Obeticholic acid

Obeticholic acid may increase the exposure to concomitant medicinal products that are CYP1A2 substrates. Therapeutic monitoring of CYP1A2 substrates with narrow therapeutic index (e.g. theophylline and tizanidine) is recommended.

Bile acid binding resins such as cholestyramine, colestipol, or colesevelam adsorb and reduce bile acid absorption and may reduce efficacy of obeticholic acid. When concomitant bile acid binding resins are administered, obeticholic acid should be taken at least 4-6 hours before or 4-6 hours after taking a bile acid binding resin, or at as great an interval as possible.

International normalised ratio (INR) is decreased following co-administration of warfarin and obeticholic acid. INR should be monitored and the dose of warfarin adjusted, if needed, to maintain the target INR range when co-administering obeticholic acid and warfarin.

Patients at increased risk of hepatic decompensation, including those with elevated bilirubin levels, evidence of portal hypertension (e.g., ascites, gastroesophageal varices, persistent thrombocytopenia), concomitant hepatic disease (e.g., autoimmune hepatitis, alcoholic liver disease), and/or severe intercurrent illness should be closely monitored to determine whether obeticholic acid treatment discontinuation is needed.

There are no data on the use of obeticholic acid in pregnant women. Animal studies do not indicate direct or indirect harmful effects with respect to reproductive toxicity. As a precautionary measure, it is preferable to avoid the use of obeticholic acid during pregnancy.

It is unknown whether obeticholic acid is excreted in human milk. Based on animal studies and intended pharmacology, obeticholic acid is not expected to interfere with breast-feeding or the growth or development of a breast-fed child. A decision must be made whether to discontinue breast-feeding or to discontinue/abstain from obeticholic acid therapy taking into account the benefit of breast-feeding for the child and the benefit of therapy for the woman.

Fertility

No fertility data is available in humans. Animal studies do not indicate any direct or indirect effects on fertility or reproduction.

Obeticholic acid has no or negligible influence on the ability to drive and use machines.

Summary of the safety profile

The most commonly reported adverse reactions were pruritus (63%) and fatigue (22%). The most common adverse reaction leading to discontinuation was pruritus. The majority of pruritus occurred within the first month of treatment and tended to resolve over time with continued dosing.

Tabulated list of adverse reactions

The adverse reactions reported with obeticholic acid are listed in the table below by MedDRA system organ class and by frequency. Frequencies are defined as: very common (≥1/10), common (≥1/100 to <1/10), uncommon (≥1/1,000 to <1/100), rare (≥1/10,000 to <1/1,000), very rare (<1/10,000) and not known (cannot be estimated from the available data).

Frequency of adverse reactions in PBC patients:

Description of selected adverse reactions

Discontinuation of treatment

Adverse reactions leading to discontinuation of treatment were 1% (pruritus) in the obeticholic acid titration arm and 11% (pruritus and fatigue) in the obeticholic acid 10 mg arm.

Pruritus

Approximately 60% of patients had a history of pruritus upon enrollment in the phase III study. Treatment-emergent pruritus generally started within the first month following the initiation of treatment.

Relative to patients who started on 10 mg once daily in the obeticholic acid 10 mg arm, patients in the obeticholic acid titration arm had a lower incidence of pruritus (70% and 56%, respectively) and a lower discontinuation rate due to pruritus (10% and 1%, respectively).

The percentages of patients who required interventions (i.e., dose adjustments, treatment interruptions, or initiation of antihistamines or bile acid binding resins) were 41% in the obeticholic acid 10 mg arm, 34% in the obeticholic acid titration group, and 19% in the placebo group.