A Study Examining Doses of Abiraterone Acetate in Adult Women With 21-Hydroxylase Deficiency

This is a non-randomized (patients will not be assigned by chance to study treatments),
open-label (patients will know the identity of study treatments), multiple-dose,
intra-patient sequential dose-escalation study with a planned enrollment of approximately 10
patients. This study will consist of a screening period and a treatment period. Due to the
intra-patient dose escalation, there will be multiple treatment periods consisting of 8 days
each. A rest period of at least 7 days will separate each treatment period. Eligible
patients will take study-defined replacement doses of hydrocortisone and fludrocortisone.
Abiraterone acetate oral suspension will be administered in daily escalating doses from 100
mg to 500 mg. Patients will proceed to the next higher dose level when the majority of the
treated patients have a reduction in the androstenedione level. Serial pharmacokinetic
(study of what the body does to a drug) and pharmacodynamic (study of the effects of a drug
on the body) samples will be collected at each treatment period as detailed in the protocol.
All patients who receive at least 1 dose of abiraterone acetate will be analyzed for safety.

Inclusion Criteria:

- Premenopausal women >=18 years of age.

- Must be receiving a hormonal contraceptive agent containing both estrogen and
progesterone.

- Confirmed 21-hydroxylase deficiency by CYP21A2 genotype associated with classic
congenital adrenal hyperplasia.

- Demonstrates a >=1.5 X ULN of morning serum androstenedione concentration while
taking study-defined doses of hydrocortisone and fludrocortisone.

- No coexisting medical conditions in the opinion of the investigator that would
preclude participation in the study.

Exclusion Criteria:

- Current or history of active or chronic hepatitis, including symptomatic viral
hepatitis A, B, or C.

- Any active infection.

- Evidence of active malignancy.

- Serious or uncontrolled co-existent non-malignant disease.

- Receiving systemic glucocorticoids for any reason other than for the treatment of
21-hydroxylase deficiency.

- Any disorders that require treatment with anticonvulsants.

- Patients of child-bearing potential who are not willing to use a method of birth
control during the study and for 3 months after the end-of-study.

- Women who are pregnant or breast-feeding.

- Genotypes associated with non-classic congenital adrenal hyperplasia.