Yacoub et al report excellent responses to pegylated interferon alfa-2a in patients with hydroxyurea-resistant/intolerant polycythemia vera or essential thrombocythemia.

The ongoing COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 is a global public health crisis. Multiple observations indicate poorer post-infection outcomes for patients with cancer than for the general population. Herein, we highlight the challenges in caring for patients with acute leukaemias and myeloid neoplasms amid the COVID-19 pandemic. We summarise key changes related to service allocation, clinical and supportive care, clinical trial participation, and ethical considerations regarding the use of lifesaving measures for these patients. We recognise that these recommendations might be more applicable to high-income countries and might not be generalisable because of regional differences in health-care infrastructure, individual circumstances, and a complex and highly fluid health-care environment. Despite these limitations, we aim to provide a general framework for the care of patients with acute leukaemias and myeloid neoplasms during the COVID-19 pandemic on the basis of recommendations from international experts.

The goal of therapy for essential thrombocythemia (ET) and polycythemia vera (PV) patients is to reduce thrombotic events by normalizing blood counts. Hydroxyurea (HU) and interferon-α (IFN-α) are the most frequently used cytoreductive options for ET and PV patients at high-risk for vascular complications. Myeloproliferative Disorders Research Consortium 112 was an investigator-initiated, phase 3 trial comparing HU to pegylated IFN-α (PEG) in treatment naïve, high-risk ET/PV patients. The primary endpoint was complete response (CR) rate at 12 months. A total of 168 patients were treated for a median of 81.0 weeks. CR for HU was 37% and 35% for PEG (p=0.80) at 12 months. At 24/36 months, CR was 20%/17% for HU and 29%/33% for PEG. PEG led to a greater reduction in JAK2V617F at 24 months, but histopathologic responses were more frequent with HU. Thrombotic events and disease progression were infrequent in both arms, while grade 3/4 adverse events were more frequent with PEG (46% vs. 28%). At 12 months of treatment there was no significant difference in CR rates between HU and PEG. This study indicates that PEG and HU are both effective treatments for PV and ET. With longer treatment PEG was more effective in normalizing blood counts and reducing driver mutation burden, while HU produced more histopathologic responses. Despite these differences, both agents did not differ in limiting thrombotic events and disease progression in high-risk ET/PV patients. (Funded by the National Cancer Institute, 5P01CA108671-09; clinicaltrials.gov number (NCT01259856)

Polycythemia vera (PV) is a chronic myeloproliferative neoplasm that is associated with a substantial symptom burden, thrombohemorrhagic complications, and impaired survival. A decade after the seminal discovery of an activating mutation in the tyrosine kinase JAK2 in nearly all patients with PV, new treatment options are finally beginning to emerge, necessitating a critical reappraisal of the underlying pathogenesis and therapeutic modalities available for PV. Herein, we comprehensively review clinical aspects of PV including diagnostic considerations, natural history, and risk factors for thrombosis. We summarize recent studies delineating the genetic basis of PV, including their implications for evolution to myelofibrosis and secondary acute myeloid leukemia. We assess the quality of evidence to support the use of currently available therapies, including aspirin, phlebotomy, hydroxyurea, and interferon. We analyze recent studies evaluating the safety and efficacy of JAK inhibitors, such as ruxolitinib, and evaluate their role in the context of other available therapies for PV. This review provides a framework for practicing hematologists and oncologists to make rational treatment decisions for patients with PV.