5.1       Pancreatitis

Pancreatitis, with or without sphincter of Oddi spasm [see Warnings and Precautions (5.1)], has been reported in patients taking either the 75 mg or 100 mg dosage of VIBERZI, including serious cases resulting in hospitalization, primarily in patients without a gallbladder. Fatal cases have also been reported in patients without a gallbladder. VIBERZI is contraindicated in patients without a gallbladder [see Contraindications (4)].  Most of the reported cases of serious pancreatitis occurred within a week of starting treatment with VIBERZI and some developed symptoms after one to two doses.   

In patients with a gallbladder, evaluate a patient’s alcohol intake prior to starting VIBERZI. Instruct patients to avoid chronic or acute excessive alcohol use while taking VIBERZI. Monitor for new or worsening abdominal pain that may radiate to the back or shoulder, with or without nausea and vomiting. Instruct patients to immediately stop VIBERZI and seek medical attention if they experience symptoms suggestive of pancreatitis such as acute abdominal or epigastric pain radiating to the back or shoulder associated with elevations of pancreatic enzymes with or without nausea and vomiting [see Contraindications (4)].

5.2       Sphincter of Oddi Spasm

There is a risk of sphincter of Oddi spasm, resulting in pancreatitis or hepatic enzyme elevation associated with acute abdominal pain (e.g., biliary-type pain) in patients taking VIBERZI [see Adverse Reactions (6.1)]. Postmarketing serious adverse reactions of sphincter of Oddi spasm with or without pancreatitis resulting in hospitalization have been reported, primarily in patients without a gallbladder [see Warnings and Precautions (5.1)]. Most of the reported cases of serious sphincter of Oddi spasm occurred within a week of starting treatment with VIBERZI and some developed symptoms after one to two doses. VIBERZI is contraindicated in patients without a gallbladder [see Contraindications (4)].

Instruct patients to immediately stop VIBERZI and seek medical attention if they experience symptoms suggestive of sphincter of Oddi spasm such as acute worsening of abdominal pain, (e.g. acute epigastric or biliary [i.e., right upper quadrant] pain), that may radiate to the back or shoulder with or without nausea and vomiting, associated with elevations of pancreatic enzymes or liver transaminases. Do not restart VIBERZI in patients who developed biliary duct obstruction or sphincter of Oddi spasm while taking VIBERZI [see Contraindications (4)].

5.3       Hypersensitivity Reactions

In postmarketing experience, serious hypersensitivity reactions (including anaphylaxis) have been reported following VIBERZI administration. Some of these reactions occurred after the first one or two doses of VIBERZI [see Adverse Reactions (6.2)].

Instruct patients to immediately stop VIBERZI and seek medical attention if they experience symptoms suggestive of a hypersensitivity reaction [see Contraindications (4)].

5.4       Constipation

Constipation, sometimes requiring hospitalization, has been reported following VIBERZI administration. In postmarketing experience, severe cases with development of intestinal obstruction, intestinal perforation, and fecal impaction, requiring intervention, have also been reported. Instruct patients to stop VIBERZI and immediately contact their healthcare provider if they experience severe constipation. Avoid use with other drugs that may cause constipation [see Adverse Reactions (6.1), Drug Interactions (7)].

6.1       Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Over 1700 patients with IBS-D have been treated with 75 or 100 mg of VIBERZI twice daily in controlled trials. Exposures from placebo-controlled clinical trials in adult patients with IBS-D included 1391 exposed for 3 months, 1001 exposed for 6 months and 488 exposed for one year. 

Demographic characteristics were comparable between the treatment groups [see Clinical Studies (14)]. Data described below represent pooled data compared to placebo across the randomized trials.

Pancreatitis

Cases of pancreatitis, not associated with sphincter of Oddi spasm, were reported in 2/807 (0.2%) of patients receiving 75 mg and 3/1032 (0.3%) of patients receiving 100 mg VIBERZI twice daily in clinical trials. Of these 5 cases, 3 were associated with excessive alcohol intake, one was associated with biliary sludge, and in one case the patient discontinued VIBERZI 2 weeks prior to the onset of symptoms. All pancreatic events resolved with lipase normalization upon discontinuation of VIBERZI, with 80% (4/5) resolving within 1 week of treatment discontinuation. The case of sphincter of Oddi spasm-induced pancreatitis resolved within 24 hours of discontinuation.

Sphincter of Oddi Spasm

In clinical trials, sphincter of Oddi spasm occurred in 0.2% (2/807) of patients receiving 75 mg and 0.8% (8/1032) of patients receiving 100 mg VIBERZI twice daily.

• Among patients receiving 75 mg, 1/807 (0.1%) patient experienced a sphincter of Oddi spasm presenting with abdominal pain but with lipase elevation less than 3 times the upper limit of normal (ULN) and 1/ 807 (0.1%) patient experienced a sphincter of Oddi spasm manifested as elevated hepatic enzymes associated with abdominal pain
  
• Among patients receiving 100 mg, 1/1032 (0.1%) patient experienced a sphincter of Oddi spasm manifested as pancreatitis and 7/1032 (0.7%) patients experienced sphincter of Oddi spasm manifested as elevated hepatic enzymes associated with abdominal pain

Of those patients who experienced a sphincter of Oddi spasm, 80% (8/10) reported their first onset of symptoms within the first week of treatment. The case of sphincter of Oddi spasm-induced pancreatitis occurred within minutes of taking the first dose of VIBERZI. No cases of sphincter of Oddi spasm occurred greater than 1 month after treatment onset. All events resolved upon discontinuation of VIBERZI, with symptoms typically improved by the following day.

Common Adverse Reactions

Table 1 provides the incidence of common adverse reactions reported in > 2% of IBS-D patients in either VIBERZI treatment group and at an incidence greater than in the placebo group.

* Reported in > 2% of VIBERZI-treated patients at either dose and at an incidence greater than in placebo-treated patients

**"Abdominal Pain" term includes: abdominal pain, abdominal pain lower, and abdominal pain upper

*** "Rash" term includes: dermatitis, dermatitis allergic, rash, rash erythematous, rash generalized, rash maculo-papular, rash papular, rash pruritic, urticaria, and idiopathic urticaria

Constipation was the most commonly reported adverse reaction in VIBERZI-treated patients in these trials. Approximately 50% of constipation events occurred within the first 2 weeks of treatment while the majority occurred within the first 3 months of therapy. Rates of severe constipation were less than 1% in patients receiving 75 mg and 100 mg VIBERZI. Similar rates of constipation occurred between the active and placebo arms beyond 3 months of treatment.

Adverse Reactions Leading to Discontinuation

Eight percent of patients treated with 75 mg, 8% of patients treated with 100 mg VIBERZI and 4% of patients treated with placebo discontinued prematurely due to adverse reactions. In the VIBERZI treatment groups, the most common reasons for discontinuation due to adverse reactions were constipation (1% for 75 mg and 2% for 100 mg) and abdominal pain (1% for both 75 mg and 100 mg). In comparison, less than 1% of patients in the placebo group withdrew due to constipation or abdominal pain.

Less Common Adverse Reactions

Adverse reactions that were reported in ≤ 2% of VIBERZI-treated patients are listed below by body system.

Gastrointestinal: gastroesophageal reflux disease
General Disorders and administration site conditions: feeling drunk
Investigations: increased AST
Nervous system: sedation, somnolence
Psychiatric disorders: euphoric mood
Respiratory: asthma, bronchospasm, respiratory failure, wheezing

6.2       Postmarketing Experience

The following adverse reactions have been identified during post-approval use of VIBERZI. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Hypersensitivity: anaphylaxis, angioedema (e.g. swollen face and throat), dyspnea, throat tightness, and chest pain/tightness [see Warnings and Precautions (5.3)].

8.1       Pregnancy

Risk Summary

There are no studies with VIBERZI in pregnant women that inform any drug-associated risks. The background risk of major birth defects and miscarriage for the indicated population is unknown. However, the background risk in the U.S. general population of major birth defects is 2 to 4% and of miscarriage is 15 to 20% of clinically recognized pregnancies. In animal reproduction studies, oral and subcutaneous administration of eluxadoline to rats and rabbits during organogenesis at doses approximately 51 and 115 times the human exposure after a single oral dose of 100 mg, respectively, demonstrated no teratogenic effects. In a pre- and postnatal development study in rats, no adverse effects were observed in offspring with oral administration of eluxadoline at doses approximately 10 times the human exposure (see Data).

Data

Animal Data

Eluxadoline administered as combined oral (1000 mg/kg/day) and subcutaneous (5 mg/kg/day) doses during the period of organogenesis to rats and rabbits (exposures about 51 and 115 times, respectively, the human AUC of 24 ng.h/mL after a single oral dose of 100 mg) did not cause any adverse effects on embryofetal development. A pre- and postnatal development study in rats showed no evidence of any adverse effect on pre- and postnatal development at oral doses of eluxadoline up to 1000 mg/kg/day (with exposures about 10 times the human AUC of 24 ng.h/mL after a single oral dose of 100 mg). In the same study, eluxadoline was detected in the milk of lactating rats administered oral doses of 100, 300 and 1000 mg/kg/day (with exposures about 1.8, 3 and 10 times, respectively, the human AUC of 24 ng.h/mL after a single oral dose of 100 mg). Milk samples were collected from six lactating females per group on lactation day 12. Mean concentrations of eluxadoline in the milk of lactating rats on lactation day 12 were 2.78, 5.49 and 44.02 ng/mL at 100, 300 and 1000 mg/kg/day, respectively.

8.2       Lactation

Risk Summary

No data are available regarding the presence of eluxadoline in human milk, the effects of eluxadoline on the breastfed infant, or the effects of eluxadoline on milk production.  However, eluxadoline is present in rat milk [see Use in Specific Populations (8.1)].

The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for VIBERZI and any potential adverse effects on the breastfed infant from VIBERZI or from the underlying maternal condition.

8.4       Pediatric Use

Safety and effectiveness in pediatric patients have not been established.

Juvenile Toxicology Data

Eluxadoline was orally administered to juvenile rats at 500, 750, and 1500 mg/kg/day (about 16, 54 and 30 times, respectively, the human AUC of 24 ng.h/mL after a single oral dose of 100 mg) for 4 weeks. There were no adverse physiologic effects related to eluxadoline. Based on these results, the NOAEL for male and female juvenile rats was 1500 mg/kg/day (about 30 times the human AUC of 24 ng.h/mL after a single oral dose of 100 mg).

8.5       Geriatric Use

Of 1795 IBS-D patients in clinical trials of VIBERZI who received 75 mg or 100 mg twice daily, 139 (7.7%) were at least 65 years of age, while 15 (0.8%) were at least 75 years old. No overall differences in effectiveness were observed between these patients and younger patients. There were no overall differences in the types of adverse reactions observed between elderly and younger patients; however, a higher proportion of elderly patients than younger patients experienced adverse reactions (66% vs 59%), serious adverse reactions (9% vs 4%), and gastrointestinal adverse reactions (39% vs 28%). 

8.6       Hepatic Impairment

Plasma concentrations of eluxadoline increase in patients with hepatic impairment [see Clinical Pharmacology (12.3)].  

VIBERZI is contraindicated in patients with severe hepatic impairment (Child-Pugh Class C) as plasma concentrations of eluxadoline increase significantly (16-fold) and there is no information to support the safety of VIBERZI in these patients.  

In patients with mild (Child-Pugh Class A) or moderate (Child-Pugh Class B) hepatic impairment, plasma concentrations of eluxadoline increase to a lesser extent (6- and 4-fold, respectively). Administer VIBERZI at a reduced dose of 75 mg twice daily to these patients [see Dosage and Administration (2)]. Monitor patients with any degree of hepatic impairment for impaired mental or physical abilities needed to perform potentially hazardous activities such as driving a car or operating machinery and for other eluxadoline-related adverse reactions [see Adverse Reactions (6.1)]. 

8.7       Renal Impairment

In patients with severe renal impairment (eGFR 15 to 30 mL/min/1.73 m2) and ESRD not yet on dialysis (eGFR less than 15 mL/min/1.73 m2), exposure of eluxadoline was increased compared to healthy subjects with normal renal function [see Clinical Pharmacology (12.3)]. Administer VIBERZI at a reduced dose of 75 mg twice daily to patients with moderate or severe renal impairment and in patients with ESRD not yet on dialysis [see Dosage and Administration (2)]. No dosage adjustment is needed for patients with mild renal impairment.

9.1       Controlled Substance

Eluxadoline is listed in Schedule IV of the Controlled Substances Act.

9.2       Abuse

In a drug discrimination study in monkeys, intravenous administration of eluxadoline hydrochloride produced full generalization to the morphine cue.  In a self-administration study in monkeys, eluxadoline hydrochloride was self-administered to a degree that was less than that of heroin but greater than that of saline. 

Adverse reactions of euphoria and feeling drunk were reported in clinical trials of IBS-D evaluating 75 mg and 100 mg doses of VIBERZI. The rate of euphoria was 0% for 75 mg and 0.2% (2/1032) for 100 mg and the rate of feeling drunk was 0.1% (1/807) for 75 mg and 0.1% (1/1032) for 100 mg.

In contrast, in two human abuse potential studies conducted in recreational opioid-experienced individuals, supratherapeutic oral doses of VIBERZI (300 mg and/or 1000 mg) and intranasal doses of VIBERZI (100 mg and/or 200 mg) produced the adverse reaction of euphoria (at a rate ranging from 14% to 28%) that was greater than that of placebo (0% to 5%) but less than that of oxycodone (44% to 76%).  In the two human abuse potential studies, supratherapeutic oral and intranasal doses of VIBERZI produced small but significant increases on positive subjective measures such as Drug Liking and High compared to placebo.  Supratherapeutic oral and intranasal doses of VIBERZI also produced small but significant increases on negative subjective measures such as Drug Disliking and Dysphoria compared to placebo.  In the same studies, oxycodone (30 mg and 60 mg oral, and 15 and 30 mg intranasal) produced significantly greater responses on positive and negative subjective measures than those produced by eluxadoline and placebo.

9.3       Dependence

In studies with monkeys and rats in which eluxadoline and eluxadoline hydrochloride were chronically administered, discontinuation of the drug did not lead to behavioral signs of withdrawal, a measure of physical dependence.  However, the ability of eluxadoline hydrochloride in monkeys to induce self-administration suggests that the drug is sufficiently rewarding to produce reinforcement.  In two human abuse potential studies with VIBERZI conducted in recreational opioid-experienced individuals, euphoria was reported at a rate of 14% to 28%.  These data suggest that eluxadoline may produce psychological dependence.

12.1       Mechanism of Action

Eluxadoline is a mu-opioid receptor agonist; eluxadoline is also a delta opioid receptor antagonist and a kappa opioid receptor agonist. The binding affinities (Ki) of eluxadoline for the human mu and delta opioid receptors are 1.8 nM and 430 nM, respectively. The binding affinity (Ki) of eluxadoline for the human kappa opioid receptor has not been determined; however, the Ki for guinea pig cerebellum kappa opioid receptor is 55 nM. In animals, eluxadoline interacts with opioid receptors in the gut. 

12.2       Pharmacodynamics

Cardiac Electrophysiology

At a dose 10 times the maximum recommended dose (100 mg), VIBERZI does not prolong the QT interval to any clinically relevant extent.

12.3       Pharmacokinetics

Following oral administration of 100 mg VIBERZI in healthy subjects, the Cmax of eluxadoline was approximately 2 to 4 ng/mL and AUC was 12 to 22 ng.h/mL.  Eluxadoline has approximately linear pharmacokinetics with no accumulation upon repeated twice daily dosing. The variability of eluxadoline pharmacokinetic parameters ranges from 51% to 98%.

Absorption

Absolute bioavailability of eluxadoline has not been determined.

Effect of Food

The median Tmax value was 1.5 hours (range: 1 to 8 hours) under fed conditions and 2 hours (range: 0.5 to 6 hours) under fasting conditions [see Dosage and Administration (2)].

The administration of VIBERZI with a high fat meal that contained approximately 800 to 1000 total calories, with 50% of calories being derived from fat content decreased the Cmax of eluxadoline by 50% and AUC by 60%.

Distribution

Plasma protein binding of eluxadoline was 81%.

Elimination

The mean plasma elimination half-life of eluxadoline ranged from 3.7 hours to 6 hours.

Metabolism

 Cytochrome P450 (CYP) and UGT pathways have minimal involvement in the metabolism of eluxadoline. It is unlikely that metabolism of eluxadoline by these enzymes has a clinically meaningful impact on systemic exposure.

Excretion

Following a single oral dose of 300 mg [14C] eluxadoline in healthy male subjects, 82.2% of the total radioactivity was recovered in feces within 336 hours and less than 1% was recovered in urine within 192 hours.

Specific Populations

Patients with Hepatic Impairment

Following a single oral 100–mg dose in subjects with varying degrees of liver impairment and healthy subjects, mean eluxadoline plasma exposure was 6-fold, 4-fold, and 16-fold higher in mild, moderate, and severe hepatically impaired subjects (Child Pugh Class A, B, C), respectively, compared to the subjects with normal liver function [see Dosage and Administration (2), Contraindications (4), Use in Specific Populations (8.6)].

Patients with Renal Impairment

Following a single oral 100 mg dose, the mean eluxadoline Cmax and AUC0-t were 3.7-fold and 4.7-fold higher, respectively, in subjects with severe renal impairment (eGFR 15 to 30 mL/min/1.73 m2, n=2) and 2.4-fold and 5.9-fold higher, respectively, in subjects with ESRD not yet on dialysis (eGFR less than 15 mL/min/1.73 m2, n=6) compared to healthy subjects with normal renal function (n=6) [see Dosage and Administration (2), Use in Specific Populations (8.7)].

Drug Interaction Studies

In Vitro Assessment of Drug Interactions

In vitro studies indicate that eluxadoline is neither an inducer of CYP1A2, CYP2C9, CYP2C19, and CYP3A4, nor an inhibitor of CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2C19, and CYP2D6 at clinically relevant systemic concentrations. Although CYP2E1 was slightly inhibited by eluxadoline (IC50 of approximately 20 micromolar [11 mcg/mL]), clinically meaningful interactions are unlikely. Despite mechanism-based inhibition of CYP3A4 in vitro, eluxadoline did not have a clinically meaningful drug-drug interaction with the CYP3A4 substrate midazolam.

In vitro studies suggest that eluxadoline is a substrate for OAT3, OATP1B1, BSEP and MRP2, but not for OCT1, OCT2, OAT1, OATP1B3, P-gp and BCRP. Based on the in vitro studies, clinically meaningful interaction via inhibition of OCT1, OCT2, OAT1, OAT3, OATP1B3, BSEP and MRP2 by eluxadoline is unlikely.

In Vivo Assessment of Drug Interactions

The following drug interactions were studied in healthy subjects:

Oral Contraceptives

Coadministration of multiple doses of 100 mg VIBERZI with multiple dose administration of an oral contraceptive (norethindrone 0.5 mg/ethinyl estradiol 0.035 mg) does not change the exposure of either drug.

Cyclosporine

Coadministration of a single dose of 100 mg VIBERZI with a single dose of 600 mg cyclosporine resulted in 4.4-fold and 6.2-fold increase in AUC and Cmax of eluxadoline, respectively, compared to administration of VIBERZI alone [see Drug Interactions (7)].

Probenecid

Coadministration of a single dose of 100 mg VIBERZI with a single dose of 500 mg probenecid resulted in a 35% and 31% increase in eluxadoline AUC and Cmax, respectively, compared to administration of VIBERZI alone. This change in eluxadoline exposures is not expected to be clinically meaningful.

Rosuvastatin

Coadministration of multiple doses of 100 mg VIBERZI twice daily with a single dose 20 mg rosuvastatin resulted in an increase in the AUC (40%) and Cmax (18%) of rosuvastatin compared to administration of rosuvastatin alone. Similar results were observed with the active, major metabolite, n-desmethyl rosuvastatin [see Drug Interactions (7)].

Midazolam

Coadministration of multiple doses of 100 mg VIBERZI twice daily with single dose administration of 4 mg midazolam did not affect midazolam pharmacokinetics in humans, suggesting that eluxadoline will not affect the exposure of concomitantly administered CYP3A4 substrates.

13.1       Carcinogenesis, Mutagenesis, Impairment of Fertility

Carcinogenesis

Two-year oral carcinogenicity studies have been conducted with eluxadoline in CD-1 mice at doses up to 1500 mg/kg/day (about 14 times the human AUC of 24 ng.h/mL after a single oral dose of 100 mg) and in Sprague Dawley rats at oral doses up to 1500 mg/kg/day (about 36 times the human AUC of 24 ng.h/mL after a single oral dose of 100 mg). Oral administration of eluxadoline for 104 weeks did not produce tumors in mice and rats.

Mutagenesis

Eluxadoline was negative in the Ames test, chromosome aberration test in human lymphocytes, in the mouse lymphoma cell (L5178Y/TK+/-) forward mutation test and in the in vivo rat bone marrow micronucleus test.

Impairment of Fertility

Eluxadoline at oral doses up to 1000 mg/kg/day (about 10 times the human AUC of 24 ng.h/mL after a single oral dose of 100 mg) was found to have no adverse effect on fertility and reproductive performance of male and female rats.