Siobhan O'Brien

Siobhan O'Brien is a highly experienced scientist with a focus on biomarkers and imaging in the field of drug development. Currently serving as Principal Scientist at Vertex Pharmaceuticals since January 2019, O'Brien leads biomarker initiatives for Cystic Fibrosis small molecule programs and has extensive experience in clinical studies across various phases. Prior roles include significant contributions in oncology research at Prolong Pharmaceuticals, where O'Brien was biology lead for a pegylated protein therapeutic and managed key biomarker studies. O'Brien's background includes postdoctoral research at Pfizer and UMass Medical School, with a Ph.D. in Biomedical Sciences and a solid foundation in biochemistry. Complementing formal education, O'Brien has pursued additional training in clinical research management.