DGAP-News: Prosensa Regains Rights to Drisapersen From GSK and Retains Rights to All Other Programs for the Treatment of Duchenne Muscular Dystrophy (DMD)

| Source: EQS Group AG
DGAP-News: Prosensa Holding N.V. /
Prosensa Regains Rights to Drisapersen From GSK and Retains Rights to
All Other Programs for the Treatment of Duchenne Muscular Dystrophy

13.01.2014 / 14:00


LEIDEN, Netherlands and LONDON, 2014-01-13 14:00 CET (GLOBE NEWSWIRE) --
Prosensa Holding N.V. (Nasdaq:RNA) and GlaxoSmithKline (GSK) today announced
that Prosensa has regained all rights from GSK to drisapersen and will retain
rights to all other programs for the treatment of Duchenne Muscular Dystrophy
(DMD). This transfer of rights represents the termination of the collaboration
agreement between GSK and Prosensa executed in 2009. 

Prosensa will now have the full, unencumbered rights to continue the
development of drisapersen as well as each of its DMD programs. 

The parties have agreed that Prosensa is well suited to continue the
development of all of the DMD programs. Prosensa and GSK have also agreed to
make certain data from the drisapersen studies available in due course to the
scientific community for the purpose of furthering the general understanding of

'We are fully committed to our mission of developing innovative, RNA-based
therapeutics to address unmet medical needs for patients with rare genetic
disorders,' said Hans Schikan, Prosensa's Chief Executive Officer. 'Prosensa is
now in a favorable strategic position to advance the DMD portfolio, which
includes drisapersen and five additional compounds, three of which are
currently in clinical development. We will continue to work closely with
patient groups, investigators, academia and regulators to ensure that we do
everything we can to bring treatments to boys affected by DMD.' 

'We have completed our review and believe that further analysis of drisapersen
data may benefit from being viewed in the context of the body of information
which has been developed by Prosensa through their work on additional
exon-skipping programs. We greatly valued the scientific expertise that
Prosensa provided since our collaboration started in 2009.' said Dr Carlo
Russo, Senior Vice President, Head of GSK Rare Diseases Research & Development.
'We worked closely with Prosensa with the aim of developing new medicines to
help boys with DMD and thanks to the dedication of the boys and their families,
we have gathered the largest clinical dataset related this condition. The value
of this data to the scientific community's understanding of DMD should not be
underestimated, and we would like to thank everyone who participated in the
studies for their contributions and patience as we worked through our

Prosensa's Schikan, added 'GSK has been a valuable development partner, and we
are grateful for the commitment made by the company over the last four years to
develop a disease modifying therapy for this devastating disease. Together we
have been able to progress the largest global clinical program in DMD, and we
have made tremendous progress in understanding the natural history and
epidemiology of this rare and devastating disease.  We look forward to updating
the community with our plans as soon we are in a position to do so.' 

About drisapersen and the clinical development program

Drisapersen, (previously GSK2402968/PRO051), an antisense oligonucleotide which
induces exon skipping of exon 51, is currently in-late stage development for
DMD. In 2009 GSK obtained an exclusive worldwide license from Prosensa to
develop and commercialize drisapersen. Drisapersen has orphan drug status in
the EU, US, Japan and Australia. In June 2013, drisapersen was granted
Breakthrough Therapy designation by the US Food and Drug Administration. 

The overall drisapersen clinical program comprises three double-blind,
placebo-controlled studies (DMD114117, DMD114876 and DMD114044) and two long
term open-label extension studies (DMD114673 and DMD114349). 

For more information regarding the ongoing clinical studies involving
drisapersen visit www.clinicaltrials.gov. 

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, 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 the genetic code past the fault. This prevents the rest of the
exons being read, resulting in a non-functional dystrophin protein and the
severe symptoms of DMD. 

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. 


GSK - one of the world's leading research-based pharmaceutical and healthcare
companies - is committed to improving the quality of human life by enabling
people to do more, feel better and live longer. For further information please
visit www.gsk.com. 

Prosensa Contact:                                              
Prosensa Holding N.V.                                          
Celia Economides, Senior Director IR & Corporate Communications
Phone: +1 917 941 9059                                         
Email: c.economides@prosensa.nl                                

GSK enquiries:                                                                  
UK Media enquiries:     David Mawdsley         +44 (0) 20 8047    (London)      
                        Simon Steel            +44 (0) 20 8047    (London)      
                        David Daley            +44 (0) 20 8047    (London)      
                        Catherine Hartley      +44 (0) 20 8047    (London)      
US Media enquiries:     Stephen Rea            +1 215 751 4394    (Philadelphia)
                        Melinda Stubbee        +1 919 483 2510    (North        
                        Mary Anne Rhyne        +1 919 483 0492    (North        
                        Emily Beamer           +1 215 751 6622    (Philadelphia)
                        Jennifer Armstrong     +1 215 751 5664    (Philadelphia)
Analyst/Investor        Sally Jackson          +44 (0) 20 8047    (London)      
 enquiries:                                     5543                            
                        Kirsty Collins (SRI &  +44 (0) 20 8047    (London)      
                         CG)                    5534                            
                        Tom Curry              + 1 215 751 5419   (Philadelphia)
                        Gary Davies            +44 (0) 20 8047    (London)      
                        James Dodwell          +44 (0) 20 8047    (London)      
                        Jeff McLaughlin        +1 215 751 7002    (Philadelphia)
                        Ziba Shamsi            +44 (0) 20 8047    (London)      
                        Lucy Singah            +44 (0) 20 8047    (London)      

Prosensa 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. 

GSK Cautionary statement regarding forward-looking statements

GSK cautions investors that any forward-looking statements or projections made
by GSK, including those made in this announcement, are subject to risks and
uncertainties that may cause actual results to differ materially from those
projected. Factors that may affect GSK' s operations are described under Item
3.D 'Risk factors' in the company's Annual Report on Form 20-F for 2012. 

GSK Registered in England & Wales:
No. 3888792                       
GSK Registered Office:            
980 Great West Road               
Brentford, Middlesex              
News Source: NASDAQ OMX

End of Corporate News


13.01.2014 Dissemination of a Corporate News, transmitted by DGAP - a
company of EQS Group AG.
The issuer is solely responsible for the content of this announcement.

DGAP's Distribution Services include Regulatory Announcements,
Financial/Corporate News and Press Releases.
Media archive at www.dgap-medientreff.de and www.dgap.de


Language:    English                
Company:     Prosensa Holding N.V.  
ISIN:        NL0010524443           
End of News    DGAP News-Service  
247766 13.01.2014