December 12, 2024
Author(s): Kyle Doherty
Fact checked by: Caroline Seymour
Although long-term follow-up was limited, treatment with the JAK2 inhibitors pacritinib (Vonjo) and/or momelotinib (Ojjaara) led to favorable effects on anemia and transfusion requirements among patients with myelofibrosis, according to findings from a real-world study presented in a poster during the 2024 ASH Annual Meeting.1
Patients who received momelotinib (n = 32) had a median hemoglobin count of 8.7 g/dL (range, 6.5-1.2) at the start of therapy which increased to 9.0 g/dL after 3 months of treatment (P = .021). The median platelet count at the start of therapy was 141 x 109/L (range 15 x 109-504 x 109) and increased to 116 x 109/L after 3 months (P = .317). Patients required a mean of 1.9 red blood cell (RBC) units/month at the start of therapy and 0.47 units/month after 3 months of treatment (P = .015).
Patients treated with pacritinib (n = 27) had a median hemoglobin count of 8.5 g/dL (range, 6.9-12.9) at the start of treatment and a median count of 9.1 g/dL following 3 months of therapy (P = .402). The median platelet count at the start of therapy was 65 x 109/L(range, 18 x 109-441 x 109) compared with 31 x 109/L after 3 months of treatment (P = .303). Patients required a mean of 2.4 RBC units/month at the start of therapy vs 0.75 RBC units/month after 3 months of therapy (P = .099).
“The goal of this project was to [examine] the patients who have been treated so far at Moffitt Cancer Center with either pacritinib and/or momelotinib to gain a better understanding of the hematologic responses of these therapies, the duration of treatment, and other real-world data regarding these agents after they got their approvals,” Jeremy DiGennaro, MD, said during the presentation. “Patients receiving momelotinib and pacritinib are typically older with extended disease duration, multiple prior lines of therapy, high-risk mutations, and cytopenia. Pacritinib-treated patients have more prominent baseline thrombocytopenia. [However], there were favorable impacts on anemia and transfusion requirements [with both agents], although we still do need more long-term follow-up.”
DiGennaro is an internal medicine resident physician at the University of South Florida Morsani College of Medicine in Tampa.
In February 2022, the FDA granted accelerated approval to pacritinib for the treatment of adult patients with intermediate or high-risk primary or secondary myelofibrosis with a platelet count below 50,000/µL.2 Momelotinib was approved by the FDA in September 2023 for the treatment of adult patients with intermediate or high-risk myelofibrosis, including primary myelofibrosis or secondary myelofibrosis, and anemia.3