Crossover Study to Evaluate the Efficacy of AR11 in Pediatric Patients With ADHD in a Laboratory Classroom Setting

Inclusion Criteria:

1. Male or female between 6 and 12 years of age, inclusive, at the time of Screening.

2. Diagnosed as meeting Diagnostic and Statistical Manual of Mental Disorders, Fourth
Edition, Text Revision (DSM-IV-TR) criteria for ADHD.

3. A clinician-administered Clinical Global Impression of Severity (CGI-S) score of 3 or
greater.

4. An ADHD Rating Scale (ADHD-RS) score at Screening and Baseline greater than or equal
to the 90th percentile normative values for gender and age in at least one of the
following categories: hyperactive-impulsive subscale, inattentive subscale, or total
score.

Exclusion Criteria:

1. Secondary or co-morbid diagnoses other than ADHD, with the exception of simple
phobias, oppositional defiant disorder, elimination disorders, motor skills
disorders, communication disorders, learning disorders, adjustment disorders, and
sleep disorders if, in the opinion of the investigator, the associated symptoms do
not confound assessment of safety or efficacy.

2. Clinically significant cognitive impairment as assessed in the clinical judgment of
the Investigator.

3. History of any of the following medical disorders: seizure disorder (excluding a
history of febrile seizures), structural cardiac disorders, serious cardiac
conditions, hypertension, untreated thyroid disease, glaucoma, Tourette's disorder,
or chronic tics.

4. Clinically significant abnormal ECG finding or abnormal cardiac finding on physical
exam (including presence of a pathologic murmur) at Screening.

5. Use of any psychotropic medication (sedative hypnotics prescribed as a sleep aid at a
stable dose for at least 30 days prior to Baseline, at bedtime only, are allowed
during the study).

6. A history of hypersensitivity or intolerance to any formulation of amphetamine or
lisdexamfetamine.