SEATTLE, WA, USA I August 1, 2017 I CTI BioPharma Corp. (NASDAQ and MTA: CTIC) today announced that the first patient has been enrolled in PAC203, a Phase 2 clinical trial of pacritinib in patients with primary myelofibrosis who have failed prior ruxolitinib therapy. PAC203 is designed to evaluate the dose response relationship for safety and efficacy (spleen volume reduction at 12 and 24 weeks) of three dose regimens: 100 mg once-daily, 100 mg twice-daily (BID) and 200 mg BID. The 200 mg BID dose regimen was used in the Phase 3 PERSIST-2 trial of pacritinib in patients with myelofibrosis. The trial is expected to enroll up to approximately 105 patients. 

About Pacritinib

Pacritinib is an investigational oral kinase inhibitor with specificity for JAK2, FLT3, IRAK1 and CSF1R. The JAK family of enzymes is a central component in signal transduction pathways, which are critical to normal blood cell growth and development, as well as inflammatory cytokine expression and immune responses. Mutations in these kinases have been shown to be directly related to the development of a variety of blood-related cancers, including myeloproliferative neoplasms, leukemia and lymphoma. In addition to myelofibrosis, the kinase profile of pacritinib suggests its potential therapeutic utility in conditions such as acute myeloid leukemia, or AML, myelodysplastic syndrome, or MDS, chronic myelomonocytic leukemia, or CMML, and chronic lymphocytic leukemia, or CLL, due to its inhibition of c-fms, IRAK1, JAK2 and FLT3.

Pacritinib was evaluated in two Phase 3 clinical trials, known as the PERSIST program, for patients with myelofibrosis, with one trial in a broad set of patients without limitations on platelet counts, the PERSIST-1 trial; and the other in patients with low platelet counts, the PERSIST-2 trial. The PERSIST-1 trial met its primary endpoint of spleen volume reduction (35 percent or greater from baseline to Week 24 by MRI/CT scan). The PERSIST-2 trial met one of its co-primary endpoints, that of spleen volume reduction. The co-primary endpoint of reduction of Total Symptom Score (TSS) was not achieved but trended toward improvement in TSS.

Clinical studies under the investigational new drug (IND) for pacritinib were subject to a full clinical hold issued by the FDA in February 2016. In January 2017, the FDA removed the full clinical hold and stated that clinical trials may resume. CTI BioPharma is conducting the PAC203 trial which was a condition of the clinical hold being removed.

About CTI BioPharma Corp.

CTI BioPharma Corp. is a biopharmaceutical company focused on the acquisition, development and commercialization of novel targeted therapies covering a spectrum of blood-related cancers that offer a unique benefit to patients and healthcare providers. CTI BioPharma has a late-stage development pipeline, including pacritinib for the treatment of patients with myelofibrosis. CTI BioPharma is headquartered in Seattle, Washington. For additional information and to sign up for email alerts and get RSS feeds, please visit www.ctibiopharma.com.

SOURCE: CTI BioPharma