Facing rejection, CTI pulls European filing for pacritinib

Shares in CTI fell 8% in premarket trading following the news. (CC0 Public Domain)

CTI BioPharma has pulled its European filing for approval of pacritinib in myelofibrosis. The biotech took the action after learning that the Committee for Medicinal Products for Human Use (CHMP) was likely to advise against approving the oral kinase inhibitor.

Seattle-based CTI has already put pacritinib through two phase 3 trials in the bone marrow disorder myelofibrosis but has found regulators unsupportive of its data package. Last year, the FDA told CTI to run another phase 3 in the indication before filing for approval, leaving Europe as the biotech’s best shot of picking up a near-term approval in a major market.

Now, that door has closed on CTI, too. CTI filed for approval of pacritinib in the European Union in 2017 and went through two rounds of questioning by regulators, during which it used data from an ongoing open-label phase 2 to bolster its case.

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The effort seemingly failed to convince the European Medicines Agency’s CHMP that the risk-benefit profile of pacritinib supports approval. With CHMP likely to issue a negative opinion about the drug, CTI has withdrawn the filing.

Shares in CTI fell 8% in premarket trading following the news. The stock is down more than 75% on the highs it hit before a late-phase trial of Pixuvri missed its primary endpoint and the FDA asked CTI to run another phase 3 trial of pacritinib in July.

CTI now plans to talk to the EMA before starting a phase 3 trial it hopes will address the doubts of regulators on both sides of the Atlantic. The biotech has already discussed the protocol with the FDA and expects to begin enrollment in the third quarter.

Data from a phase 2 dose-finding trial, PAC203, are due around the same time. CTI initiated the trial to confirm that 200mg twice a day has the best risk-benefit profile of any pacritinib regimen. The trial recently completed its third review by the independent committee and was cleared to continue.