Improved Outcomes in Patients Treated with Ruxolitinib After Hydroxyurea

Recent research validates the efficacy of ruxolitinib treatment following hydroxyurea use in patients with polycythemia vera, according to a study presented at the Eleventh Annual Meeting of the Society of Hematologic Oncology.

“Resistance/intolerance to first-line hydroxyurea occurs in ~24% of patients with polycythemia vera (PV); ruxolitinib is recommended in second-line,” the investigators wrote.

The investigators conducted a longitudinal analysis to examine the characteristics and outcomes of patients with polycythemia vera receiving ruxolitinib after hydroxyurea.

Data from 1,053 patients with polycythemia vera who were receiving hydroxyurea ≥3 months before enrollment were included in the analysis. The patients were categorized into two groups: those who switched to ruxolitinib after hydroxyurea (HU-RUX, n=147) and those who continued hydroxyurea treatment (HU; n=906). Various parameters were compared between the groups at specific time points, including diagnosis time, treatment duration, symptom severity, spleen size, blood parameters, and thrombotic event (TE) history.

Regarding the results of the study, the investigators wrote, “Patients who switched to ruxolitinib had more severe disease burden versus hydroxyurea, and demonstrated improved PV-related symptoms, spleen size reduction, and sustained blood parameter improvements.”

Patients in the HU-RUX group exhibited a longer median time from diagnosis (6.9 years) compared with those on HU (4.8 years). Hydroxyurea discontinuations were mainly due to ineffectiveness (36.1%), toxicity (32.0%), and progression (6.8%). Additionally, HU-RUX patients had more severe disease characteristics at baseline, including higher symptom scores (27.5 vs 17.3), more palpable spleens (40.8% vs 9.3%), elevated white blood cell counts (18.1% vs 7.8%), and a higher history of thrombotic events (27.2% vs 19.3%).

Among HU-RUX patients, 62.6% received the recommended initial ruxolitinib dose. Median ruxolitinib treatment duration was 1.9 years, with 89.1% continuing for ≥6 months. 25.9% required dose adjustments, while 84.4% remained on ruxolitinib. HU-RUX patients experienced significant improvements after 12 months in terms of lower Myeloproliferative Neoplasm Symptom Assessment Form total symptom scores (-4.4 vs -5.2) and mean spleen length (-4.9 cm vs -5.8 cm).

The investigators also found the need for phlebotomies substantially decreased in HU-RUX patients. The average number of phlebotomies decreased from 1.3 to 0.5 six months post-index, and 74.8 percent no longer required phlebotomies 12 months post-index.

Lastly, the HU-RUX group demonstrated a lower rate of TEs (2.7%) compared with patients in the HU group (4.2%).

The outcomes validate the efficacy of ruxolitinib treatment following hydroxyurea use.

“Monitoring patients receiving hydroxyurea may identify those likely to benefit from switching to ruxolitinib,” they wrote.

Reference

Gers A, Grunwald M, Oh S, et al. Characteristics and clinical outcomes in patients with polycythemia vera receiving ruxolitinib after hydroxyurea: a longitudinal analysis from the prospective observational study of patients with polycythemia vera in US clinical practices trial (REVEAL). Abstract MPN-574. Presented at the Eleventh Annual Meeting of the Society of Hematologic Oncology; September 6-9, 2023; Houston, Texas.