麻豆传媒

The FDA granted to pacritinib (Vonjo) for the treatment of adult patients with intermediate- or high-risk primary or secondary myelofibrosis with severe thrombocytopenia, CTI BioPharma announced.

Pacritinib is a novel oral kinase inhibitor with specificity for JAK2, IRAK1, and CSF1R, without inhibiting JAK1. The accelerated approval was based on results from the phase III , which found that 29% of patients receiving pacritinib 200 mg had a reduction in spleen volume of at least 35% compared with 3% of patients receiving best available therapy.

"Today's approval of Vonjo establishes a new standard of care for myelofibrosis patients suffering from cytopenic myelofibrosis," said John Mascarenhas, MD, of the Icahn School of Medicine at Mount Sinai in New York City, in a press release. "Myelofibrosis with severe thrombocytopenia, defined as blood platelet counts below 50 × 10⁹/L, has been shown to result in poor survival outcomes coupled with debilitating symptoms. Limited treatment options have rendered this disease as an area of urgent unmet medical need. I am pleased to see that a new, efficacious and safe treatment option is now available for these patients."

In the PERSIST-2 trial, patients with myelofibrosis and severe thrombocytopenia were randomized 1:1:1 to receive pacritinib 200 mg twice daily, pacritinib 400 mg once daily, or best available therapy, including ruxolitinib (Jakafi), hydroxyurea, and prednisone/prednisolone.

The most common adverse reactions (≥20%) in the 200-mg pacritinib cohort were diarrhea, thrombocytopenia, nausea, anemia, and peripheral edema. The most frequent serious adverse reactions (≥3%) were anemia, thrombocytopenia, pneumonia, cardiac failure, disease progression, pyrexia, and squamous cell carcinoma of the skin.

Drug interruptions due to adverse reactions occurred in 27% of patients who received pacritinib 200 mg twice daily compared with 10% of patients treated with best available therapy, while dose reductions occurred in 12% and 7%, respectively. Permanent discontinuation due to an adverse reaction occurred in 15% of patients receiving pacritinib compared with 12% of patients treated with best available therapy.

In FDA's of the approval, the agency noted that "patients must not use Vonjo if they are also taking certain other medicines, such as strong CYP3A4 inhibitors or inducers."

Results from the are expected in mid 2025, CTI BioPharma said.

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