Nanosphere falls on not approvable letter for Plavix test

Nanosphere Inc. (NASDAQ:NSPH) fell $0.58 (26%) to $1.64 on Tuesday after FDA issued a not approvable letter for a PMA for its Verigene Clopidogrel Metabolism Nucleic Acid Test to guide therapy for cardiovascular drug Plavix clopidogrel. Nanosphere said it believes it can address the deficiencies cited by the agency, but would not disclose the specifics of the letter. ...