Spark Therapeutics, a late-stage company developing gene-based medicines for a wide range of rare, debilitating diseases, today announced the successful completion of a $72.8 million Series B financing led by Sofinnova Ventures. Joining Sofinnova as new investors in the company are Brookside Capital, Deerfield Management Company, Rock Springs Capital, funds and accounts managed by T. Rowe Price Associates, Inc., Wellington Management Company, LLP, and two undisclosed dedicated healthcare funds. The Children's Hospital of Philadelphia (CHOP), a co-founder of the company, also participated significantly in the round.

'With our combination of industry-leading gene therapy expertise, deep pipeline, and strong clinical results to-date, we've been able to attract a diverse set of blue-chip investors, giving us capital to maintain our position as a leader in the gene therapy field,' said Jeffrey D. Marrazzo, co-founder and CEO of Spark Therapeutics. 'The funding will support the expansion of our team and ongoing development of our pipeline as we build the infrastructure needed for a first-in-class, FDA-approved gene therapy.'

Funds will be used to advance the company's deep pipeline of gene therapy programs including development of its lead Phase 3 program to address RPE65-related retinal dystrophies, as well as support the company's growth over the next three years. Spark recently announced plans to open its corporate headquarters and manufacturing facility.

'The Spark team has significant experience across the core capabilities required to develop gene therapy products as evidenced by the quality of the company's pipeline and programs. The benefit provided by the RPE65 product candidate has the potential to be transformative for patients' lives. We are thrilled to lead this round of financing,' said Anand Mehra, M.D., General Partner of Sofinnova Ventures.

'Our goal from day one of CHOP's spin-out of Spark Therapeutics was to more effectively advance a deep clinical pipeline of gene therapy products with the potential to benefit patients. The strong support and interest from this group of highly respected investors provides incredible validation for both our clinical and business approach,' said Steven M. Altschuler, M.D., Chairman of the Board of Spark Therapeutics and CEO of The Children's Hospital of Philadelphia.

CHOP previously committed $50 million in funding as part of the launch of Spark Therapeutics in October 2013, investing $10 million in a Series A financing. CHOP's participation in this round brings its total equity investment in Spark to more than $30 million.

Spark's lead program addresses a specific form of inherited retinal dystrophy caused by mutations in the RPE65 gene. This program is currently in Phase 3 and builds on an earlier clinical study in which 12 patients with RPE65-related blindness demonstrated significant improvement, moving in some cases from being profoundly blind to being able to function in sighted classrooms, recognize faces, and walk independently. Spark also has a deep pipeline of programs behind the RPE65 program in other inherited retinal dystrophies, hematological disorders, and other rare diseases.

About Spark Therapeutics

Spark Therapeutics is developing curative, one-time gene therapy products with the potential to transform the lives of patients and re-imagine the treatment of debilitating diseases. Spark's lead gene therapy candidate, for RPE65-related blindness, is currently in Phase 3 clinical trials with the potential to be the first approved gene therapy in the United States, and the first treatment to address the significant unmet needs of patients living with blindness due to inherited retinal dystrophies. Additionally, the company has clinical and preclinical programs in other inherited retinal dystrophies and hematological disorders, and a proprietary manufacturing platform that has successfully supported human gene therapy trials across diverse therapeutic areas and routes of administration. Spark's founding team includes scientists who led the movement to develop gene therapy as a new treatment paradigm, establishing clinical proof of concept in the eye and liver and contributing key insights to the field that have resulted in a resurgence of industry interest in gene-based medicines. To learn more visit www.sparktx.com.