Dr. Sinclair has developed and managed healthcare companies for over forty years. He is Executive Chairman of Advanced Oncotherapy, PLC. He has served on the Board of Overseers (emeritus) of the Tufts University School of Medicine since 1993. In 1994 he founded U.S.-based Atlantic Medical Management LLP, which managed the New York based healthcare venture fund, Atlantic Medical Capital LP, where he served as Chairman until 2001. As Executive Chairman of Lifetime Corporation, which he founded, he was instrumental in growing its KQC subsidiary from one office in Nashville to a business with a turnover of $1 billion between 1982 and 1993. He acted as President (International) of INA Healthcare Group (subsequently CIGNA) and its Hospital Affiliates Inc. subsidiary between 1979 and 1982. His transition to business came when he founded and acted as Chief Executive of Nestor PLC in 1971. As a physician specializing in psychiatry, he began his medical career at Middlesex Hospital in London in 1967.