Pacritinib Improves Symptom Relief in Patients With Myelofibrosis Requiring RBC Transfusions

Pacritinib significantly improves symptom relief and transfusion independence in myelofibrosis (MF) patients requiring red blood cell transfusions (RBC) compared with best available therapy (BAT), including ruxolitinib, according to an analysis of the phase III PERSIST-2 study. The results were presented at the Society of Hematologic Oncology 2024 Annual Meeting in Houston, Texas.

Investigators focused on patients randomized to receive either pacritinib (200 mg twice daily) or BAT for at least 12 weeks prior to study termination. The analysis evaluated the proportion of patients achieving transfusion independence response (TI-R), as well as symptom improvement as measured by Total Symptom Score (TSS) and Patient Global Impression of Change at week 24.

The analysis included three groups: pacritinib (n=35), BAT (n=34), and ruxolitinib as BAT (n=13). Baseline characteristics were similar across groups.

Results showed a significant improvement in symptom response, with 31% of patients on pacritinib achieving ≥50% TSS response compared with 9% for BAT (P=0.034) and only 15% for ruxolitinib. Among the 11 pacritinib patients with TSS response, 54.5% also achieved TI-R, whereas none from the BAT group did.

Furthermore, in patients with baseline platelets <50×10⁹/L, pacritinib exhibited a TSS response of 24% compared with 10% for BAT and 11% for ruxolitinib. Reductions in spleen- and cytokine-related symptoms contributed to improved TSS.

Additionally, 37% of patients on pacritinib reported symptoms as “very much” or “much” improved versus 9% for BAT and 8% for ruxolitinib (P=0.009).

“These findings are consistent in showing that pacritinib compared to BAT or low-dose ruxolitinib provides substantial symptom benefit in those patients who require RBC transfusions,” the investigators wrote.

Reference

Oh S, McCloskey J, Sobas M, et al. Impact of pacritinib on symptoms in thrombocytopenic myelofibrosis patients who require red blood cell transfusion. Abstract #MPN-497. Presented at the Society of Hematologic Oncology Annual Meeting; September 4-7, 2024; Houston, Texas.