A rolling submission of a new drug application (NDA) for the JAK2/FLT3 inhibitor pacritinib has been initiated for patients with myelofibrosis and severe thrombocytopenia defined as platelet counts of less than 50,000 μL, according to a statement from CTI BioPharma, Corp.1 The application is based on available information from the phase 3 PERSIST-1 (NCT01773187) and PERSIST-2 trials (NCT02055781), as well as data from the phase 2 PAC203 trial.

“Today we are pleased to announce the start of a rolling NDA submission that seeks to address the important unmet medical need of [patients with] myelofibrosis with severe thrombocytopenia, a population that includes both frontline treatment-naïve patients and patients with prior exposure to JAK2 inhibitors,” said Adam R. Craig, MD, PhD, president and chief executive officer of CTI Biopharma.1 “We have started pre-commercial activities and are planning for a commercial launch in 2021, subject to priority review.”

In the PERSIST-1 trial, 327 participants were randomized in a 2:1 fashion to receive either pacritinib at a daily dose of 400 mg or physician’s choice of best available therapy, with the exception of ruxolitinib (Jakafi). In the control arm, the most commonly used therapies included hydroxycarbamide (55.7%) and a watch-and-wait approach (25.5%).2
Participants had either primary myelofibrosis, post-polycythemia vera myelofibrosis, or post-essential thrombocytopenia myelofibrosis. No platelet level was required for enrollment. Notably, 32% of patients had platelet levels under 100,000 μL, while 16% had counts below 50,000 μL. 

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