Dive Brief:
- CTI BioPharma announced earlier this week its Phase 3 trial of pacritinib met its primary endpoint when tested against the best available therapy, including Jakafi (ruxolitinib), in myelofibrosis patients. Pacritinib showed a statistically significant 35% or greater reduction in spleen volume when compared with best available therapy.
- The PERSIST-2 trial included 311 patients, but only 221 patients were assessable at 24 weeks.
- Despite meeting one endpoint, the drug failed to meet a co-primary endpoint of a 50% improvement in total symptom score.
Dive Insight:
CTI was optimistic about the results, despite missing the second co-primary endpoint.
"Having analyzed data from two Phase 3 trials with the only JAK inhibitor to be studied in severely thrombocytopenic patients, including patients on JAK2 therapy or those who failed prior JAK2, we are encouraged by pacritinib's clinical profile in this difficult-to-treat group of patients with myelofibrosis," said CTI President and CEO James Bianco.
But optimism isn't going to move this drug forward. The FDA slapped a full clinical hold on the drug in February, citing the high incidence of adverse events and patient deaths in the drug arm of this trial and another Phase 3 trial. Full clinical holds require companies to stop all administration of the drug and stop recruiting any new patients.
While a clinical hold does not necessarily mean development is over for a drug, it usually takes significant evidence from the drugmaker to persuade the FDA to lift such a hold, especially in light of patient deaths.