FDA Lifts Clinical Hold on Pacritinib for the Treatment of Myelofibrosis

The U.S. Food and Drug Administration (FDA) has lifted the full clinical hold placed on all clinical trials of pacritinib – an oral kinase JAK2/FLT3 inhibitor – for treatment for myelofibrosis (MF).

The FDA placed the hold on pacritinib in February 2016 after two phase III trials (PERSIST-1 and PERSIST-2) resulted in deaths related to intracranial hemorrhage, cardiac failure, and cardiac arrest. The FDA suggested that the drug’s manufacturer (CTI BioPharma) conduct dose-exploration studies, submit final study reports and data sets for PERSIST-1 and PERSIST-2, make certain modifications to protocols and study-related documents, and request a meeting with the FDA prior to submitting a response to the full clinical hold.

As a result, CTI BioPharma is planning the PAC203 trial, which will evaluate the safety and dose-response relationship for efficacy (defined as spleen volume reduction at 24 weeks) of pacritinib at three doses: 100 mg once daily, 100 mg twice daily, and 200 mg twice daily (this was the dose used in PERSIST-2). Investigators plan to enroll approximately 105 patients with primary MF who have failed prior ruxolitinib therapy.

Source: CTI BioPharma news release, January 6, 2017.