Approaches to the Treatment of Patients with Myelofibrosis and Polycythemia Vera with Constitutional Symptoms in Real-World Clinical Practice in the Russian Federation: Intermediate Results of a Multi-Center Observational Prospective Clinical Study

Abstract

Aim. To describe the methods of drug therapy implemented for the disease control in patients with polycythemia vera (PV) and myelofibrosis (MF) as well as to analyze manifestations and severity of the disease symptoms in real-world clinical practice.
 Materials & Methods. The analysis focused on the data of 1229 patients. In 629 (51.18 %) patients, PV was diagnosed, MF was identified in 521 (42.39 %) patients. The diagnosis of 79 (6.43 %) patients was not reported. Early stage of primary MF (PMF) was detected in 182 (34.93 %) patients, PMF fibrosis stage was identified in 251 (48.18 %) patients, post-polycythemic MF was registered in 61 (11.71 %) patients, and 13 (2.5 %) patients showed post-thrombocythemic MF. In 14 (2.69 %) patients, MF type was not reported. By the time of diagnosis, the median age of PV patients was 56 years (range 17–86 years), and that of MF patients was 55 years (range 16–83 years) (p = 0.022). The proportion of women among PV patients was 57 %, among MF patients it was 65 % (p = 0.0065).
 Results. The assessment of thrombotic complication risk in PV showed that 51.01 % (n = 302) of patients belong to the low-risk, 39.86 % (n = 236) belong to the intermediate-risk, and only 9.12 % (n = 54) of patients belong to the high-risk groups. Distribution of MF patients between risk groups demonstrates favorable prognosis for most patients. The group of low and intermediate-1 risks includes 56.43 % (n = 294) patients according to the prognostic scoring system IPSS and 68.52 % (n = 357) according to the prognostic scoring system DIPSS. In the vast majority of cases, patients received hydroxycarbamide therapy: 81.81 % (n = 832) in the total cohort, 83.33 % (n = 465) in the PV group, and 79.96 % (n = 367) in the MF group. Interferon-α was administered to 19.71 % (n = 110) of PV patients and 29.85 % (n = 137) of MF patients. Ruxolitinib was assigned to 3.14 % (n = 19) of PV patients and 21.35 % (n = 98) of MF patients.
 Conclusion. Regular monitoring of the PV and MF course and treatment efficacy can provide recommendations for adequate change of therapy in case of the failure of previous treatment. It should be emphasized that the timely switch to the second-line therapy results in reduced disability and mortality among PV and MF patients with myeloproliferative neoplasms.