On February 1, 2019 CTI BioPharma Corp. (NASDAQ: CTIC) reported that the Company will withdraw its European Marketing Authorization Application (MAA) for pacritinib as a treatment for myelofibrosis (Press release, CTI BioPharma, FEB 1, 2019, View Source [SID1234533006]). The decision follows recent interactions with the European Medicine Agency’s (EMA) Committee for Medicinal Products for Human Use (CHMP), during which the Company learned that the committee was likely to formally adopt a negative opinion in its evaluation of the application. The CHMP indicated that the risk-benefit profile for pacritinib for the intended indication has not been sufficiently established with the clinical data available to date.
The Company is continuing to develop pacritinib for both U.S. and European registration as a treatment for myelofibrosis patients with severe thrombocytopenia. CTI plans to seek scientific guidance from the EMA before beginning the planned Phase 3 study, having already discussed the protocol design with the FDA last month. The Phase 3 trial is expected to begin enrollment in the third quarter of 2019.
In addition, the Company announced that on January 23, 2019, a planned third interim review of the PAC203 study was held by the Independent Data Monitoring Committee (IDMC) and the study will continue as scheduled. The IDMC did not identify significant drug- or dose-related safety concerns and specifically did not identify any concerns around hemorrhagic or cardiac toxicity.
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 (AML), myelodysplastic syndrome (MDS), chronic myelomonocytic leukemia (CMML), and chronic lymphocytic leukemia (CLL), due to its inhibition of c-fms, IRAK1, JAK2 and FLT3.