Summit Corporation Announces Positive Phase 1 Trial Results for SMT C1100 for Treatment of Duchenne Muscular Dystrophy

Oxford, UK, 10 October 2012 – Summit (AIM: SUMM), a UK drug discovery company, announces positive top-line results from a Phase 1 clinical trial of SMT C1100 for the treatment of Duchenne Muscular Dystrophy (‘DMD’), a fatal muscle wasting disease for which there is currently no cure. SMT C1100, an oral small molecule, is a potential disease modifying drug that works to increase or upregulate the amount of a naturally occurring protein called utrophin. These data will be presented at the 17th Annual Congress of the World Muscle Society, 9-13 October 2012, Perth Australia.

The Phase 1 dose-escalating trial was conducted in healthy volunteers and evaluated a new aqueous formulation of SMT C1100. The trial met its primary endpoints with results showing the formulation to be safe and well tolerated at all doses. Importantly, the new formulation also demonstrated improved levels of bioavailability (absorption) of the drug that were above those anticipated to be needed to achieve clinical efficacy. These results are strongly supportive for the progression of SMT C1100 into patient clinical trials.

“The positive outcome from this Phase 1 trial is a significant step forward for DMD and our utrophin upregulator drug SMT C1100,” commented Glyn Edwards, Chief Executive Officer of Summit. “Utrophin upregulation is an important mechanism for treating DMD as it is expected to have broad applicability for all patients regardless of the specific genetic fault causing their disease. We are highly encouraged that the new formulation of SMT C1100 shows improved bioavailability as we believe it supports the progression of this potential breakthrough treatment into DMD patient clinical trials.”

The double-blind, placebo-controlled trial examined single and multiple ascending oral doses of a nanoparticle aqueous suspension formulation of SMT C1100 in a total of 48 healthy volunteers. When single doses were increased from 50mg/kg up to 400mg/kg, SMT C1100 blood plasma levels were increased for several hours above those required to give a 50% increase in utrophin levels in vitro measured in cells taken from DMD patients. In addition, the new formulation resulted in higher blood plasma concentrations of SMT C1100 when compared with results from a previous Phase 1 healthy volunteer study that used a different formulation. Analysis of the multiple ascending dose groups remains on-going and results are expected to be reported later this year.

A copy of the presentation being given at the World Muscle Society Congress will be available from Summit’s website, www.summitplc.com.

The Phase 1 trial has been supported by a group of US DMD foundations: the Muscular Dystrophy Association, Charley’s Fund, Cure Duchenne, the Foundation to Eradicate Duchenne, Nash Avery Foundation and Parent Project Muscular Dystrophy.

About SMT C1100

SMT C1100 is designed to upregulate and maintain the production of utrophin. Utrophin is a protein that is highly expressed in foetal and regenerating muscle but decreases as the muscle fibre mature and is eventually replaced by dystrophin, a similar protein that maintains the integrity and healthy function of muscles. Patients with DMD are unable to make dystrophin, resulting in muscle fibre degeneration. However, if utrophin is continually expressed in the mature fibre, it can functionally replace dystrophin and is expected to overcome the deficit in patients with DMD. This approach is expected to be a universal treatment for all DMD patients regardless of whether the disease was caused by an inherited or spontaneous mutation. Summit has demonstrated in non-clinical efficacy studies that SMT C1100 is capable of increasing utrophin to restore and maintain the healthy function of muscles including the heart and diaphragm. SMT C1100 has been granted orphan drug status in Europe and the US.

About Summit

Summit is an Oxford, UK based drug discovery Company targeting high-value areas of unmet medical need including Duchenne Muscular Dystrophy and C. difficile infection. Summit is listed on the AIM market of the London Stock Exchange and trades under the ticker symbol SUMM. Further information is available at www.summitplc.com.

For more information, please contact:

Summit

Glyn Edwards / Richard Pye

Tel: +44 (0)1235 443 951

Singer Capital Markets

(Nominated Adviser and Joint broker)

Shaun Dobson / Jenny Wyllie

Tel: +44 (0)203 205 7500

Hybridan LLP

(Joint broker)

Claire Louise Noyce / Deepak Reddy

Tel: +44 (0)207 947 4350

Peckwater PR

(Financial public relations, UK)

Tarquin Edwards

Tel: +44 (0)7879 458 364

tarquin.edwards@peckwaterpr.co.uk

MacDougall Biomedical Communications

(U.S. media contact)

Michelle Avery

Tel: +1 781-235-3060

Forward Looking Statements

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