After 30 formal meetings and dozens of informal conversations with former colleagues, industry veteran Jim Burns was still euphoric on the final day of the 35th Annual J.P. Morgan (JPM) Healthcare Conference – his first. After nearly 30 years at Genzyme Corp. and parent company Sanofi SA, where he most recently headed the big pharma's North American R&D hub, Burns came to San Francisco with a new gig as president and CEO of start-up Casebia Therapeutics.