PHILADELPHIA, May 1, 2015 (GLOBE NEWSWIRE) -- Spark Therapeutics (Nasdaq:ONCE) today announced that it will have several presentations during the Annual Meeting of the Association for Research in Vision and Ophthalmology (ARVO), taking place in Denver, Colorado, from May 3 rd through May 7 th as well as at the Retina Gene Therapy conference in Denver on May 8 th. ARVO is the largest gathering of eye and vision researchers in the world, attracting over 11,000 attendees from more than 75 countries.

In its development of SPK-RPE65 as a potential gene therapy treatment for RPE65-mediated inherited retinal degenerations (IRDs), Spark is utilizing a proprietary mobility test of functional vision as the primary endpoint in its current Phase 3 clinical trial. While traditional vision tests, such as visual acuity or visual fields, measure discrete aspects of visual function, there is a growing need for a validated ability to measure functional vision in subjects with IRDs. The mobility test was designed to assess a subject's ability to function in a particular visual environment and to carry out typical activities of daily living, assessing light sensitivity, visual fields, visual acuity and navigational ability in one measure. Subjects in a Phase 1 clinical trial of SPK-RPE65 have been followed from two to four years after injection of the second eye and the levels of improvement from baseline generally have been maintained. These observations of durability are further supported by retinal sensitivity testing.

On Wednesday, May 6 th, Sarah McCague of The Children's Hospital of Philadelphia and Dr. Daniel Chung, Spark's Medical Affairs Ophthalmic Lead, will present a poster entitled "Mobility Testing Validation Study – Using a Novel, Standardized Mobility Test to Evaluate Functional Vision in Patients with Inherited Retinal Degeneration" detailing an evaluation of the construct and content validity, reliability and the ability of the mobility test to detect changes in functional vision over time. The study enrolled 60 subjects, including individuals with normal vision and with IRDs, and tracked changes in performance over a 12-month time period. The reliability and reproducibility of 12 different courses, as well as the change in performance in test subjects, will be presented.

On Friday May 8 th, Dr. Steve Russell, Professor of Ophthalmology at the University of Iowa and a Principal Investigator on Spark's Phase 3 clinical study of SPK-RPE65, will present at the Retina Gene Therapy conference organized by the Oregon Health and Science University Casey Eye Institute. Dr. Russell will present data on the use of Spark's mobility test in clinical studies of subjects with IRDs.

In addition to the presentations on the mobility test, on Tuesday, May 5 th, Dr. Chung and Karmen Trzupek of InformedDNA will present a poster entitled "Absence of Genotype-Phenotype Correlations in RPE65 Gene Mutations Associated with Autosomal Recessive Retinal Dystrophy". Subtypes of both Leber's congenital amourosis (LCA) and retinitis pigmentosa (RP) are caused by mutations in the RPE65 gene. This poster presents the results of the examination of various mutations in the RPE65 gene to determine whether genotype-phenotype correlations exist. A review of 125 discrete mutations showed no clear genotype-phenotype correlations between those diagnosed with LCA versus those diagnosed with RP. Thus, the distinction between RP, LCA and other clinical diagnoses of IRDs given to those with autosomal recessive mutations in RPE65 appears to be based primarily on clinical symptoms and age of onset rather than underlying genotype.

Further, Spark recently announced that it entered into an option agreement with Clearside Biomedical, Inc. under which Spark acquired exclusive rights to license Clearside's proprietary microinjector technology to deliver gene therapies to the back of the eye. At ARVO, Clearside will be presenting data on the ability of their microinjector to deliver drugs to the suprachoroidal space (SCS). Spark and Clearside will collaborate on testing the use of the microinjector for delivery of gene therapies to the choroid and the retina through the SCS.

About Spark Therapeutics

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 orphan 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, is in a fully enrolled pivotal Phase 3 clinical trial for the treatment of rare blinding conditions. Spark is leveraging the experience and technology utilized in the development of SPK-RPE65 to address a broad spectrum of blinding conditions, starting with the development of SPK-CHM for the potential treatment of choroideremia, currently in a Phase 1/2 clinical trial. Spark also is establishing a pipeline of gene therapy candidates to treat hematologic disorders and neurodegenerative diseases, including through a global collaboration with Pfizer Inc. around the development and commercialization of its SPK-FIX program for the treatment of hemophilia B. Spark's integrated gene therapy platform 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

Cautionary Note on Forward-looking Statements

This press release includes "forward-looking statements," within the meaning of the Private Securities Litigation Reform Act of 1995, that involve substantial risks and uncertainties. All statements, other than statements of historical facts, contained in this press release are forward-looking statements. The words "anticipate," "believe," "estimate," "expect," "intend," "may," "plan," "predict," "project," "target," "potential," "will," "would," "could," "should," "continue" and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. For example, the data from our Phase 3 clinical trial for SPK-RPE65 may be insufficient to support further development of the product candidate. For a discussion of other risks and uncertainties, and other important factors, any of which could cause our actual results to differ from those contained in the forward-looking statements, see the "Risk Factors" section of our most recent Annual Report on Form 10-K filed with the Securities and Exchange Commission.  We do not assume any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.
CONTACT: Investor Relations         Spark Therapeutics, Inc.         Stephen W. Webster         Chief Financial Officer         (888) 772-7560                  or                  Media Contact         FKH         Jessica Rowlands         (202) 729-4089

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