Stock market anomaly | Sanofi (SNY.US) falls nearly 9% before market opens, late-stage trial of atopic dermatitis drug shows efficacy below expectations.

According to the Securities Times APP, experimental drugs used by Sanofi (SNY.US) to treat skin disease atopic dermatitis have disappointed investors in late-stage trials, as the drug's efficacy is lower than expected. Following the announcement, as of the time of publication, the stock fell by as much as 9.3% in pre-market trading. As of Wednesday's close, the stock has already dropped by 18% in the past 12 months.