10 September 2018

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


("Sareum" or "the Company")

Sareum reaches preclinical milestone in TYK2/JAK1 inhibitor programme - Potent, selective small molecule inhibitor of TYK2/JAK1 selected for further development as a potential treatment for autoimmune diseases

Sareum Holdings plc (AIM: SAR), the specialist small molecule drug development company, announces it has made the formal selection of a development candidate from its TYK2 inhibitor programme to advance through preclinical development as a potential new treatment for autoimmune diseases.

The candidate molecule, SDC-1801, demonstrated high selectivity for TYK2 and JAK1 kinases (particularly over related JAK2 and JAK3), compelling activity in disease models of psoriasis and rheumatoid arthritis, the potential for once-daily oral dosing and a good early safety profile. Closely related molecules, including SAR-20347, have also shown good activity in models of inflammatory bowel disease and systemic lupus erythematosus (lupus). These attributes strongly support the progression of SDC-1801 into preclinical development and, pending satisfactory progress, advancement into human clinical trials, which could begin in 2020.

The preclinical development candidate SDC-1801 was nominated from a novel series of compounds designed and identified by Sareum following a rigorous selection process. The company is also completing its assessment of further dual TYK2/JAK1 inhibitors for the potential treatment of certain cancers and/or as a back-up to SDC-1801 and expects to nominate this candidate in the near future.

TYK2 and JAK1 are members of the Janus Kinase (JAK) family of protein kinase enzymes with roles in pro-inflammatory responses in autoimmune diseases and tumour cell proliferation in certain cancers. Members of the JAK family are the targets of several marketed and clinical-stage drugs for cancer and autoimmune diseases, although there are currently no marketed products specifically targeting TYK2. 

Dr Tim Mitchell, CEO of Sareum, commented: “TYK2 and JAK1 have emerged in recent years as important targets for new drugs with potential to treat a broad range of autoimmune diseases. This has naturally led to some serious interest from the major pharmaceutical companies, including  Pfizer, Bristol-Myers Squibb and Celgene having their own clinical and preclinical programmes in this area. With SDC-1801, we believe we are entering this space with a strong candidate that exhibits potentially best-in-class features. We intend to focus our resources on advancing SDC-1801 through preclinical development and into clinical trials over the next 18 months. At the same time, we will continue our discussions with potential licence partners for this exciting drug candidate.”

Sareum has an ongoing co-development agreement with SRI International (Menlo Park, CA, USA) to develop TYK2 inhibitors in autoimmune diseases. Sareum retains commercialisation rights for these and other TYK2 inhibitors with profiles optimised for oncology indications.


For further information, please contact: 

Sareum Holdings plc


Tim Mitchell

 01223 497 700

WH Ireland Limited (Nominated Adviser)

Chris Fielding / James Sinclair-Ford

 020 7220 1666

Hybridan LLP (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 development company delivering targeted small molecule therapeutics, focusing on cancer and autoimmune disease. The Company generates value through licensing its candidates to international pharmaceutical and biotechnology companies at the preclinical or early clinical trials stage.

Sareum’s leading clinical-stage programme, SRA737, a novel Checkpoint kinase 1 (Chk1) inhibitor licensed to NASDAQ-listed Sierra Oncology, is in Phase 2 clinical trials targeting ovarian and other 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 internal programmes focused on distinct dual tyrosine kinase 2 (TYK2) /Janus kinase 1 (JAK1) inhibitors through preclinical development as therapies for autoimmune diseases and cancers. TYK2 and JAK1 have roles in pro-inflammatory responses in autoimmune diseases (e.g. psoriasis, rheumatoid arthritis, inflammatory bowel diseases and lupus) and tumour cell proliferation in certain cancers (e.g. T-cell acute lymphoblastic leukaemia and some solid tumours). The Company is targeting first human clinical trials in each indication in 2020.

The Company also has an Aurora+FLT3 inhibitor targeting haematological cancers, which is in preclinical development.

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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