Thomas Koestler

Thomas P. Koestler, Ph.D., is a veteran pharmaceutical R&D executive with roughly 30–35 years in the industry, during which he has reportedly guided more than 80 programs to FDA submission and approval, including more than 30 new molecular entities and biologics. He holds a B.S. in biology from Daemen College (Amherst, N.Y.) and a Ph.D. in medicine and pathology from the State University of New York at Buffalo / Roswell Park Memorial Institute.

Koestler built his career inside large pharma R&D organizations. He served as senior vice president and global head of drug regulatory affairs, compliance assurance, clinical safety and epidemiology at Novartis; then as senior vice president and head of global regulatory affairs at Pharmacia Corporation (approximately 2001–2003); and from 2006 to 2009 as executive vice president of Schering Corporation and president of the Schering-Plough Research Institute (SPRI), Schering-Plough's R&D arm, until the company's merger with Merck.

Since February 2010, Koestler has served as an executive director of Vatera Holdings LLC, the manager of Vatera Healthcare Partners LLC. Vatera was founded in 2007 by the late Michael Jaharis (founder of Key Pharmaceuticals and Kos Pharmaceuticals) and invests in biopharmaceutical companies developing best-in-class therapies for unmet medical needs.

Beyond his investing role, Koestler is an active biopharma board member and advisor. He joined the board of Melinta Therapeutics in November 2012 and was elected chairman in April 2013, and has held board or advisory roles with Momenta Pharmaceuticals, ImmusanT, Arisaph Pharmaceuticals, Edgemont Pharmaceuticals, Novo Nordisk A/S, and Allergan (scientific advisor). In August 2022 he was named to the newly established Kallyope Clinical Development Advisory Board.

• Invests through Vatera Healthcare Partners, the venture/PE arm of a New York family-office advisor, focused exclusively on biopharmaceuticals and life sciences.
• Backs companies with "differentiated assets and/or business models" that address significant unmet medical needs, taking active, hands-on positions rather than passive minority stakes.
• Works across the capital structure and development stages — from earlier venture rounds (e.g., Series C) through growth equity and post-IPO commitments.
• Brings deep R&D, regulatory, and clinical-development operating expertise (Novartis, Pharmacia, Schering-Plough) to portfolio companies, frequently taking board chairmanships.
• Therapeutic interest spans anti-infectives/antibiotic resistance, respiratory disease, and autoimmune/specialty conditions, mirroring the firm's flagship deals.