PHILADELPHIA, Dec. 14, 2015 (GLOBE NEWSWIRE) -- Spark Therapeutics, Inc. (NASDAQ:ONCE) announced today that it has been selected by NASDAQ for addition to the NASDAQ Biotechnology Index ® (Nasdaq:NBI). The annual re-ranking of the NASDAQ Biotechnology Index will become effective upon market open on Monday, December 21, 2015. The NASDAQ Biotechnology Index is designed to track the performance of a set of securities listed on The NASDAQ Stock Market ® (NASDAQ ®) that are classified as either biotechnology or pharmaceutical according to the Industry Classification Benchmark (ICB). The NASDAQ Biotechnology Index is calculated under a modified capitalization-weighted methodology and ranked on an annual basis. All securities in the NASDAQ Biotechnology Index are listed on the NASDAQ Global Market or the NASDAQ Global Select Market, and meet minimum market value and share volume requirements among other criteria. The NASDAQ Biotechnology Index is the basis for the iShares NASDAQ Biotechnology Index SM Fund. In addition, options based on the iShares NASDAQ Biotechnology Index SM Fund trade on various exchanges. For more information about the NASDAQ Biotechnology Index, including eligibility criteria, visit www.nasdaq.com. About Spark Therapeutics Spark is a gene therapy leader seeking to transform the lives of patients with 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, recently 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. To learn more, please visit www.sparktx.com.