Shares of CTI BioPharma (CTIC -0.23%) had plunged 21.4% as of 12:23 p.m. ET on Wednesday. The steep decline came after the company announced that the U.S. Food and Drug Administration (FDA) extended the review period for an approval decision of pacritinib in treating myelofibrosis.
The FDA pushed back the review period for pacritinib by three months. As a result, the decision date for the agency under the Prescription Drug User Fee Act (PDUFA) is now Feb. 28, 2022.
What's behind this delay? The FDA required additional clinical data, which CTI submitted on Nov. 24. But the agency views this submission as a "major amendment" to the original New Drug Application (NDA) filing and needs more time to complete its review. The good news is that CTI currently isn't aware of any major deficiencies that the FDA has identified in the NDA filing.
The company's NDA was based on data from phase 3 and phase 2 studies that showed significant improvement in patients receiving pacritinib. The drug is an oral kinase inhibitor that specifically targets JAK2, IRAK1, and CSF1R enzymes but not JAK1.
CEO Adam Craig said that the company "is continuing to engage collaboratively and constructively with the FDA during review of our NDA." Craig added that CTI remains "confident in pacritinib's potential to establish a new standard of care" in treating myelofibrosis. The company also thinks that the experimental drug holds the potential to be used to treat other blood cancers including acute myeloid leukemia, myelodysplastic syndrome, chronic myelomonocytic leukemia, and chronic lymphocytic leukemia.