Mizuho analyst Difei Yang lowered her price target for Spark Therapeutics (ONCE) to $77 after the company provided an update on the SPK-8011 program for hemophilia A. While the latest data appears "somewhat mixed" with two out of the seven patients not maintaining Factor VIII level of at least 12%, Spark offered a reasonable explanation and proposal to address the issue in the upcoming Phase III trial that is scheduled to begin in Q4, Yang tells investors in a research note. The analyst finds it premature to draw the conclusion that SPK-8011 is inferior to the competing product from BioMarin (BMRN). Yang removed a takeover premium for Spark in her new price target but keeps a Buy rating on the shares.