FDA approved Vonjo (pacritinib) for Myelofibrosis with Low Platelet CountsFDA approved new drug Vonjo for rare bone marrow cancer with low platelets.

Not reported in label.

Vonjo is indicated for the treatment of adults with intermediate or high-risk primary or secondary (post-polycythemia vera or post-essential thrombocythemia) myelofibrosis with a platelet count below 50 × 10^9/L. This indication is approved under accelerated approval based on spleen volume reduction. Continued approval may be contingent upon verification and description of clinical benefit in a confirmatory trial(s).

The recommended dosage is 200 mg orally twice daily, with or without food. Swallow capsules whole; do not open, break, or chew. For patients with severe hepatic impairment (Child-Pugh C), the recommended dosage is 100 mg twice daily, which may be increased to 200 mg twice daily if not effective after 12 weeks and no safety concerns. Dose modifications are specified for diarrhea, thrombocytopenia, hemorrhage, and prolonged QT interval. Discontinue Vonjo 7 days prior to elective surgery or invasive procedures due to hemorrhage risk; restart only after hemostasis is assured.

The efficacy of Vonjo was established in the PERSIST-2 trial, which enrolled patients with intermediate or high-risk primary or secondary myelofibrosis with splenomegaly and a platelet count ≤100 × 10^9/L. Both JAK2 naïve patients and those with prior JAK2 inhibitor therapy were included. Patients were randomized 1:1:1 to receive Vonjo 400 mg once daily, Vonjo 200 mg twice daily, or best available therapy. The primary endpoint was spleen volume reduction. Specific efficacy results are not detailed in the label.

Vonjo has warnings and precautions for diarrhea, thrombocytopenia, hemorrhage, and prolonged QT interval. Dose modification tables are provided for each adverse reaction. For life-threatening bleeding, discontinue Vonjo. For QTc prolongation >500 msec or >60 msec from baseline, hold Vonjo and restart at same or reduced dose depending on resolution time.

Vonjo provides a treatment option for adults with intermediate or high-risk myelofibrosis and severe thrombocytopenia (platelet count <50 × 10^9/L), a population often excluded from clinical trials of other JAK inhibitors. Its approval is based on spleen volume reduction, and confirmatory trials are required to verify clinical benefit.