[Sustained hematologic complete response after discontinuation of ropeginterferon alfa-2b in patients with polycythemia vera].

We report two cases of polycythemia vera (PV) treated with ropeginterferon alfa-2b (ropeg-IFN) in which hematologic control was maintained without therapy after treatment discontinuation. The patients achieved complete response (CR) at 14 and 22 weeks after treatment initiation, respectively. After discontinuation of ropeg-IFN, Patient 1 has maintained hematocrit (Ht) <45% for 3 years and 3 months, while patient 2 has maintained CR for 1 year and 5 months. Clinical trials have demonstrated that ropeg-IFN reduces the JAK2 V617F allele burden, which is recognized as an independent risk factor for disease progression and thrombosis, apart from traditional factors such as age and prior cardiovascular events. To improve the prognosis of PV, it is essential to accumulate clinical evidence on trends in JAK2 V617F allele burden and the conditions required to maintain hematologic control after discontinuation of ropeg-IFN therapy in real-world settings.