Effectiveness of Ropeginterferon Alfa-2B in High-Risk Patients with Philadelphia Chromosome Negative Myeloproliferative Neoplasms- Evaluation of Clinicohaematologic Response, and Safety Profile: Single Centre Experience.

Background: Treatment of Philadelphia chromosome negative myeloproliferative neoplasms (Ph - MPNs) requires individualized approach depending on multiple factors. Novel pegylated Interferon (IFN) formulations have become an attractive therapeutic option in young Ph- MPN patients associated with better patient compliance. Methods: In this retrospective observational study a total of 16 high-risk Ph- MPN patients treated off-label with ropeginterferon alfa-2b given twice monthly, were included. Median follow-up was 24 months. High-risk patients were defined using the IPSET score. Response to treatment was evaluated using ELN, IWG-MET EUMNET standardized criteria and occurrence of side effects was documented. Results: 11 patients were female (68.8%) and 5 male (31.2%); average age at diagnosis was 36 years (17-51); 12 patients (75%) had ET, one (6.2%) PV and three (18.8%) hypercellular phase of PMF. JAK2V617F mutation was detected in 10 patients (62.5%), CALR in three (18.8%), and three (18.7%) were triple-negative cases. In 7 patients (43.7%), ropeginterferon alfa-2b was used in first-line, and 9 (56.3%) were previously treated with HU and/or standard IFN. Among initially ropeginterferon alfa-2b treated patients, complete haematological response was observed in 4/7 (57.1%), partial in 2/7 (28.6%) and suboptimal in one (14.3%). Complete haematological response was observed in 8/9 (88.9%) among previously treated patients. Average time to blood count normalization was 8 weeks, at a dose ranging between 100mcg and 300mcg. Side effects were observed in one patient (6.2%). Conclusion: Our experience is in support of previous studies regarding ropeginterferon alfa-2b efficacy and safety profile in the treatment of young patients with Ph- MPNs.