Jeffrey D. Marrazzo was Spark’s founding CEO, presiding over its creation in 2011 as a research center within the Children’s Hospital of Philadelphia (CHOP). Two years later, Spark was spun out of CHOP’s Center for Cellular and Molecular Therapeutics with a $50-million Series A financing. Spark has grown into a fully integrated, commercial gene therapy company, employing more than 800 people—about half of whom have joined in the past two years or so since Spark was acquired by Roche for $4.8 billion . . .