Prosensa To Host Conference Call To Discuss Recent Drisapersen Data Presentations

Leiden, The Netherlands, Oct. 3, 2013 (GLOBE NEWSWIRE) -- Prosensa Holding N.V. (NASDAQ: RNA), the Dutch biopharmaceuticalcompany focusing on RNA-modulating therapeutics for rare diseaseswith high unmet need, will hold a conference call on Tuesday,October 8, 2013 at 11:00 a.m. ET / 5:00 p.m. CET to discussrecently-presented data on drisapersen, an investigationalantisense oligonucleotide, for the treatment of Duchenne MuscularDystrophy (DMD) patients with an amenable mutation, which isexclusively licensed to GlaxoSmithKline (GSK).

Prosensa Chief Executive Officer Hans Schikan will be joined byGiles Campion, Prosensa's Chief Medical Officer & SeniorVice-President of Research and Development and Judith van Deutekom,Vice President of Drug Discovery to discuss the recently presentedresults from studies of drisapersen. These include results fromDEMAND III (Phase III; DMD114044); DEMAND II (Phase II; DMD114117);DEMAND V (Phase II; DMD114876) and 177 week data from the PhaseI/II extension study (DMD114673).

The data were presented at the DIA/FDA Oligonucleotide basedTherapeutics Conference in Washington DC, the 18th World MuscleSociety Congress in Asilomar, California and the 9th Annual Meetingof the Oligonucleotide Therapeutics Society in Naples, Italy,running from Sept 25-27, October 1-5 and 6-8, respectively.

In order to participate in the conference call, please dial 1-877 280 2342 (US domestic) and refer toconference ID 2579927. International dial-innumbers and an audio webcast can be accessed under "Events &Presentations" through the Investors & Media section of theProsensa corporate website

About drisapersen

Drisapersen, (previously GSK2402968/PRO051) anantisense oligonucleotide, which induces exon skipping of exon 51,is currently in late stage development for DMD.

GSK obtained an exclusive worldwide license todevelop and commercialize drisapersen from Prosensa in 2009.Drisapersen has been designated orphan drug status in the EU, USand Japan. In June 2013, drisapersen was granted BreakthroughTherapy designation by the US Food and Drug Administration.

For more information regarding the ongoingclinical studies involving drisapersen visit

About DMD

Duchenne Muscular Dystrophy (DMD) is a severelydebilitating childhood neuromuscular disease that affects up to 1in 3,500 live male births. This rare disease is caused by mutationsin the dystrophin gene, resulting in the absence or defect of thedystrophin protein.

Patients suffer from progressive loss of musclefunction due to the absence or defect of the dystrophin protein,often making them wheelchair bound before the age of 12.Respiratory and cardiac muscle can also be affected by the disease.Few patients survive the age of 30.

About exon skipping

The dystrophin gene is the largest gene in thebody, consisting of 79 exons. Exons are small sequences of geneticcode which lead to the manufacture of sections of protein. In DMD,when certain exons are mutated/deleted, the RNA cannot read pastthe fault. This prevents the rest of the exons being read,resulting in a non-functional dystrophin protein and the severesymptoms of DMD.

RNA-based therapeutics, specifically antisenseoligonucleotides inducing exon skipping, are currently indevelopment for DMD. This technology uses synthetic antisenseoligonucleotides to skip an exon next to a deletion and therebycorrect the reading frame, enabling the production of a noveldystrophin protein. Up to 13% of boys with DMD have dystrophin genemutation/deletions amenable to an exon 51 skip.

About Prosensa Holding N.V.

Prosensa (NASDAQ: RNA) is a Dutch biotechnology company engagedin the discovery and development of RNA-modulating therapeutics forthe treatment of genetic disorders. Its primary focus is on rareneuromuscular and neurodegenerative disorders with a large unmetmedical need, including Duchenne muscular dystrophy, myotonicdystrophy and Huntington's disease.

Forward Looking Statements

This press release contains certainforward-looking statements.  All statements, other thanstatements of historical facts, contained in this press release,including statements regarding our strategy, future operations,future financial position, future revenues, projected costs,prospects, plans and objectives of management, are forward-lookingstatements. The words "anticipate," "believe," "estimate,""expect," "intend," "may," "plan," "predict," "project," "target,""potential," "will," "would," "could," "should," "continue," andsimilar expressions are intended to identify forward-lookingstatements, although not all forward-looking statements containthese identifying words. Forward-looking statements in this pressrelease include statements around our exon -skipping drugcandidates and our collaboration with GlaxoSmithKline (GSK). Actualresults may differ materially from those projected or implied insuch forward-looking statements.  Such forward-lookinginformation involves risks and uncertainties that couldsignificantly affect expected results.  These risks anduncertainties are discussed in the Company's SEC filings,including, but not limited to, the Company's Form 6-K containingthis press release and certain sections of the Company'sRegistration Statement on Form F-1. In addition, anyforward-looking statements represent our views only as of today andshould not be relied upon as representing our views as of anysubsequent date. While we may elect to update these forward-lookingstatements at some point in the future, we specifically disclaimany obligation to do so, even if our views change.
CONTACT: Contact:         Prosensa Holding N.V.         Celia Economides, Director IR & Corporate Communications         Phone: +1 917 975 1983         Email:

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