Study of SSP-004184 (SPD602) in Healthy Adults and Subjects With Impaired Liver Function

Inclusion Criteria:

- Age 18-65 years inclusive at the time of consent.

- Willingness to comply with any applicable contraceptive requirements of the protocol
and is:

- Male, or

- Non pregnant, non lactating female

- Females must be at least 90 days post partum or nulliparous.

Subjects who do not have hepatic impairment (healthy subjects)

- Normal renal function.

Subjects with hepatic impairment

- Subjects must provide a letter of evaluation from a hepatologist or copy of
supporting documents confirming the subject's hepatic impairment (a liver biopsy is
preferable but not mandatory).

- Hepatic impairment should be primary and must not be a complication of an underlying
primary systemic disease (eg, patients with metastatic cancer and cancer cachexia)

- Documented chronic stable liver impairment

Exclusion Criteria

Subjects who do not have hepatic impairment (healthy subjects)

- A positive HIV antibody screen, Hepatitis B surface antigen, or Hepatitis C virus
antibody screen.

Subjects with hepatic impairment

- Presence of a hepatocellular carcinoma, or an acute hepatic disease caused by an
infection or drug toxicity.

- Presence of surgically created or transjugular intrahepatic portal systemic shunts.

- A positive HIV antibody screen.

- Renal insufficiency.

All subjects

- Subject has a history of thyroid disorder.

- History of nephrotic syndrome.

- History of alcohol or other substance abuse within the last year.

- A positive screen for alcohol or drugs of abuse.

- Male subjects who consume more than 3 units of alcohol per day. Female subjects who
consume more than 2 units of alcohol per day. (1 alcohol unit = 1 beer [12 oz/355
mL] = 1 wine [5 oz/150 mL] = 1 liquor [1.5 oz/40 mL] = 0.75 oz/20 mL alcohol.)

- Caffeine consumption: For healthy subjects: Routine consumption of more than 2 units
of caffeine per day or subjects who experience caffeine withdrawal headaches or have
a history of caffeine withdrawal headaches. (One caffeine unit is contained in the
following items: one 6 oz/180 mL cup of coffee, two 12 oz/355 mL (ie, 24 oz/710 mL
cola) cans of cola, one 12 oz/355 mL cup of tea, three 1 oz/28 g chocolate bars (ie,
3 oz/85 g chocolate). Decaffeinated coffee, tea, or cola are not considered to
contain caffeine.)

- Donation of blood or blood products within 60 days.

- Substantial changes in eating habits within 30 days.