Langer has held executive, operating, and governance roles in start-up and established biotechnology and pharmaceutical companies, for more than three decades. Under his leadership, those organizations developed and/or commercialized more than 60 products. Having begun as a clinician—serving as chief resident at Yale University School of Medicine and a clinical fellow at Harvard Medical School and the National Institutes of Health—Langer went on to hold significant R&D and marketing roles at Eli Lilly, Abbott, Searle, and GlaxoSmithKline (where he was a senior vice president for research and development), and to be a managing partner of Phoenix IP Ventures. He has also been a clinical professor of psychiatry at Georgetown University School of Medicine since 2003. In addition, Langer has served on more than two dozen company boards and been a member of governance or advisory boards at Columbia University, Georgetown University, and Harvard Law School. Before joining the Whitehead Institute board in 2019, he was a member of its Finance Committee. He continues to serve on that committee, as well as the Audit and Risk Committee.