Fig. 1: Time on pegylated interferon-α (pegIFN), treatment discontinuations, blood counts, correlations of parameters with achievement of clinicohematologic response in pegIFN-treated essential thrombocythemia (ET) patients, and course of the JAK2 V617F variant allele frequency (VAF) over time.

A Swimmer plot for time on pegIFN for 127 ET patients. B Proportion of ET patients who discontinued pegIFN by year and reasons for treatment discontinuation. Market withdrawal of pegIFN-2b was excluded as reason for discontinuation in this illustration. C Platelet (PLT) and white blood cell (WBC) counts at start, best response, and last follow-up in 110 patients with ET treated with pegIFN. Data are represented as median with interquartile range. Statistically significant differences were determined by Friedman’s test followed by Dunn’s multiple comparison test (*p < 0.05, ****p < 0.0001). D Effect of prior cytoreductive therapy, IPSET-thrombosis category, JAK2 V617F mutation status and sex on achieving a complete clinicohematologic response with pegIFN. Multivariate logistic regression analysis was used to determine odds ratios and 95% confidence intervals. E JAK2 V617F VAF before and until 8 years after pegIFN start in 14 patients for which samples were available measured by ddPCR (sensitivity of 10⁻³). Data are represented as median with interquartile range.