Clinical trial of Retrophin drug fails; Shows no benefit for PKAN patients
A much-anticipated drug therapy has failed to show any benefit for individuals affected with PKAN, or Pantothenate Kinase-Associated Neurodegeneration, one of the most common forms of NBIA.
The drug’s maker, Retrophin Inc., announced the disappointing results Aug. 22 for its Phase 3 Fosmetpantotenate Replacement Therapy, or FORT, study.
Seventy-eight PKAN individuals had completed the 24-week randomized, double-blind study, meaning that neither the patients nor the doctors knew who was randomly selected to get the drug or the placebo. At the end of the study, 76 patients decided to participate in the open-label program in which all received the drug.
Although the drug, Fosmetpantotenate, was observed to be generally safe and well-tolerated, the study found that it did not meet its primary or secondary endpoints, or outcome measures.
First, the study found no differences between those who received the drug and those who got the placebo. That determination was based on the extent to which individuals improved over the 24-week trial, based on a scale that measures activities of daily living, such as walking, eating and dressing. Those measures were specifically adapted for PKAN individuals using Part II of the comprehensive and widely referenced Unified Parkinson’s Disease Rating Scale.
Second, the study found no measurable change on the same scale’s Part III score, which evaluates motor function, including slowness, stiffness and balance.
No data suggested that a longer course of treatment would change the outcomes, nor were any differences seen between classic and later-onset PKAN individuals taking part in the trial.
“We are very disappointed in the topline results from the FORT Study, particularly because we have seen the devastating impact of PKAN on patients and their families, and a significant unmet need remains with no approved treatment option,” said Retrophin CEO Eric Dube, Ph.D. "We would like to thank the patients, their caregivers, study investigators and our employees, whose dedication made this study possible.”
The study gathered a significant amount of data, which is still being analyzed. Retrophin plans to present its findings at scientific meetings in the fall. It also will publish the findings in a peer-reviewed journal. Company officials said they hope the data will help inform future clinical studies for treating PKAN.