The main objectives of the study were to assess the effects of Obeticholic Acid (OCA) on serum alkaline phosphatase (ALP) and total bilirubin, together as a composite endpoint and on safety in participants with primary biliary cirrhosis (PBC).

The study included 2 phases: a 12-month randomized, double-blind (DB), placebo-controlled, parallel group phase, followed by a long-term safety extension (LTSE) phase up to 5 years. Participants from the 12-month DB phase, including those who received placebo, were eligible to participate in the open-label LTSE phase. The Month 12 visit from the DB phase served as the Day 1 visit of the LTSE phase. After completion of the 12-month DB phase all participants were offered the opportunity to enter an open-label LTSE for up to 5 years beginning at 5 mg OCA.

Data for the LTSE phase is reported by the randomized dose group assigned in the DB phase.

Inclusion Criteria:

1. Definite or probable PBC diagnosis (consistent with American Association for the Study of Liver Disease [AASLD] and European Association for Study of the Liver [EASL] Practice Guidelines; [Lindor 2009; EASL 2009]), as demonstrated by the presence of ≥ 2 of the following 3 diagnostic factors:

   • History of elevated alkaline phosphatase (ALP) levels for at least 6 months
   • Positive antimitochondrial antibodies (AMA) titer or if AMA negative or in low titer (<1:80) PBC specific antibodies (anti-GP210 and/or anti-SP100 and/or antibodies against the major M2 components (pyruvate dehydrogenase complex-E2 [PDC-E2], 2-oxo-glutaric acid dehydrogenase complex)
   • Liver biopsy consistent with PBC

2. At least 1 of the following qualifying biochemistry values:

   • ALP ≥ 1.67x upper limit of normal (ULN)
   • Total bilirubin > ULN but < 2x ULN

3. Age ≥ 18 years

4. Taking ursodeoxycholic acid (UDCA) for at least 12 months (stable dose for ≥ 3 months) prior to Day 0, or unable to tolerate UDCA (no UDCA for ≥ 3 months) prior to Day 0.

5. Contraception: Female participants must be postmenopausal, surgically sterile, or if premenopausal, be prepared to use ≥ 1 effective (≤ 1% failure rate) method of contraception during the trial and for 30 days after the end of treatment (EOT) visit. Effective methods of contraception are considered to be:

   • Hormonal (for example, contraceptive pill, patch, intramuscular implant or injection); or
   • Double barrier method, that is, (a) condom (male or female) or (b) diaphragm, with spermicide; or
   • Intrauterine device (IUD); or
   • Vasectomy (partner); or
   • Sexual abstinence

6. Must provide written informed consent and agree to comply with the trial protocol.

Exclusion Criteria:

1. History or presence of other concomitant liver diseases including:

   • Hepatitis C virus (HCV) infection; participants with active hepatitis B (HBV) infection will be excluded, however, participants who have seroconverted (hepatitis B surface antigen [Hbs Ag] and hepatitis B e antigen [Hbe Ag] negative) may be included after consultation with the medical monitor.
   • Primary sclerosing cholangitis (PSC)
   • Alcoholic liver disease
   • Definite autoimmune liver disease or overlap hepatitis
   • Nonalcoholic steatohepatitis (NASH)
   • Gilbert's Syndrome (due to interpretability of bilirubin levels)

2. Presence of clinical complications of PBC or clinically significant hepatic decompensation, including:

   • History of liver transplantation, current placement on a liver transplant list or current Model for End Stage Liver Disease (MELD) score ≥ 15
   • Portal hypertension with complications, including: known gastric or large esophageal varices, poorly controlled or diuretic resistant ascites, history of variceal bleeds or related therapeutic or prophylactic interventions (for example, beta blockers, insertion of variceal bands or transjugular intrahepatic portosystemic shunt [TIPS]), or hepatic encephalopathy
   • Cirrhosis with complications, including history or presence of: spontaneous bacterial peritonitis, hepatocellular carcinoma, bilirubin > 2x ULN
   • Hepatorenal syndrome (type I or II) or Screening serum creatinine > 2 mg/deciliter dL) (178 micromole [µmol])/liter [L])

3. Participants with severe pruritus or those requiring systemic treatment for pruritus (for example, with bile acid sequestrants [BAS] or rifampicin) within 2 months of Day 0 will be excluded

4. Administration of the following medications is prohibited as specified below:

   • Prohibited 6 months prior to Day 0 and throughout the trial (that is, to last dose and/or EOT): azathioprine, colchicine, cyclosporine, methotrexate, mycophenolate mofetil, pentoxifylline; fenofibrate or other fibrates; budesonide and other systemic corticosteroids; potentially hepatotoxic drugs (including α-methyl-dopa, sodium valproic acid, isoniazide, or nitrofurantoin)
   • Prohibited 12 months prior to Day 0 and throughout the trial (that is, to last dose and/or EOT): antibodies or immunotherapy directed against interleukins or other cytokines or chemokines

5. Participants who have previously participated in a clinical trial of OCA will not be allowed to participate

6. History or presence of clinically concerning cardiac arrhythmias likely to affect survival during the trial, or prolongation of Screening (pretreatment) QT or QTc interval of > 500 milliseconds (msec)

7. If female: known pregnancy, or has a positive urine pregnancy test (confirmed by a positive serum pregnancy test), or lactating

8. Known history of human immunodeficiency virus (HIV) infection

9. Presence of any other disease or condition that is interfering with the absorption, distribution, metabolism, or excretion of drugs including bile salt metabolism in the intestine. Participants with inflammatory bowel disease or who have undergone gastric bypass procedures will be excluded (gastric lap band is acceptable).

10. Medical conditions that may cause nonhepatic increases in ALP (for example, Paget's disease) or which may diminish life expectancy to < 2 years, including known cancers (except carcinomas in situ or other stable, relatively benign conditions such as chronic lymphatic leukemia)

11. Other clinically significant medical conditions that are not well controlled or for which medication needs are anticipated to change during the trial

12. Anticipated changes to current concomitant medications during the course of the trial

13. History of alcohol abuse, defined as consumption of more than 210 mL of alcohol per week (that is, the equivalent of fourteen 4-ounce (125 mL) glasses of wine or fourteen 12 ounce cans/bottles of beer), or other substance abuse within 1 year prior to Day 0

14. Participation in another investigational drug, biologic, or medical device trial within 30 days prior to Screening

15. History of noncompliance with medical regimens, or participants who are considered to be potentially unreliable

16. Blood or plasma donation within 30 days prior to Day 0

17. Mental instability or incompetence, such that the validity of informed consent or compliance with the trial is uncertain