Interferon-alpha (rIFN?) is the only disease-modifying treatment option for polycythemia vera (PV). A study published in Leukemia found that treatment of PV with rIFN? prevents myelofibrosis (MF) and may prolong survival.
This large, single-center, retrospective study comprised 470 patients with PV (median age at diagnosis, 54 years; range, 20-94 years). Researchers assessed MF-free survival (MFS) and overall survival (OS) in patients treated with rIFN? versus hydroxyurea (HU) or phlebotomy-only (PHL-O).
Median follow-up was 10 years (range, 0-45 years). Half of patients (n=229; 49%) were women, and 208 were high-risk patients (44%). Primary treatment included rIFN? in 93 patients (20%), HU in 189 patients (40%), and PHL-O in 133 patients (28%); 55 patients (12%) received other cytoreductive drugs. The treatment groups differed by European LeukemiaNet risk score (P<0.001).
In low-risk patients, 20-year MFS for rIFN?, HU, and PHL-O was 84%, 65%, and 55%, respectively (P<0.001). Twenty-year OS was 100%, 85%, and 80%, respectively (P=0.44).
In high-risk patients, 20-year MFS for rIFN?, HU, and PHL-O was 89%, 41%, and 36%, respectively (P=0.19), while 20-year OS was 66%, 40%, and 14%, respectively (P=0.016).
Per multivariable analysis, longer time on rIFN? was associated with a lower risk of MF (hazard ratio [HR], 0.91; P<0.001) and lower mortality (HR, 0.94; P=0.012).