Leiden, The Netherlands, May 1, 2014 (GLOBE NEWSWIRE) -- Prosensa Holding N.V. (NASDAQ: RNA) the Dutch biopharmaceutical company focusing on rare diseases with a high unmet medical need, yesterday provided the data analysis of its second open-label extension study (DEMAND IV/DMD114349) of drisapersen in boys with Duchenne Muscular Dystrophy (DMD) during the 66 th American Academy of Neurology (AAN) Annual Meeting in Philadelphia, PA. The Company also provided an update on the drisapersen clinical program earlier this week in a letter sent to patient group representatives and clinical investigators and will present a corporate update during an investor briefing on May 1 (webcast here). Following positive feedback from patients and investigators regarding the willingness and desire of patients to go back on drisapersen and encouraging analyses of its clinical trial data, Prosensa has confirmed that it will re-dose an initial cohort of boys in the third quarter of 2014. The Company has made significant progress in the transition of the program from its former partner, GSK, and expects to communicate on a regulatory path forward for drisapersen before the end of June. In a poster and presentation on Wednesday, April 30 at the AAN, Dr. Nathalie Goemans, Head of the Neuromuscular Reference Center for Children at the University Hospitals Leuven (UHL) in Belgium and one of the key investigators in various drisapersen studies confirmed the earlier preliminary analysis of the results of DEMAND IV/DMD114349, which include data from 96 weeks of continuous drisapersen treatment. "We see very positive signs of the ability of drisapersen to improve the walking ability of boys with DMD. In this extension study, patients who entered the study with a less advanced stage of the disease either improved or experienced less decline in mobility with two-year continuous drisapersen therapy, and these data suggest a treatment difference from those initially on placebo," reported Dr. Goemans.