Prosensa Reports Initial Findings from the Further Clinical Data Analyses of Drisapersen for the Treatment of Duchenne Muscular Dystrophy

Prosensa Holding N.V.

, the Dutch biopharmaceutical company focusing on RNA-modulating therapeutics for rare diseases with high unmet medical need, today announced initial findings from further analyses from the aggregate data from the clinical development program of drisapersen for the treatment of Duchenne Muscular Dystrophy (DMD)."We are encouraged by these results that suggest that treating earlier in the disease and treating longer shows a delay in the progression of the disease," said Hans Schikan, Prosensa's Chief Executive Officer. "These data encourage us to engage patient groups, clinical experts and regulators to explore a path forward for drisapersen, which includes the possibility of re-dosing."Schikan will be presenting details of the further data analyses at the 32nd Annual J.P. Morgan Healthcare Conference in San Francisco on Thursday, January 16, 2014 at 10:00 AM Pacific Time. A live webcast of the presentation can be accessed through the Investors & Media section of the Prosensa corporate website at http://ir.prosensa.eu/events.cfm  and will be archived for 90 days.With data from more than 300 patients Prosensa has the largest clinical data set in DMD. In order to advance the general understanding of DMD, Prosensa has also announced that it will make certain data from the drisapersen clinical program available to the scientific community. In addition it has initiated a