Prosensa to Host Conference Call to Discuss Recent Drisapersen Data Presentations

Prosensa to Host Conference Call to Discuss Recent Drisapersen Data

Conference call and live webcast scheduled for 11:00 a.m. ET (5:00 p.m. CET)
on Tuesday, October 8, 2013

Leiden, The Netherlands, Oct. 3, 2013 (GLOBE NEWSWIRE) -- Prosensa Holding
N.V. (NASDAQ: RNA), the Dutch biopharmaceutical company focusing on
RNA-modulating therapeutics for rare diseases with 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 discuss recently-presented data on drisapersen, an investigational
antisense oligonucleotide, for the treatment of Duchenne Muscular Dystrophy
(DMD) patients with an amenable mutation, which is exclusively licensed to
GlaxoSmithKline (GSK).

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

The data were presented at the DIA/FDA Oligonucleotide based Therapeutics
Conference in Washington DC, the 18th World Muscle Society Congress in
Asilomar, California and the 9th Annual Meeting of 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 to conference ID 2579927. International dial-in numbers
and an audio webcast can be accessed under "Events & Presentations" through
the Investors & Media section of the Prosensa corporate website

About drisapersen

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

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

For  more  information  regarding  the  ongoing  clinical  studies   involving 
drisapersen visit

About DMD

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

Patients suffer from progressive loss of muscle function 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 the body, consisting of 79  exons. 
Exons are small  sequences of genetic  code which lead  to the manufacture  of 
sections of protein. In DMD, when  certain exons are mutated/deleted, the  RNA 
cannot read past the fault.  This prevents the rest  of the exons being  read, 
resulting in a non-functional  dystrophin protein and  the severe symptoms  of 

RNA-based therapeutics, specifically antisense oligonucleotides inducing  exon 
skipping, are currently in development for DMD. This technology uses synthetic
antisense oligonucleotides to  skip an  exon next  to a  deletion and  thereby 
correct the  reading frame,  enabling  the production  of a  novel  dystrophin 
protein. Up to 13%  of boys with DMD  have dystrophin gene  mutation/deletions 
amenable to an exon 51 skip.

About Prosensa Holding N.V.

Prosensa (NASDAQ: RNA) is a Dutch biotechnology company engaged in the
discovery and development of RNA-modulating therapeutics for the treatment of
genetic disorders. Its primary focus is on rare neuromuscular and
neurodegenerative disorders with a large unmet medical need, including
Duchenne muscular dystrophy, myotonic dystrophy and Huntington's disease.

Forward Looking Statements

This  press  release   contains  certain   forward-looking  statements.   All 
statements, other than statements 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-looking  statements.  The  words 
"anticipate,"  "believe,"  "estimate,"  "expect,"  "intend,"  "may,"   "plan," 
"predict,"  "project,"  "target,"   "potential,"  "will,"  "would,"   "could," 
"should,"  "continue,"  and  similar  expressions  are  intended  to  identify 
forward-looking  statements,  although  not  all  forward-looking   statements 
contain these  identifying words.  Forward-looking  statements in  this  press 
release include statements around our  exon -skipping drug candidates and  our 
collaboration with GlaxoSmithKline (GSK). Actual results may differ materially
from those  projected or  implied in  such forward-looking  statements.  Such 
forward-looking  information  involves  risks  and  uncertainties  that  could 
significantly affect  expected results.  These  risks and  uncertainties  are 
discussed in the  Company's SEC filings,  including, but not  limited to,  the 
Company's Form 6-K containing this press  release and certain sections of  the 
Company's Registration Statement on Form F-1. In addition, any forward-looking
statements represent our views only as of today and should not be relied  upon 
as representing our views  as of any  subsequent date. While  we may elect  to 
update these  forward-looking  statements at  some  point in  the  future,  we 
specifically disclaim any 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

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