Nuedexta for the Treatment of Adults With Autism

This is a randomized placebo-controlled crossover study. The parents, neuropsychologists,
clinical research coordinator (CRC) and PI will be blinded as to whether subjects are on
placebo or Nuedexta.

Nuedexta will be given once daily for 7 days. If well-tolerated, it will be given every 12
hours for the next 7 weeks. Patients may also remain on the once-daily dose if desired.

The study will last 44 weeks. This includes 20 weeks for study enrollment, 8 weeks of
treatment/placebo, 4 weeks for washout, and a second 8 week-period of treatment/placebo
followed by 4 weeks of washout.

Subjects will be randomized to 8 weeks of Nuedexta/placebo. After the 8 week follow-up visit,
there will be a 4 week washout period. At week 12 (second baseline), the groups will
crossover for another 8 weeks of Nuedexta/placebo. Study endpoints will be measured in the
both groups at weeks 8, 12, and 20. A final study visit will occur at week 24.

Inclusion Criteria:

1. 18 to 60 years of age

2. Have a collateral informant who can attend visit and answer questionnaires pertaining
to participant behavior

3. Diagnosis of autistic spectrum disorder based on the Diagnostic and Statistical
Manual, 4th edition, Text Revised (DSM-IV-TR) criteria, developmental history, and
Autism Diagnostic Observation Schedule (ADOS); or confirmed diagnosis of autism during
childhood through similar methods

4. Capable of giving informed consent, or have a legal guardian capable of giving consent
on the subject's behalf; patient able to assent to participate

5. Mood issues and frontal lobe type perseveration issues

6. No medication changes within 30 days and no use of new medications during the course
of the study except for non-related conditions approved by the investigators

Exclusion Criteria:

1. Clinically uncontrolled epilepsy

2. Cardiovascular conditions including cardiac or structural malformation heart failure,
prolonged QT interval, history of torsades de pointes, or atrioventricular (AV) block

3. Known genetic disorders, fragile x, or known brain structural abnormalities, cerebral
palsy, head injury, or brain tumor

4. Known allergy to either dextromethorphan or quinidine

5. Concurrent or recent use of Monoamine oxidase inhibitor (MAOI) antidepressants pt
Nuedexta

6. Concurrent use of lamotrigine or felbamate or other N-Methyl-D-aspartate (NMDA)
agonists or antagonists

7. Thrombocytopenia, hepatitis, bone marrow depression or lupus-like syndrome

8. Pregnancy - sexually active females of childbearing potential must be on a reliable
form of contraception

9. Other clinically significant abnormality on physical, neurological, laboratory, vital
signs, that could compromise the study or be detrimental to the subject