Ruben Mesa, MD of the Mayo Clinic, Phoenix, AZ discusses the results of the PERSIST-1 and PERSIST-2 Phase III studies of pacritinib versus best alternative therapy (BAT) in myelofibrosis patients. The PERSIST-1 study (NCT01773187) in patients who were JAK (Janus kinase) inhibitor naïve, showed favorable results but also excess mortality. The PERSIST-2 study (NCT02055781) looked at pacritinib versus BAT in patients with platelet counts less than 100,000µl; patients did not have to be JAK inhibitor naïve. The results indicate that pacritinib in a 200 mg twice daily dose (BID) is superior to BAT in terms of spleen response, symptoms, safety, and likely survival. The 400 mg dose was shown to be not as favorable. Prof. Mesa also discusses concerns around toxicity raised by PERSIST-1; results point to a slight safety advantage for the 200 BID dose. Overall, Prof. Mesa concludes the data was favorable and he hopes this study will allow a path forward for this agent to become a resource for myelofibrosis patients. Recorded at the 2016 American Society of Hematology (ASH) Annual Meeting, held in San Diego, CA.