Spark snags a 'breakthrough' tag for its Phase III gene therapy

Spark Therapeutics CEO Jeffrey Marrazzo

Gene therapy startup Spark Therapeutics has picked up the FDA's coveted breakthrough-therapy designation for its lead candidate, a one-time treatment that promises a permanent solution some rare eye diseases.

Spark's drug is designed to treat a group of vision-destroying ailments called inherited retinal dystrophies (IRDs), targeting the errant gene responsible for disease progression. The FDA's breakthrough designation applies to Spark's efforts in nyctalopia, or night blindness, in patients with a rare condition called Leber's congenital amaurosis. Spark's treatment, SPK-RPE65, is in the midst of a Phase III trial in IRDs, with data expected in the second half of next year.

By bestowing the breakthrough tag, the FDA is promising a speedy review for Spark's treatment once it's submitted in 2016, guaranteeing access to some of the agency's top minds in the process. The FDA based its decision on two earlier clinical trials in which one injection of SPK-RPE65 has helped nyctalopia gradually improve their vision, Spark said.

"FDA's breakthrough therapy designation for SPK-RPE65 underscores the serious unmet medical needs faced by patients with genetic blinding conditions," CEO Jeffrey Marrazzo said in a statement. "We look forward to working closely with FDA to facilitate the review of SPK-RPE65 as we work to bring this potentially transformative treatment to patients."

Spark, a 2014 Fierce 15 honoree, is also developing gene therapy candidates to treat hematologic and neurodegenerative disorders, advancing a pipeline whose promise helped the nascent biotech raise more than $80 million in under a year. The company spun out of the Children's Hospital of Philadelphia in 2013 with hopes of becoming a fully integrated pioneer in gene therapy, tapping the organization's expertise and recruiting a board of biopharma vets to light the way.

The company is part of a new class of biotechs responsible for a wave of newfound optimism for gene therapies. Serious safety issues and deliverability woes long hampered R&D in the field, but, after years of work, academics and investigators believe they have hammered out the right viral vectors to safely and predictably get corrective genes to their target tissues, spurring renewed hope for widespread clinical success.

And the industry's biggest players are taking notice. In September, Biogen Idec ($BIIB) made a splash in the field by unveiling plans to build an internal gene therapy division, one that will stand alongside its existing efforts in antisense therapies, biologics and traditional small molecules. Before that, Celgene ($CELG) teamed up with bluebird bio ($BLUE) on a gene therapy approach to oncology, and Bayer signed a $252 million deal with Fierce 15 winner Dimension Therapeutics to get its hands on a hemophilia A treatment. GlaxoSmithKline ($GSK), Baxter ($BAX) and others are working on in-house treatments in the field, as well.

- read the statement

Special Report: FierceBiotech's 2014 Fierce 15 - Spark Therapeutics

Editor's note: An earlier version of this story misstated how much money Spark has raised. We regret the error.