There's another mGluR5 antagonist in FXS but it is behind NVS' candidate http://clinicaltrials.gov/ct2/show/NCT00965432?term=NCT00965432&rank=1 Edit: This one started phase II last Nov. so it is also behind: http://clinicaltrials.gov/ct2/show/NCT01015430?term=NCT01015430&rank=1