Sareum Regulatory News (SAR)

23 July 2015

SAREUM HOLDINGS PLC

("Sareum" or "the Company")

CHK1 RESEARCH UPDATE

First description of the CHK1 clinical development candidate published in peer-reviewed journal

New 'chemotherapy booster' could treatlung and pancreatic cancer

Sareum, the specialist cancer drug discovery and development business, is pleased to announce that the discovery and biological characterisation of the CHK1 inhibitor CCT245737 has been published in the peer-reviewed journal, Oncotarget*. CCT245737 is the clinical development candidate discovered in the joint research collaboration between Sareum, The Institute of Cancer Research, London, and Cancer Research Technology.  The intellectual property associated with the project was licensed to the CRT Pioneer Fund (CPF). CPF and Sareum are investing to take the project into Phase I clinical trial before commercialisation.

The journal paper describes how oral delivery of CCT245737 boosts the effectiveness of conventional chemotherapies and could be used to treat lung and pancreatic cancers.

Most chemotherapies work by damaging the DNA of rapidly dividing cells. But in response, cancer cells activate a molecule called CHK1 which delays cell division and gives cancer cells time to repair their damaged DNA.

Scientists continue to believe that blocking CHK1 could stop cancer cells from repairing DNA damage and prevent them from becoming resistant to the cell-killing effects of chemotherapy. The research paper describes the techniques used to assess the method of action of CCT245737 in human cancer cell lines as well as its effect in in-vivo models, and demonstrated that it potently blocked CHK1.

The drug is scheduled to begin first-in-human clinical trials in patients with lung and pancreatic cancers - two cancers with low survival rates that continue to resist currently available treatments.

Professor Ian Collins, Professor of Medicinal Chemistry at The Institute of Cancer Research, London, said: "We're excited that our new CHK1 inhibitor, which was discovered at the ICR in collaboration with Cancer Research UK and Sareum Limited, is progressing towards first-in-human clinical trials. By using CHK1 inhibitors with chemotherapy, we block one of cancer's escape routes and prevent tumours from evading the effects of treatment. We hope that clinical trials of our new drug will show it to be an effective chemotherapy booster in lung and pancreatic cancers, which readily become resistant to current treatments."

The paper also describes how the CHK1 inhibitor could be used to treat B-cell lymphoma when dosed alone, because this cancer type sustains heavy DNA damage during its formation. It is possible that CHK1 inhibitors such as CCT245737 could be used on their own to treat other types of cancer with similar levels of DNA damage. More details of Sareum's work on CHK1 inhibitors were set out in the announcement dated 25 February 2015.

Sareum's CEO, Dr. Tim Mitchell, commented:

"The publication of CCT245737 data in this high-impact journal will bring what we believe to be a best-in-class drug candidate to the attention of our peers and potential licence partners. We are extremely encouraged by the wide ranging potential use for our CHK1 inhibitor either as a single agent or when dosed in combination with other chemotherapies. The preclinical studies are progressing well and we look forward to providing an update with our final results."

* Entitled: The clinical development candidate CCT245737 is an orally active CHK1 inhibitor with preclinical activity in RAS mutant NSCLC and Em-MYC driven B-cell lymphoma (available at: http://www.impactjournals.com/oncotarget/index.php?journal=oncotarget&page=article&op=view&path[]=4919&author-preview=1)

For further information:

- ENDS -

Notes to editors

Sareum is a drug discovery and development company delivering targeted small molecule therapeutics, focusing on cancer and autoimmune disease, for licensing to pharmaceutical and biotechnology companies at the preclinical or early clinical trials stage.

Sareum operates an outsourced research model, working with collaborators (SRI International, the CRT Pioneer Fund and Hebei Medical University Biomedical Engineering Center) and a world-wide network of research providers. Its research pipeline includes two programmes undergoing pre-clinical IND-enabling studies.

SKIL® (Sareum Kinase Inhibitor Library) is Sareum's drug discovery technology platform that has so far produced the Company's Aurora+FLT3, Aurora+ALK, VEGFR-3, FLT3 & TYK2 kinase cancer and autoimmune disease research programmes. SKIL® can also generate drug research programmes against other kinase targets.

Sareum Holdings plc is listed on the AIM market of the London Stock Exchange, trading under the symbol SAR. For further information, please visit www.sareum.co.uk

The Institute of Cancer Research, London, is one of the world's most influential cancer research institutes.

Scientists and clinicians at The Institute of Cancer Research (ICR) are working every day to make a real impact on cancer patients' lives. Through its unique partnership with The Royal Marsden NHS Foundation Trust and 'bench-to-bedside' approach, the ICR is able to create and deliver results in a way that other institutions cannot. Together the two organisations are rated in the top four cancer centres globally.

The ICR has an outstanding record of achievement dating back more than 100 years. It provided the first convincing evidence that DNA damage is the basic cause of cancer, laying the foundation for the now universally accepted idea that cancer is a genetic disease. Today it leads the world at isolating cancer-related genes and discovering new targeted drugs for personalised cancer treatment.

As a college of the University of London, the ICR provides postgraduate higher education of international distinction. It has charitable status and relies on support from partner organisations, charities and the general public.

The ICR's mission is to make the discoveries that defeat cancer. For more information visit http://www.icr.ac.uk