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Spark Therapeutics initiates enrolment of Phase I/II study for choroideremia gene therapy treatment

Spark Therapeutics, Inc. (NASDAQ: ONCE) has initiated enrolment of a Phase I/II gene therapy study in choroideremia (CHM), an X-linked retinopathy, manifesting as night-blindness in affected males, and characterised by an increasing constriction of the visual field, ultimately leading to complete blindness. The pathology is understood to arise from mutations in the CHM gene leading to a defective or absent Rab escort protein-1 (REP-1). The company estimates that CHM affects approximately 12,500 males in the US and five of the major European markets. The study, an open-label dose escalating safety and preliminary efficacy trial, aims to enrol up to 10 subjects and to begin dosing in the first quarter of FY2015.


According to the company, preclinical studies conducted in collaboration with Jean Bennett, M.D., Ph.D., F.M. Kirby Professor of Ophthalmology at the Perelman School of Medicine, University of Pennsylvania (Penn), have previously demonstrated the ability to restore REP-1 protein production, intracellular trafficking and retinal structure in models of CHM. The same clinical study teams that have progressed the company’s lead therapeutic, SPK-RPE65, to Phase III, will now be leveraged to conduct the SPK-CHM Phase I/II study. Commenting on the clinical milestone, Jefferey D. Marazzo, co-founder and Chief executive Officer of Spark stated that, “Choroideremia is a rare, blinding condition which affects males most severely at middle age, a critical time personally and professionally. It is our hope that with SPK-CHM we can build on our experience with our lead program, SPK-RPE65, potentially bringing a treatment to these patients in need.” Also commenting on the achievement Prof. Jean Bennett stated, “Throughout my career’s work developing genetic therapies for inherited retinal dystrophies, I have had my target set on a number of different conditions, in particular, choroideremia. The SPK-CHM program, for the first time, creates the potential for patients to use their vision for longer and see more things.”


Spark Therapeutics, Inc., made an impressive IPO debut on the NASDAQ, Friday, January 30th gaining a substantial 117% jump in price, from an original offer of $23 per share to close out their first day of trading at $50.65. The company raised $161M from selling all offer stock at the $23/share price valuing the company at approximately $1.5 billion by the end of the day. The company’s lead therapy in Phase 3 clinical trials is for the treatment of RPE65-mediated inherited retinal degeneration.   The company anticipates reporting final results from their SPK-RPE65 clinical study in the second half of 2015.   If successful, their first product could be ready for submission of a biological license application (BLA) at the FDA in early 2016 with a potential product launch between Q2 and Q4 of the same year.