Summit Therapeutics to Present New Preclinical Data on

• Treatment with SMT C1100 and SMT022357 results in increased utrophin along the length of muscle fibers leading to disease reduction in DMD models

OXFORD, United Kingdom, June 19, 2015 (GLOBE NEWSWIRE) -- Summit Therapeutics plc (AIM:SUMM) (Nasdaq: SMMT ), the drug discovery and development company advancing therapies for Duchenne muscular dystrophy ('DMD') and C. difficile infection, announces new preclinical data on its lead utrophin modulator SMT C1100 and second generation compound SMT022357, which are in development for the treatment of all patients with DMD. These data are being reported at the annual Parent Project Muscular Dystrophy ('PPMD') Connect conference being held between 18-21 June in Washington, DC.

The studies conducted in an in vivo model of DMD showed that after daily oral treatment with either SMT C1100 or SMT022357, utrophin was localized along the entire length of muscle fiber membrane (sarcolemma). These data are supportive of the utrophin modulation mechanism as they suggest that the small molecule compounds are increasing utrophin transcription in myonuclei along the entire length of muscle fibers. The studies also showed that the dystrophin associated protein complex ('DAPC') was restored with β-dystroglycan and β-dystrobrevin, both members of the DAPC, being expressed at the membrane of all fibers. The DAPC plays a structural role in muscle fibers and it is significantly reduced in membranes of muscle fibers in boys with DMD.

"The ability to maintain utrophin along the entire length of muscle fibers, combined with the restoration of the DAPC, is essential if this approach is to reduce the progression of this devastating muscle disease. These data strongly support utrophin modulation as a valuable mechanism to treat DMD," said Professor Dame Kay E. Davies of the University of Oxford . "There is tremendous therapeutic potential for utrophin modulation in DMD given there is no approved therapy applicable for all patients with DMD with many of the other clinical candidates focused on disease modifying approaches restricted to sub-populations of specific dystrophin mutations."

Utrophin is structurally and functionally similar to dystrophin, the protein which is absent in boys with DMD. Utrophin is normally expressed by everyone during muscle development and repair. By modifying utrophin expression to be constantly produced in the muscles of boys with DMD, this potentially disease-modifying approach has the potential to circumvent the need for dystrophin in all patients with this disease. Summit is currently evaluating SMT C1100, a first-generation utrophin modulator, in a Phase 1b clinical study.

A copy of the presentation to be given at the PPMD Connect Conference is now available from the Company's website, www.summitplc.com .

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About DMD and Utrophin Modulation

DMD is a progressive muscle wasting disease that affects around 50,000 boys in the developed world. The disease is caused by different genetic faults in the gene that encodes dystrophin, a protein that is essential for the healthy function of all muscles. There is currently no cure for DMD and life expectancy is into the late twenties. Utrophin protein is functionally and structurally similar to dystrophin. In preclinical studies, the continued expression of utrophin has meaningful, positive effect on muscle performance. Utrophin modulation has the potential to slow down or even stop the progression of DMD, regardless of the underlying dystrophin mutation. It is also expected that utrophin modulation could potentially be complementary to other therapeutic approaches for DMD.

About Summit Therapeutics

Summit is a biopharmaceutical company focused on the discovery, development and commercialization of novel medicines for indications for which there are no existing or only inadequate therapies. Summit is conducting clinical programs focused on the genetic disease Duchenne muscular dystrophy and the infectious disease C. difficile infection. Further information is available at www.summitplc.com and Summit can be followed on Twitter ( @summitplc ).

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