The US Food and Drug Administration (FDA) has placed a partial clinical hold on trials conducted under the investigational new drug
(IND) application for pacritinib.
Pacritinib is a JAK2/FLT3 inhibitor being developed by CTI BioPharma for the treatment of myelofibrosis (MF).
The partial clinical hold impacts part of the clinical work currently being conducted under the pacritinib IND and will also affect planned clinical trials.
The FDA said the reasons for the partial clinical hold are excess mortality and other adverse events in pacritinib-treated patients (compared to the control arm) in the PERSIST-1 trial.
The excess mortality was most evident during the non-randomized crossover period following the initial 24 weeks of randomized treatment, during which patients in the control arm could switch to pacritinib treatment.
Under the partial clinical hold, investigators may not enroll new patients or start pacritinib as initial or crossover treatment, and patients not deriving benefit after 30 weeks of pacritinib treatment must stop using pacritinib.
In addition, the FDA has recommended that CTI BioPharma make certain modifications to protocols, provide certain notifications, revise relevant statements in the related investigator’s brochure and informed consent documents, and take certain other actions.
CTI BioPharma said it intends to implement the FDA’s recommendations, and all clinical investigators worldwide have been notified of the partial clinical hold.
Just before the FDA notified CTI BioPharma of the partial clinical hold, the company completed enrollment in the phase 3 PERSIST-2 trial.
In PERSIST-2, researchers are comparing the efficacy and safety of pacritinib and best available therapy in patients with thrombocytopenia and primary MF, post-polycythemia vera MF, or post-essential thrombocythemia MF.
Under the partial clinical hold, patients on this trial who are currently receiving pacritinib may continue to do so unless they are not deriving benefit after 30 weeks of pacritinib treatment, and crossover of patients from the control arm to the pacritinib arm will not be allowed.
