Davis Polk advised the representative of the underwriters in connection with the $181 million public offering of 4,025,000 shares of common stock of Spark Therapeutics, Inc. (“Spark”), which included 3,025,000 shares sold by the company and 1,000,000 shares sold by The Children’s Hospital of Philadelphia Foundation (“CHOP”). The common stock is listed on the NASDAQ Global Select Market under the symbol “ONCE.”

Based in Philadelphia, Pennsylvania, Spark is a gene therapy leader seeking to transform the lives of patients suffering from debilitating genetic diseases by developing one-time, life-altering treatments. Spark’s initial focus is on treating rare diseases where no, or only palliative, therapies exist. Spark’s most advanced product candidate, SPK-RPE65, which has received both breakthrough therapy and orphan product designation, has reported positive top-line results from a pivotal Phase 3 clinical trial for the treatment of rare blinding conditions. Spark’s validated gene therapy platform is being applied to a range of clinical and preclinical programs addressing serious genetic diseases, including inherited retinal dystrophies, hematologic disorders and neurodegenerative diseases. Spark builds on two decades of research, development and manufacturing at The Children’s Hospital of Philadelphia, including human trials conducted across diverse therapeutic areas and routes of administration.

The Davis Polk corporate team included partner Richard D. Truesdell Jr. and associates Julia Danforth, Julian Veshi and Cameron C. Lewis. The intellectual property and technology team included counsel David R. Bauer and associate Bonnie Chen. Counsel Marcie A. Goldstein provided FINRA advice. The tax team included partner Rachel D. Kleinberg and associate Dao Fu. Members of the Davis Polk team are based in the New York and Northern California offices.