Experience with ruxolitinib in the treatment of myelofibrosis and polycythaemia vera at Czech haematological institutions
Abstract
Backgrounds: Ruxolitinib, a Janus kinase 1 and 2 inhibitor, demonstrated efficacy in patients with myelofibrosis and polycythaemia vera in the randomized COMFORT-I, COMFORT-II and RESPONSE studies. Ruxolitinib demonstrated superior durable reduction of splenomegaly and disease-associated symptoms, maintenance of haematocrit values, improvement in quality of life and overall survival compared to placebo or best available therapy.
Material and Methods: A retrospective analysis evaluated efficacy and tolerability of ruxolitinib in a cohort of unselecte myelofibrosis and polycythaemia vera patients treated in routine clinical practice at 14 Czech haematological centres from 2013 to 2016. Results: Myelofibrosis - a total of 62 patients with myelofibrosis treated with ruxolitinib were evaluated.
The most frequent indication for treatment was concurrent splenomegaly and constitutional symptoms in 54 (87.1%) cases. Reduction * 1/3 in palpable spleen length was achieved in 43 (72.9%) patients with baseline splenomegaly at a median of 4 weeks after starting therapy.
Constitutional symptoms receded in 38 (92.7%) of 41 patients at a median of 4 weeks after starting therapy. While on ruxolitinib, eleven (18.0%) patients developed grade 3-4 anaemia and thirteen (21.3%) patients developed grade 3-4 thrombocytopenia.
Forty six (74.2%) patients survived. Twenty five (40.3%) patients discontinued therapy, most frequently due to inefficacy (16.1% of patients) or haematological toxicity (8.1% of patients).
Median duration of ruxolitinib therapy was 41 weeks. Polycythaemia vera - a total of 8 patients with polycythaemia vera treated with ruxolitinib because of resistance or intolerance of previous treatment was analysed.
Six (75.0%) patients achieved complete remission. All patients experienced resolution of disease-associated symptoms.
No patient developed grade 3 to 4 toxicity. At evaluation, all patients remained on ruxolitinib with a median duration of 32.5 weeks.
Conclusion: Our analysis confirmed the very good treatment efficacy of ruxolitinib in patients with myelofibrosis and polycythaemia vera on reduction of splenomegaly and alleviation of disease-associated symptoms. Ruxolitinib additionally led to the correction of haematocrit values in patients with polycythaemia vera.
Haematological toxicity was generally low.