CTI BioPharma Corp (NASDAQ:CTIC) announced long-term safety and efficacy results from the pivotal Phase 3 PERSIST-1 trial evaluating pacritinib versus best available therapy, excluding treatment with JAK2 inhibitors (BAT), in patients with myelofibrosis. As previously reported, the PERSIST-1 trial met its primary endpoint in the intent-to-treat population with statistically significant reduction in spleen volume when compared to patients receiving BAT. The results represent an update on the efficacy and safety for all patients regardless of their initial platelet count, including patients with very low platelet counts at study entry, a condition known as severe or life-threatening thrombocytopenia. The most frequently occurring adverse events with pacritinib were gastrointestinal events and incidence decreased over time. For patients crossing over to receive pacritinib treatment (84 percent of BAT patients), less than 5 percent of patients had diarrhea with only one patient experiencing grade 3. Patients in the BAT arm that crossed over to receive pacritinib treatment had a similar rate of events as patients initially randomized to BAT or pacritinib. A planned analysis of the study up to 72 weeks demonstrated treatment with pacritinib led to durable reductions in spleen volume and symptom burden, two key measures of disease control, in patients with myelofibrosis, including patients with low platelets at baseline (less than 50,000 per microliter and less than 100,000 per microliter). Patients who crossed over to pacritinib from BAT experienced similar reductions in spleen volume and symptom burden as patients initially randomized to pacritinib, including patients with low platelets. Pacritinib is an investigational oral kinase inhibitor with specificity for JAK2, FLT3, IRAK1 and CSF1R, which are kinases found to be involved in the growth and spread of myelofibrosis and other blood-related cancers.

“From the time a patient is diagnosed with myelofibrosis, the incidence of disease-related thrombocytopenia increases with time,” stated Claire Harrison, M.D., Consultant Hematologist, Guy’s and St. Thomas’ NHS Foundation Trust, Guy’s Hospital, London, United Kingdom and one of the principal investigators for PERSIST-1. “Patients with thrombocytopenia have significantly greater symptom burden, distinct clinical characteristics and shorter overall survival. There is currently a significant unmet need for patients with myelofibrosis who are unable to tolerate or control their disease on other treatments due to low platelet counts.

Dr. Harrison added, “It is encouraging to see that patients with baseline thrombocytopenia who were treated with pacritinib, had stable mean platelet counts and hemoglobin levels through the end of treatment, and that some patients with very low platelets increased their platelet counts while receiving pacritinib treatment. In this intermediate- to high-risk patient group, pacritinib was generally well tolerated.” (Original Source)

Shares of CTI BioPharma are up nearly 12% to $0.48 in pre-market trading. CTIC has a 1-year high of $2.31 and a 1-year low of $0.25. The stock’s 50-day moving average is $0.47 and its 200-day moving average is $0.77.

CTI BioPharma Corp. operates as a biopharmaceutical company, which is focused on the acquisition, development, and commercialization novel targeted therapies covering a spectrum of blood-related cancers. Its products include Pixuvri, Pacritinib, Tosedostat and Opaxio.