Stephen joined Karus as CSO in 2008, and in 2017 was appointed COO. He is the founding scientist of the company’s PI3K-p110β/δ and HDAC6 programs. Previously, he held R&D leadership positions in UK and North American biotech, working in several disease areas across multiple therapeutic targets, notably at Chiroscience, BiochemPharma, Tularik, CRUK and Piramed. At Piramed, he directed the PI3K programs, designing and leading the preclinical development of Pictilisib, partnered with Genentech and subsequently taken into Phase II by Roche, who acquired Piramed for $160M in 2008. He obtained his BSc and PhD in Chemistry from the University of Liverpool. He is a recognized opinion leader in the PI3K and HDAC arenas, has published extensively, and been an invited speaker at multiple international conferences. In 2007 he was appointed a Fellow of the Royal Society of Chemistry, and in 2014 an Honorary Professor (Molecular & Clinical Cancer Sciences, School of Medical Science) at the University of Manchester.