GSK-Prosensa DMD Candidate Drisapersen Flops in Phase III Trial
GlaxoSmithKline (GSK) and Prosensa said today their investigational drug drisapersen for Duchenne muscular dystrophy (DMD) failed to meet its primary endpoint in a Phase III clinical study—namely, statistically significant improvement in the six-minute walking distance (6MWD) test compared to placebo.
Worse, there was no treatment difference in three key secondary assessments of motor function: a 10-meter walk/run test, a 4-stair climb, and the North Star Ambulatory Assessment.
Results have been submitted for presentation at forthcoming scientific meetings and will also be submitted for publication in a scientific peer-reviewed journal, the companies said. A full evaluation of drisapersen’s benefit-to-risk profile across all studies is anticipated to be completed by year’s end.
GSK and Prosensa had been expected to apply for FDA marketing approval early next year.
“We are committed to evaluating the outcome of this study in the context of the overall development program with experts in the field, and we expect such evaluation to help inform our next steps for drisapersen,” Carlo Russo, svp and head of rare diseases research & development at GSK, said in a statement.
Prosensa CEO Hans Schikan said his company is disappointed that the trial’s primary endpoint was not met, it remains “committed to the overall program and will continue to work closely with GSK.”
Drisapersen (previously known as GSK2402968 and PRO051) is an antisense oligonucleotide which induces exon skipping of exon 51. The drug is one of two DMD treatments seeking to become the first to reach the market; the other is Sarepta’s eteplirsen, which showed improvement in all of a dozen boys studied in a Phase II trial. According to results published in June, boys who had taken eteplirsen showed a 6MWD improvement of 46.4 meters.
GSK obtained an exclusive worldwide license to develop and commercialize drisapersen from Prosensa in 2009, in a deal that offered Prosensa up to £428 million ($685 million) in milestone payments, plus a low-teen percentage of royalties on any sales.
Drisapersen has been given orphan drug status in the European Union, the United States, and Japan. In June, the drug candidate also was granted breakthrough therapy designation by the FDA.