adverse events associated with ruxolitinib treatment, a COMFORT-I analysis showed that they were managed effectively with dose modifications, without a negative impact on the efficacy of ruxolitinib. Subsequently, studies A2202 and AJP01 showed that ruxolitinib is an effective treatment for Japanese patients with myelofibrosis. We conducted a pooled analysis of these two studies (N = 81) to evaluate the association between ruxolitinib dose and changes in spleen volume or symptoms in Japanese patients. Most patients began treatment at 15 or 20 mg twice daily (BID); 70% received a final titrated dose ≥ 10 mg BID. Overall, 91% of patients exhibited spleen volume reductions; patients with final titrated doses ≥ 10 mg BID had larger spleen volume reductions. Similarly, 83% of patients showed improvements in symptom scores; those with a final titrated dose of 20 or 25 mg BID had the greatest reductions. Consistent with COMFORT-I, this pooled analysis indicates that, despite dose adjustments, ruxolitinib provides spleen and symptom control in Japanese patients, with higher doses associated with better responses.

Assessing the safety and efficacy of ruxolitinib in a multicenter, open-label study in Japanese patients with myelofibrosis.

Ruxolitinib is a potent JAK1/JAK2 inhibitor that has demonstrated durable improvements in splenomegaly, symptoms, and overall survival in controlled clinical trials in patients with myelofibrosis. The single-arm study reported here was initiated to collect further safety and efficacy data in Japanese patients with myelofibrosis and is the largest study of ruxolitinib in this population. The primary objective was to assess safety. Secondary endpoints included changes in spleen size and patient-reported outcomes. The primary analysis occurred when all patients (N = 51) completed 24 weeks or discontinued. Overall, 86.3% of patients completed treatment; 9.8% discontinued due to adverse events (AEs). Consistent with previous studies, the most common AEs were anemia (62.7%) and thrombocytopenia (29.4%). Furthermore, levels of select immunologic biomarkers remained stable, and no deaths occurred. At week 24, 30.0% of evaluable patients experienced ≥50% reductions from baseline in palpable spleen length; 26.0% had ≥35% reductions in spleen volume. Additionally, ruxolitinib led to clinically significant improvements in symptoms and quality of life. Overall, findings from this study indicate that ruxolitinib is safe and effective in Japanese patients with myelofibrosis, with these benefits extending to patients with intermediate-1-risk myelofibrosis and to those with low platelet counts.