SEATTLE, Oct. 7, 2013 /PRNewswire/ -- Cell Therapeutics, Inc. (CTI) (NASDAQ and MTA: CTIC) today announced that the company reached agreement with the U.S. Food and Drug Administration (FDA) on a Special Protocol Assessment (SPA) for the planned pivotal Phase 3 clinical trial, known as the PERSIST-2 trial, evaluating pacritinib compared to best available therapy, including approved JAK2 inhibitors such as ruxolitinib, in patients with myelofibrosis whose platelet counts are <100,000/uL. The SPA is a written agreement between CTI and the FDA regarding the design, endpoints and planned statistical analysis approach of the trial to be used in support of a potential New Drug Application (NDA) submission. The PERSIST-2 trial is the second of two planned Phase 3 clinical trials in patients with myelofibrosis. CTI expects to initiate the PERSIST-2 clinical trial in the fourth quarter of 2013. "The FDA worked closely with us to achieve SPA agreement during first cycle review of the PERSIST-2 trial protocol for pacritinib," stated James A. Bianco, M.D., CTI's President and CEO. "As a result of the SPA, which established agreement on trial design to support regulatory approval, we expect that we will be able to initiate this pivotal Phase 3 clinical trial of pacritinib by the end of the year. Myelofibrosis is a chronic disease and JAK inhibitors have had a dramatic impact on the lives of people living with myelofibrosis. Data from earlier studies of pacritinib showed a clinically meaningful improvement in symptoms with minimal suppression of platelets or red blood cells. We believe patients with myelofibrosis, particularly those with low platelet counts, could benefit from new treatment options." PERSIST-2 is a 300 patient randomized, open-label, multi-center pivotal trial in patients with myelofibrosis whose platelet counts are <100,000/uL. The trial will evaluate pacritinib as compared to best available therapy, including approved JAK2 inhibitors that are dosed according to the product label for myelofibrosis patients with thrombocytopenia. Patients will be randomized (1:1:1) to receive 200 mg pacritinib twice daily, 400 mg pacritinib once daily or best available therapy. The agreed upon co-primary endpoints are the percentage of patients achieving a 35 percent or greater reduction in spleen volume measured by MRI or CT at 24 weeks of treatment and the percentage of patients achieving a Total Symptom Score (TSS) reduction of 50 percent or greater using six key symptoms as measured by the modified Myelofibrosis Symptom Assessment Form (MF-SAF) diary. The trial is expected to enroll patients at clinical sites in the United States, Europe and Australia. Pacritinib Development Strategy Based on pacritinib's efficacy and tolerability profile demonstrated to date, CTI is pursuing a broad approach to advancing this therapy for myelofibrosis patients by conducting two Phase 3 clinical trials: one in a broad set of patients without limitations on blood platelet counts, the PERSIST-1 trial, and the other in patients with low platelet counts, the PERSIST-2 trial, as described above, which is expected to begin in the fourth quarter of 2013.