How We Identify and Manage Patients with Inadequately Controlled Polycythemia Vera

Hospital incidence and medical costs of polycythemia vera in Spain: a retrospective database analysis

BACKGROUND

Polycythemia vera (PV) is one of the most common chronic myeloproliferative neoplasms, yet, little data is available on the epidemiology of PV in Spain and the costs of its management. This study aimed to evaluate the hospital incidence and mortality rate of PV in Spain, and to estimate hospital medical costs.

METHODS

Hospital admission records of patients with PV registered between 2005 and 2019 were obtained from a Spanish hospital discharge database and analyzed in a retrospective multicenter study.

RESULTS

Admission files of 490 patients were reviewed. Median age was 74 years; patients presented numerous conditions associated to age, namely hypertension, diabetes or anemia. Hospital mortality rate was associated to pulmonary heart disease, respiratory conditions and kidney disease. Most of the files analyzed corresponded to inpatient admissions; hospital incidence decreased over the study period in patients over 60 years. Median admission cost was €5580, increasing in patients deceased during the hospitalization. Admission cost increased significantly between 2006 and 2011.

CONCLUSIONS

This study provides an evaluation of hospital management and costs of PV in Spain. Future studies should focus on the revision of disease management in the country and measuring total medical costs, which could be higher than global estimations.

Long-term efficacy and safety of ruxolitinib versus best available therapy in polycythaemia vera (RESPONSE): 5-year follow up of a phase 3 study

BACKGROUND

Polycythaemia vera is a myeloproliferative neoplasm characterised by excessive proliferation of erythroid, myeloid, and megakaryocytic components in the bone marrow due to mutations in the Janus kinase 2 (JAK2) gene. Ruxolitinib, a JAK 1 and JAK 2 inhibitor, showed superiority over best available therapy in a phase 2 study in patients with polycythaemia vera who were resistant to or intolerant of hydroxyurea. We aimed to compare the long-term safety and efficacy of ruxolitinib with best available therapy in patients with polycythaemia vera who were resistant to or intolerant of hydroxyurea.

METHODS

We report the 5-year results for a randomised, open-label, phase 3 study (RESPONSE) that enrolled patients at 109 sites across North America, South America, Europe, and the Asia-Pacific region. Patients (18 years or older) with polycythaemia vera who were resistant to or intolerant of hydroxyurea were randomly assigned 1:1 to receive either ruxolitinib or best available therapy. Patients randomly assigned to the ruxolitinib group received the drug orally at a starting dose of 10 mg twice a day. Single-agent best available therapy comprised hydroxyurea, interferon or pegylated interferon, pipobroman, anagrelide, approved immunomodulators, or observation without pharmacological treatment. The primary endpoint, composite response (patients who achieved both haematocrit control without phlebotomy and 35% or more reduction from baseline in spleen volume) at 32 weeeks was previously reported. Patients receiving best available therapy could cross over to ruxolitinib after week 32. We assessed the durability of primary composite response, complete haematological remission, overall clinicohaematological response, overall survival, patient-reported outcomes, and safety after 5-years of follow-up. This study is registered with ClinicalTrials.gov, NCT01243944.

FINDINGS

We enrolled patients between Oct 27, 2010, and Feb 13, 2013, and the study concluded on Feb 9, 2018. Of 342 individuals screened for eligibility, 222 patients were randomly assigned to receive ruxolitinib (n=110, 50%) or best available therapy (n=112, 50%). The median time since polycythaemia vera diagnosis was 8·2 years (IQR 3·9-12·3) in the ruxolitinib group and 9·3 years (4·9-13·8) in the best available therapy group. 98 (88%) of 112 patients initially randomly assigned to best available therapy crossed over to receive ruxolitinib and no patient remained on best available therapy after 80 weeks of study. Among 25 primary responders in the ruxolitinib group, six had progressed at the time of final analysis. At 5 years, the probability of maintaining primary composite response was 74% (95% CI 51-88). The probability of maintaining complete haematological remission was 55% (95% CI 32-73) and the probability of maintaining overall clinicohaematological responses was 67% (54-77). In the intention-to-treat analysis not accounting for crossover, the probability of survival at 5 years was 91·9% (84·4-95·9) with ruxolitinib therapy and 91·0% (82·8-95·4) with best available therapy. Anaemia was the most common adverse event in patients receiving ruxolitinib (rates per 100 patient-years of exposure were 8·9 for ruxolitinib and 8·8 for the crossover population), though most anaemia events were mild to moderate in severity (grade 1 or 2 anaemia rates per 100 patient-years of exposure were 8·0 for ruxolitinib and 8·2 for the crossover population). Non-haematological adverse events were generally lower with long-term ruxolitinib treatment than with best available therapy. Thromboembolic events were lower in the ruxolitinib group than the best available therapy group. There were two on-treatment deaths in the ruxolitinib group. One of these deaths was due to gastric adenocarcinoma, which was assessed by the investigator as related to ruxolitinib treatment.

INTERPRETATION

We showed that ruxolitinib is a safe and effective long-term treatment option for patients with polycythaemia vera who are resistant to or intolerant of hydroxyurea. Taken together, ruxolitinib treatment offers the first widely approved therapeutic alternative for this post-hydroxyurea patient population.

FUNDING

Novartis Pharmaceuticals Corporation.

Symptom Burden and Blood Counts in Patients With Polycythemia Vera in the United States: An Analysis From the REVEAL Study

BACKGROUND

Approximately 50% of patients with polycythemia vera (PV) have PV-related symptoms at diagnosis; these symptoms might develop or worsen with time. Symptoms have been shown to negatively affect quality of life and interfere with daily activities. To our knowledge, an analysis to evaluate the relationship between blood count control and symptoms has not been published.

PATIENTS AND METHODS

The Prospective Observational Study of Patients with Polycythemia Vera in US Clinical Practices (REVEAL; NCT02252159) is a multicenter, noninterventional, nonrandomized prospective observational study of patients with PV in the United States. Patients included were required to have a complete blood count result within 30 days before completing the at-enrollment Myeloproliferative Neoplasm Self-Assessment Form Total Symptom Score (MPN-SAF TSS). Symptom severity was compared between those who had blood count control versus those who did not.

RESULTS

At the time of enrollment, 1714 patients (94.5%) were being managed with cytoreductive therapy; 468 patients (25.8%) had complete hematologic remission (CHR), 1614 patients (89.0%) had ≥1 controlled blood count, and 1122 patients (61.9%) had ≥2 controlled blood counts. Mean MPN-SAF TSSs were similar across patients in different blood count control groups. Fatigue was the most frequently reported symptom. The severity of individual symptoms, except those of pruritus and night sweats, was not affected by CHR or the number of blood counts that were controlled.

CONCLUSION

Symptom burden in patients with PV can persist despite control of blood counts, which suggests some discordance between laboratory values and symptom burden. Consequently, regular monitoring of symptom burden should be factored into the assessment of disease control.

Ruxolitinib for the treatment of inadequately controlled polycythemia vera without splenomegaly: 80-week follow-up from the RESPONSE-2 trial

RESPONSE-2 is a phase 3 study comparing the efficacy and safety of ruxolitinib with the best available therapy (BAT) in hydroxyurea-resistant/hydroxyurea-intolerant polycythemia vera (PV) patients without palpable splenomegaly. This analysis evaluated the durability of the efficacy and safety of ruxolitinib after patients completed the visit at week 80 or discontinued the study. Endpoints included proportion of patients achieving hematocrit control (< 45%), proportion of patients achieving complete hematologic remission (CHR) at week 28, and the durability of hematocrit control and CHR. At the time of analysis, 93% (69/74) of patients randomized to ruxolitinib were receiving ruxolitinib; while in the BAT arm, 77% (58/75) of patients crossed over to ruxolitinib after week 28. No patient remained on BAT by week 80. Among patients who achieved a hematocrit response at week 28, the probability of maintaining response up to week 80 was 78% in the ruxolitinib arm. At week 80, durable CHR was achieved in 18 patients (24%) in the ruxolitinib arm versus 2 patients (3%) in the BAT arm. The safety profile of ruxolitinib was consistent with previous reports. These data support that ruxolitinib treatment should be considered also as a standard of care for hydroxyurea-resistant/hydroxyurea-intolerant PV patients without palpable splenomegaly.

From leeches to personalized medicine: evolving concepts in the management of polycythemia vera

Polycythemia vera is a clonal disorder of hematopoietic stem/progenitor cells. It manifests as an expansion of red cell mass. It is the most common chronic myeloproliferative neoplasm. In virtually all cases, it is characterized by a V617F point mutation in JAK2 exon 14 or less common mutations in exon 12. The landmark discovery of the autonomously activated JAK/STAT signaling pathway paved the way for the clinical development of the first target drug, the JAK1 and JAK2 inhibitor ruxolitinib. This is now approved for patients with resistance or intolerance to hydroxyurea. Phlebotomies and hydroxyurea are still the cornerstone of treatment, and aim to prevent the first appearance or recurrence of cardiovascular events that, together with progression to post-polycythemia vera myelofibrosis and leukemia, represent the main causes of death. Interferon-α is an alternative drug and has been shown to induce molecular remissions. It is currently undergoing phase III trials that might eventually lead to its approval for clinical use. The last few years have witnessed important advances towards an accurate early diagnosis of polycythemia vera, greater understanding of its pathogenesis, and improved patient management. This review will focus on the most recent achievements and will aim to unify the different concepts involved in a personalized approach to the patient with polycythemia vera. In spite of many recent advances in the understanding of its pathogenesis and improved disease management, polycythemia vera remains a life-threatening myeloproliferative neoplasm for which there is no cure. This review will present a critical overview of evolving concepts in diagnosis and treatment of this disease.