PSIOXUS LAUNCHES PHASE I/II CLINICAL TRIAL OF ONCOLYTIC VACCINE WITH DOSING OF PATIENT WITH METASTATIC CANCER

PSIOXUS LAUNCHES PHASE I/II CLINICAL TRIAL OF ONCOLYTIC VACCINE WITH DOSING OF PATIENT WITH METASTATIC CANCER

'Evolve' Study Will Assess Safety and Tolerability of Unique Anti-Cancer Agent, ColoAd1

OXFORD, UK – 26 September 2012 – PsiOxus Therapeutics, Ltd. (PsiOxus) has treated the first patient in its phase I/II clinical trial of ColoAd1 for the treatment of metastatic solid tumours. The Evolve (EValuating OncoLytic Vaccine Efficacy) study is the first clinical trial of the systemically available oncolytic vaccine ColoAd1, a highly potent, broad-spectrum, anti- cancer therapeutic capable of destroying tumour cells at minute concentrations.

PsiOxus will conduct the multinational Phase I/II study at up to 20 sites in Europe. Regulatory approvals to proceed with the study have so far been received for the UK, Spain and Belgium. The safety, biological activity and efficacy of ColoAd1 will be evaluated in 126 patients, with initial results expected by the end of 2013. The first patient was dosed this week at a site in Belgium.

ColoAd1 was developed using the evolutionary principle of natural selection to generate an oncolytic vaccine with optimal anti-cancer properties. The vaccine is injected into the bloodstream, and is then delivered to the cancer sites, where it replicates inside of cancer cells and kills them. Each infected cell produces thousands of new copies of ColoAd1, which spread to nearby cancer cells and kills them, as well, while ignoring normal cells. The approach represents a new generation of so-called "self-amplifying" cancer therapy that has the effect of killing tumors and acting as a cancer vaccine.

Dr John Beadle, CEO of PsiOxus, commented: "The Evolve study is a major milestone for both PsiOxus and ColoAd1 as we test a new form of anti-cancer agent with greatly improved selectivity for tumor cells in humans for the first time. While there remains much work to be done, the Evolve study could forge a path to a new treatment option for patients with metastatic
cancer. The advantage of this type of cancer vaccine is that the immune response will be specific for each patient's own personal cancer."

The Principal Investigator and Independent Oncologist of the Evolve Study is Professor Josep Tabernero from the Vall d'Hebron University Hospital in Barcelona. The trial is funded from the recent £22 million (US$34 million) investment made by Imperial Innovations, SROne, Lundbeckfond Ventures and Invesco Perpetual, as well as £1.8 million of support from the Wellcome Trust. The Phase I component is currently recruiting patients with solid tumours and who have no further conventional treatment options open to them. This initial phase aims to establish a safe dose schedule for ColoAd1 in cancer patients. The Phase II component will then recruit patients with metastatic colorectal cancer and who have already received standard first- line therapy. The primary endpoint of the Phase II component is Progression Free Survival (PFS) when compared to patients receiving standard therapy alone. Secondary endpoints include response rates and overall survival.

ColoAd1 is highly effective at selectively targeting and killing cancer cells while having little or no activity on normal tissue. ColoAd1 has been shown to be up to 1,200 times more potent at killing human cancer cells than non-cancerous human cells. Standard chemotherapy agents are much less selective for cancer cells, accounting for the often-severe side effects of chemotherapy. Importantly, scientists in Professor Len Seymour's laboratory at the University of Oxford, UK have shown that ColoAd1 survives very well in human blood.

According to Prof Seymour: "This characteristic is fairly unique to ColoAd1 and is not shared with many other viruses. This means that ColoAd1 can be delivered efficiently by intravenous infusion, which is a significant advantage over many other oncolytic viruses in development. The blood stream will carry the ColoAd1 to all metastatic cancer sites in the body, where they can self-amplify at the site of action, making this a very exciting step forward in the field."

The initial target indications for ColoAd1 are metastatic colorectal cancer and primary hepatic cellular carcinoma. These are both exceptionally large market segments with significant unmet medical need. The incidence of colorectal cancer is forecast to reach nearly 500,000 cases by 2018. Primary hepatic cellular carcinoma is the third leading cause of cancer mortality worldwide, and remains a significant unmet medical need with few effective treatment options.

About PsiOxus Therapeutics, Ltd.
PsiOxus Therapeutics is an Oxford, UK-based development stage biotechnology company using non-traditional approaches to develop novel therapeutics that address cancer and other clinically unmet diseases. ColoAd1 is an oncolytic vaccine for the systemic treatment of metastatic cancer, which has demonstrated exceptional anti-cancer properties in late pre-clinical development and is now in phase I clinical development. MT-102 is a dual action Anabolic Catabolic Transforming Agent (ACTA) in phase II clinical development for the treatment of cachexia and sarcopenia. The Company is also developing treatments based upon the research phase vaccine platform PolySTAR, which combines recombinant viral vectors with polymers to shield them from the immune system, and the research phase adjuvant and immunotherapeutic platform PolyMAP, which combines polymers with synthetic adjuvants to significantly enhance the effectiveness of vaccines.

Dr John Beadle is CEO of PsiOxus. Dr Beadle was previously a co-founder of PowderMed, which was sold to Pfizer, Inc. for more than $300 million in 2006. Dr Michael Moore, the former CEO of Piramed, which was acquired by Roche in 2008, serves as Chairman of the Board of Directors.

PsiOxus is advised by a distinguished Scientific Advisory Board that includes Prof Len Seymour (Chair of Gene Medicine at Oxford University and Secretary General of the European Society for Gene and Stem Cell Therapy), Dr Kerry Fisher (an internationally-recognized specialist in molecular medicine, also of Oxford University), Prof Andrew Coats (Norwich Research Park Professor-at-Large, University of East Anglia), and Prof Stefan Anker (Professor of Cardiology and Cachexia Research at Charité Medical School, Berlin and President of the Society on Sarcopenia, Cachexia and Wasting Diseases).