CTI BioPharma has completed patient enrolment in the PAC203 Phase II trial evaluating the safety and efficacy of pacritinib for the treatment of patients with primary or secondary myelofibrosis.
The open-label, randomised, dose-finding trial enrolled 150 patients with primary myelofibrosis, post-polycythemia vera myelofibrosis, or post-essential thrombocythemia myelofibrosis who were previously treated with ruxolitinib.
CTI BioPharma will randomise patients in a 1:1:1 ratio to receive once daily 100mg, twice daily 100mg and 200mg doses of pacritinib over a period of 24 weeks.
The trial’s primary endpoint is the percent reduction in spleen volume from baseline as assessed by MRI or CT scan.
Its secondary endpoints include the percentage of patients with common terminology criteria for adverse events (CTCAE) grade ≥3 cardiac adverse events (AEs), grade ≥3 hemorrhage AEs, grade ≥4 thrombocytopenia toxicity, or grade ≥4 anemia toxicity.
Topline efficacy and safety data from the trial are expected to be published in the third quarter of this year.
CTI BioPharma also plans to identify the optimal dose of pacritinib this year.
The company said in a statement: “As previously announced, the company has received input from the US Food and Drug Administration (FDA) on key elements of the design of a new randomised Phase III study of pacritinib in adult patients with myelofibrosis and who have severe thrombocytopenia, an indication that has been recognised by the medical community as an important unmet medical need.
“A planned interim safety review by an Independent Data Monitoring Committee (IDMC) is scheduled to occur in the first quarter of 2019.”
CTI BioPharma is expected to start patient enrolment for the new Phase III in the third quarter of this year.