Fragile X Investigational Drug Study (Adult)

The purpose of this study is to find out whether an experimental drug is safe and effective for treating fragile X syndrome symptoms, when taken for as long as 24 months or until the drug becomes available on the market (whichever occurs later). In this study all study subjects will be treated with the active investigational drug for the entire study and there will be no placebo.

This product is an investigational drug that is not approved for use for the treatment of people with fragile X syndrome by the U.S. Food and Drug Administration.

This product is a drug that blocks the so-called mGluR5 receptor in the brain. A receptor can be thought of as a "lock" and this drug as a "key" which fits into the lock to stop it from being active. This drug can block the mGluR5 receptor that has increased activity in fragile X patients. By blocking this receptor, it is thought that the symptoms of fragile X syndrome may be reduced.

In order to participate you must meet the following criteria:

• Are an individual who participated in the earlier 2212 placebo-controlled study.

This is a partial list of eligibility requirements.