Spark falls on UPenn's transient results in LCA

Spark Therapeutics Inc. (NASDAQ:ONCE) slipped $3.51 to $55.01 on Monday after two studies in the New England Journal of Medicine showed that treatment effects of gene therapies declined over time in patients with Leber congenital amaurosis (LCA). Researchers had hoped the effects would be permanent.

Neither study included any of Spark's therapies. The company is conducting a Phase III trial of SPK-RPE65 ( AAV2-hRPE65v2) to treat LCA caused by mutations in the RPE65 gene. ...