CALR mutations in essential thrombocythemia are associated with lower thrombosis risk and higher risk of progression to myelofibrosis (MF) compared with other driver mutations, according to a recent study.
The study was led by Katie Erdos, a Research Program Assistant at Weill Cornell Medicine’s Richard T. Silver, MD Myeloproliferative Neoplasms Center, and presented at the 65th American Society of Hematology Annual Meeting & Exposition.
Erdos and colleagues conducted the study to evaluate the impact of driver mutations on the risks of thromboembolic events, disease progression, and patient mortality.
Of 338 total patients, 216 (64%) were positive for JAK2V617F, 85 (25%) were positive for CALR, 19 (6%) were positive for MPL, and 18 were (5%) triple-negative (TN). Red cell parameters were slightly higher in patients with JAK2V617F mutations (P<0.001), white blood cell count was highest in TN patients (P=0.012), and platelet count did not significantly vary across mutation groups (P=0.064).
The 20-year thrombosis-free survival was 71% for JAK2V617F, 100% for CALR, 90% for MPL, and 83% for TN (P=0.0027). The 20-year MF-free survival was 87% for JAK2V617F, 48% for CALR, 65% for MPL, and 94% for TN (P=0.00053). Meanwhile, the 20-year overall survival was 76% for JAK2V617F, 86% for CALR, 89% for MPL, and 90% for TN (P=0.66).
“Our findings reinforce the need for long-term data to guide therapy for ET based not only on the near-term thrombotic risk, but also on the long-term risk of progression,” wrote Erdos and colleagues.
Reference
Erdos K, Lee N, Lebbe A, et al. Low thrombosis risk CALR mutations confer higher risk of essential thrombocythemia progression. Abstract #1819. Presented at the 65th ASH Annual Meeting & Exposition; December 9-12, 2023; San Diego, California.