Characteristics and treatment of polycythemia vera patients in clinical practice: a multicenter chart review on 1476 individuals in Germany.

PURPOSE: Treatment recommendations for patients with polycythemia vera (PV) are well established. Most multicenter trials investigating novel therapeutic strategies for PV are developed and conducted at university hospitals and specialized academic centers. The majority of patients in Germany, however, are treated in an outpatient (ambulatory) setting. The aim of this study was to evaluate the 'real-life' situation in a cohort of 1467 patients by analyzing data from a survey conducted at private practices and primary care centers.
METHODS: Eligible private practices and primary care centers treating patients with MPN were recruited to participate in a paper-pencil-based survey conducted from March 2015 until March 2016 in Germany. Hematologists were asked to report from patient charts. Descriptive analyses were conducted to assess for outcomes examined by reported prognostic risk scores, symptom scores and clinical response criteria.
RESULTS: In total, 34 centers participated in our retrospective survey and provided data on 1476 patients. Most patients were of older age (66.7 % older than 66 years of age), which was the main risk factor according to the criteria published by Tefferi and colleagues. Molecular status at diagnosis was not evaluated in 23 % of patients. Low rates of constitutional symptoms were reported in this physician-based survey with concentration problems, fatigue and itching being the main PV-related symptoms. Phlebotomy and hydroxyurea were the main cytoreductive measures for hematocrit control. The majority of patients were responsive (67.8 %) and tolerant (77.3 %) to hydroxyurea therapy. Interferon and JAK inhibitor therapy were used in <10 % of patients, respectively. Overall, leukocytosis, thrombocytosis and hematocrit could be effectively controlled by any therapy applied. Lack of efficacy was reported on reduction of constitutional symptoms and splenomegaly.
CONCLUSIONS: The patient population investigated was older than participants in published large multicenter trials. The majority of patients were categorized as 'high risk.' Age was the main risk factor. Molecular status was unavailable in the majority of patients diagnosed prior to 2008. The physician-based survey reported on significantly lower rates of constitutional symptoms than patient-based surveys in the literature. Consistent with previously published reports, hydroxyurea is the main agent used for PV therapy in an outpatient setting resulting in efficient control of hematopoietic parameters. Constitutional symptoms and splenomegaly, however, may not be reduced efficiently, which could be improved by the use of JAK inhibitor treatment for high-risk patients in the future.