Brian P. O'Sullivan

Brian P. O'Sullivan, MD is a Professor of Pediatrics at the Geisel School of Medicine, Dartmouth, where he serves as Section Chief of Pediatric Pulmonary and Pediatric Program Director of the New Hampshire Cystic Fibrosis Center. His clinical practice spans Dartmouth Hitchcock Clinics in Manchester and Dartmouth Hitchcock Medical Center in Lebanon, NH.

His research focuses primarily on cystic fibrosis and pediatric pulmonology, with particular expertise in CFTR modulator therapies, respiratory infections in cystic fibrosis patients, and nontuberculous mycobacteria disease. Dr. O'Sullivan leads multiple clinical trials investigating novel treatments and diagnostic approaches for cystic fibrosis patients across various age groups.

His clinical trial portfolio demonstrates significant expertise in CFTR modulator therapies, including VX-121, VX-659, VX-445, and other compounds targeting the underlying genetic defects in cystic fibrosis. His research also addresses complications of cystic fibrosis such as chronic Pseudomonas aeruginosa infections and sinonasal disease.

• 2025 Top Doctor (named by Castle Connolly, published by New Hampshire Magazine)

Dr. O'Sullivan has contributed to the Cystic Fibrosis Foundation Patient Registry and leads studies evaluating long-term safety and efficacy of various CFTR modulator therapies. His work bridges clinical practice with research to improve outcomes for children and adults with cystic fibrosis across Northern New England.