Teva Pharmaceutical Industries Ltd. announced that it has received a Complete Response Letter (CRL) from the U.S. Food and Drug Administration (FDA) regarding the New Drug Application (NDA) for SD-809 (deutetrabenazine) tablets for the treatment of chorea associated Huntington disease (HD). This is the first deuterated product to be reviewed by the FDA. The FDA has asked Teva to examine blood levels of certain metabolites. These metabolites are not novel, and are the same seen in subjects who take tetrabenazine or deutetrabenazine. No new clinical trials have been requested.