Pacritinib Improves Thrombocytopenia, Anemia in Myelofibrosis

One year of pacritinib stabilized or improved thrombocytopenia and anemia in patients with myelofibrosis (MF), according to a recent study. The retrospective trial was led by Michael Marrone, PhD, of Sobi Inc., and presented at the Twelfth Annual Meeting of the Society of Hematologic Oncology in Houston, Texas.

“Thrombocytopenic MF is challenging to manage, and patients with platelets (PLT) <50 × 10⁹/L have limited median overall survival (OS) of 15 months,” wrote Dr. Marrone and colleagues.

The researchers obtained data on 142 patients with MF who were treated with pacritinib from the Integra-PrecisionQ database. Treatment-related outcomes included PLT levels, hemoglobin (Hb) levels, and OS from pacritinib initiation to the end of the study period. The median treatment exposure was 5.3 months, and the median follow-up was six months.

Thirty-four of 119 (28.5%) patients had severe thrombocytopenia (PLT<50 × 10⁹/L), and 35 (29%) patients had severe anemia (Hb <8.0 g/dL). The median PLT count (× 10⁹ /L) was 81 at initiation (n=119) and 96 at day 360 after initiation (n=15). The median Hb level was 8.8 g/dL at initiation (n=119) and 10.4 g/dL at day 360 after initiation (n=15).

The one-year OS probability was 69.4% (95% CI, 56.8–79.0) overall, 77.3% (95% CI, 61.5–87.3) in 1L pacritinib, and 75.2% (95% CI, 46.3–90.0) in 1L pacritinib with initiation PLT <50 × 10⁹/L.

“OS among 1L pacritinib users compared favorably with other [Janus kinase] inhibitor historical controls,” the researchers concluded.

Reference

Marrone M, Geller R, Oladapo A, et al. Real-world treatment patterns and outcomes in patients with myelofibrosis treated with pacritinib in the United States. Abstract #MPN-386. Presented at the Twelfth Annual Meeting of the Society of Hematologic Oncology. September 4-7, 2024; Houston, Texas.