Hydroxyurea Treatment History and Quality of Life in Patients with Polycythemia Vera: Results from the MPN Landmark Survey in the United States

Background: Patients with the myeloproliferative neoplasm (MPN) polycythemia vera (PV) require treatment to manage blood cell counts and reduce the risks of cardiovascular/thromboembolic events. Hydroxyurea (HU) is a common cytoreductive treatment; however, some patients discontinue HU treatment because of resistance, intolerance, or frequently a combination of both limitations. Patients may also continue to receive HU despite diminishing or nonexistent clinical benefit, sometimes in combination with persistent need for phlebotomy procedures. This analysis of MPN Landmark survey data examined patient-reported quality of life (QoL) outcomes in patients with PV who were naive to HU (HU‑N), were continuing HU (HU‑C), or had discontinued HU (HU‑D).

Methods: Patients with an MPN under active management in the US were eligible to complete an online survey (fielded May – July 2014). This is a report of responses given by patients with PV to questions about symptom burden, QoL, activities of daily living (ADL), and work/productivity. PV-related effects on patients feeling depressed/discouraged, patients feeling anxious/worried, or interference with ADLs were considered to be at high levels if the patient-reported score was ≥4 on a scale of 1 (not at all) to 5 (a great deal). Symptom severity was rated on a scale of 0 (absent) to 10 (worst imaginable).

Results: The survey respondents included 380 patients with PV (HU‑N, n=159; HU‑C, n=181; HU‑D, n=40). Mean age was 62.2 years, 65.1 years, and 64.2 years in the HU‑N, HU‑C, and HU‑D groups, respectively. Mean duration of PV was 8.3 years, 10.3 years, and 13.9 years in the HU‑N, HU‑C, and HU‑D groups, respectively. Patients who had not received HU were currently or previously treated with phlebotomy (87.4%), interferon (11.3%), or anagrelide (9.4%); 66.0% of HU‑N patients were classified as high-risk based on information provided by the patients in the survey (ie, age 60 or older or history of thrombosis). Among HU‑C and HU‑D patients, treatment history included phlebotomy (89.5% and 100%, respectively), interferon (7.2% and 52.5%), or anagrelide (15.5% and 35.0%); 79.6% and 82.5%, respectively, were classified as high-risk. Ruxolitinib was not FDA-approved for PV at the time of this survey. Patients reported high levels of feeling anxious/worried and depressed/discouraged as a result of their PV across all subgroups: HU‑N, 27.7% and 15.1%, respectively; HU‑C, 22.7% and 15.5%; HU‑D, 32.5% and 22.5%. Many patients also experienced a high level of PV-related interference with ADLs, which was more common in the HU‑D group (30.0%) than the HU‑N (11.3%) or HU‑C (18.2%) groups. HU‑D patients were more likely to have reported ever reducing their work hours (54.2% of the patients who responded) compared with the HU‑N (33.3%) and HU‑C groups (36.8%). Among all patients, HU‑D patients reported a mean of 8.3 doctor visits in the past 12 months, compared with 5.6 in the HU‑N group and 6.6 in the HU‑C group. Most patients had experienced PV-related symptoms in the past 12 months (Table 1), particularly fatigue, itching, and day/night sweats; fatigue was ranked first as the symptom that patients would most like to resolve.  

Conclusion: Patients with PV in a large retrospective real-world survey across the US are found to experience burdensome PV-related symptoms and reduced QoL. The findings from this study also show that standard treatments do not address these aspects of PV in many patients, and patients who have discontinued HU may experience an even greater disease burden, possibly because of a lack of effective and/or safe alternative treatment options. Importantly, while 66.0% of the patients in the HU‑N group were classified as high-risk, the majority of the high-risk patients in the HU‑N group (81.0%) were not treated with cytoreductive agents, suggesting a potential knowledge deficit regarding recommendations for PV management. Collectively, these results illustrate the adverse impact of PV-related symptom burden on patient QoL and reinforce the importance of unmet control of PV-related symptoms in choosing PV therapy.