Spark Therapeutics’ promising gene therapy for vision loss could cost $1 million By: MarketWatch October 13, 2017 at 15:44 PM EDT The development could be a major, if costly, milestone for both the disease and the field of gene therapy. Read More >> Related Stocks: Adverum Biotechnologies Inc Biomarin Pharmaceuticals Bluebird Bio Boundless Bio Inc Novartis Ag ADR Spark Therap Voyager Therapeut