Sarepta Therapeutics falls after FDA probes death of Elevidys patient

** Shares of drugmaker Sarepta Therapeutics SRPT.O fall 7% to $11.10 in extended trading

** The US FDA says it is investigating the death of an 8-year-old boy who received Elevidys, a gene therapy for Duchenne muscular dystrophy

** Roche ROG.S, which partners with Sarepta outside the U.S., said the boy was treated with Elevidys and was not a participant in a clinical trial

** "The reporting physician has assessed the death as unrelated to treatment with Elevidys," says Roche

** This is the third reported death of a patient who received Elevidys, and the fourth death this year tied to Sarepta's gene therapies

** The boy died on June 7 - FDA

** Last week, the agency asked Sarepta to voluntarily halt shipments of Elevidys

** Stock down 90% YTD