An Open-Label Safety Study of Memantine in Pediatric Patients With Autism, Asperger's Disorder, or Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS)

This 50-week multicenter clinical study is comprised of a 2-week screening period, a 6-week
open-label dose-titration period followed by up to 42-week open-label maintenance period.

Approximately 192 pediatric patients (aged 6-12 years) may enter this study at approximately
180 study centers. Patients with at least 12 weeks of investigational product exposure who
meet the protocol specified responder criterion will be eligible to transition to a
randomized withdrawal study.

Inclusion Criteria:

1. Male or female outpatients.

2. Age of 6-12.

3. Meet Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text
Revision (DSM-IV-TR) diagnostic criteria for autism, Asperger's Disorder, or
Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS)

4. Have a family that is sufficiently organized and stable to guarantee adequate safety
monitoring and continuous attendance to clinic visits for the duration of the study

Exclusion Criteria:

1. Have enrolled in Study MEM-MD-57A

2. Medical conditions that might interfere with the conduct of the study, confound
interpretation of the study results, or endanger the patient's well-being.

3. Participation in any other clinical investigation using an experimental drug within
30 days of screening.

4. Having any primary psychiatric (Axis I) diagnosis other than autism, Asperger's
Disorder, and PDD-NOS.

5. Meeting DSM-IV-TR criteria for bipolar I disorder, psychotic disorder not otherwise
specified, posttraumatic stress disorder, schizophrenia, or major depressive disorder
within the past 6 months