10 May 2018

 This announcement contains inside information for the purposes of Article 7 of Regulation 596/2014


("Sareum" or "the Company")

 Sareum notes that Sierra Oncology has confirmed the start of the cohort expansion Phase 2 trial evaluating SRA737 plus gemcitabine in genetically defined cancer patients

Sareum Holdings plc (AIM: SAR), the specialist cancer drug discovery and development business, notes that Sierra Oncology, the licence holder advancing clinical cancer candidate SRA737, today reported its financial and operational results for the first quarter ended 31 March 2018.

 In this report, Sierra Oncology confirmed that it has started the Cohort Expansion phase of the SRA737-02 Phase 1/2 Low Dose Gemcitabine Combination Trial. This Phase 2 element will explore the preliminary efficacy of SRA737 plus low dose gemcitabine (LDG) in prospectively enrolled genetically-defined patients with tumours that harbour genomic alterations hypothesised to confer sensitivity to Chk1 inhibition via synthetic lethality.

 Sierra Oncology announced in its Program Update on 27 February 2018 that significant progress has been made in the LDG Combo Dose Escalation Phase 1, and the combination regimen has been very well-tolerated.  In addition, the Cohort Expansion phase had been expanded to target enrolment of 80 genetically-selected patients across four indications, including advanced or metastatic:

•             urothelial carcinoma;

•             small cell lung cancer (SCLC);

•             soft tissue sarcoma;

•             cervical/anogenital cancer

A further update on the study is expected to be provided in the fourth quarter of 2018.

In its first quarter report, Sierra reiterated the status of its other clinical development programmes with SRA737, which as described in the 27 February 2018 Program Update are as follows:

1)      SRA737-01 Phase 1/2 Monotherapy Trial:

  1. Dose Escalation Phase 1 complete and the Cohort Expansion Phase 2 portion is enrolling genetically-defined patients into six indication specific cohorts – the size of these cohorts has been expanded to 20 patients per cohort and the number of clinical centres in the UK increased from three to a planned 15 centres. 20 patients were enrolled as of the date of the February update.
  2. A new indication was added – CCNE1-driven high grade serous ovarian cancer (HGSOC) – based on preclinical data demonstrating that SRA737 has significant anti-tumour activity and a profound survival benefit in CCNE1-driven HGSOC preclinical models. Promising data was presented in a late-breaking poster at the American Association of Cancer Research (AACR) annual meeting in April.
  3. The Cohort Expansion Phase 2 portion of the study is expected to report preliminary clinical data in the fourth quarter of 2018.

2)      SRA737 PARPi Combination Program

  1. A combination trial of SRA737 with niraparib, an orally administered poly ADP-ribose polymerase (PARP) inhibitor in patients with prostate cancer is targeted to start in the fourth quarter of 2018.
  2. The multi-centre Phase 1b/2 study is to be led by Professor Johann de Bono at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust.
  3. Promising data demonstrating the synergy of SRA737 combined with niraparib in killing cancer cells and preventing PARPi resistance was also presented at the AACR meeting in April.

3)      SRA737 Combination with Immuno-Oncology

  1. During its Program Update in February, Sierra presented preclinical data providing evidence of synergy between SRA737 and immune checkpoint blockade. Sierra is currently designing a clinical study for this combination, which potentially could be submitted to regulatory authorities in the fourth quarter of 2018.     

Dr Tim Mitchell, CEO of Sareum commented: “We are very pleased with the progress that Sierra Oncology has made across its clinical trials and future plans with SRA737. Sierra’s clinical development strategy to target genetically defined patients is an approach that is gaining increasing confidence throughout the industry as it selects for patients who might best respond to a particular treatment regimen while potentially shortening the overall development time for novel cancer therapies such as SRA737.”

The full announcement can be found at www.sierraoncology.com.

For further information, please contact: 

Sareum Holdings plc


Tim Mitchell

01223 497 700

WH Ireland Limited (Nominated Adviser and Co-Broker)

Chris Fielding / James Sinclair-Ford

020 7220 1666

Hybridan LLP (Co-Broker)


Claire Noyce

020 3764 2341

Citigate Dewe Rogerson (Media enquiries)


 Shabnam Bashir/ Mark Swallow/ David Dible

 020 7282 9571

Notes for editors: 

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

Its most advanced programme, SRA737, is a novel Checkpoint kinase 1 (Chk1) inhibitor licensed to NASDAQ-listed Sierra Oncology and in clinical trials targeting a range of advanced cancers. The key role of Chk1 in cancer cell replication and DNA damage repair suggests that SRA737 may have broad application as a targeted therapy in combination with other oncology and immune-oncology drugs in genetically defined patients.

Sareum is also advancing programmes to develop novel tyrosine kinase 2 (TYK2) inhibitors in autoimmune diseases and cancers, and Aurora+FLT3 inhibitors in haematological cancers, which are in the IND-enabling preclinical and lead optimisation stages.

 The Company’s drug discovery technology platform (SKIL® - Sareum Kinase Inhibitor Library) is being applied to 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 ticker SAR. For further information, please visit www.sareum.co.uk

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