Palo Alto scientist returns to Cambridge as Mosaic Therapeutics CSO
And it is very much a case of back to the future for Dr Stephen Shuttleworth who began his industrial career in Cambridge at Science Park company Chiroscience. Babraham Research Campus-based Mosaic has appointed Dr Shuttleworth as Chief Scientific Officer in succession to Dr Barry Davies, who is retiring at the end of November.
Dr Shuttleworth has been a Venture Partner at Samsara BioCapital, Palo Alto, US since 2019, where his responsibilities include R & D due diligence, new company creation and C-suite level company leadership.
He has over 30 years’ experience as a pharmaceutical scientist, senior executive, entrepreneur and investor. Before Samsara he was CSO, COO and Executive Director for over 10 years at Karus Therapeutics, where he was the founding scientist and R & D director of the company’s two small molecule oncology programmes and raised blue-chip VC investment.
Prior to Karus, he held scientific leadership positions in the UK, US and Canadian biotech industries, notably at Piramed Pharma, Tularik, BioChem Pharma and CRUK.
He clearly brings significant scientific expertise in small molecule cancer therapeutics R & D and medicinal chemistry. He has directed multiple small molecule therapeutics research programmes, primarily in cancer, and also in immunology and inflammation, metabolic disorders and infectious diseases.
Of note, he led the design, research and preclinical development of three small molecule cancer therapeutics, all completing phase I clinical studies: Pictilisib (pan-class I PI3K), KA2237/CVL-237 (selective PI3K-b/d), and KA2507 (HDAC6).
Thomas Fuchs, CEO, Mosaic Therapeutics said: “We are excited to welcome Stephen to the Mosaic leadership team. He is a seasoned scientific leader and biotech investor, and I look forward to working with him as we bring our lead products into the clinic and work to build out our pipeline of precision oncology programmes.
“We also thank Barry for his leadership and significant contributions to the Mosaic team, in particular guiding our platform and pipeline development, and wish him all the best in his well-deserved retirement.”
Mosaic is applying its advanced experimental and computational platform to identify oncology combinations that have synergistic activity in biomarker-defined patient populations. The company’s pipeline of combination programmes is anchored by ASTX029, an ERK1/2 inhibitor, and ASTX295, an MDM2 antagonist, both in-licensed from Astex Pharmaceuticals in April 20251. Mosaic’s first clinical combination study is expected to start in 2026.
Dr Shuttleworth said: “Mosaic’s Synergistic Precision approach to the discovery of biomarker-defined, targeted therapies is truly innovative and I look forward to working alongside the team to realise the full potential of the Company’s discovery platform and capabilities.”
