Pacritinib (Vonjo)

Mechanism of action

From the NCI Drug Dictionary: An orally bioavailable inhibitor of Janus kinase 2 (JAK2) and the JAK2 mutant JAK2V617F with potential antineoplastic activity. Pacritinib competes with JAK2 for ATP binding, which may result in inhibition of JAK2 activation, inhibition of the JAK-STAT signaling pathway, and so caspase-dependent apoptosis. Also, per Hart et al. 2011 pacritinib is a tyrosine kinase inhibitor (TKI) with equipotent activity against FLT3 (IC₅₀=22 n) and Janus kinase 2 (JAK2, IC₅₀=23 n).

Diseases for which it is used

• Myelofibrosis

History of changes in FDA indication

• 2022-03-01: Granted accelerated approval 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 x 10⁹/L. (Based on PERSIST-2)

Also known as

• Code name: SB-1518
• Brand name: Vonjo