Linaclotide

5 WARNINGS AND PRECAUTIONS Diarrhea: Patients may experience severe diarrhea. If severe diarrhea occurs, suspend dosing and rehydrate the patient. ( 5.2 ) 5.1 Risk of Serious Dehydration in Pediatric Patients Less Than 2 Years of Age LINZESS is contraindicated in patients less than 2 years of age. In neonatal mice (human age equivalent of approximately 0 to 28 days), linaclotide increased fluid secretion as a consequence of age-dependent elevated GC-C agonism which was associated with increased mortality within the first 24 hours due to dehydration. There was no age-dependent trend in GC-C intestinal expression in a clinical study of children 2 to less than 18 years of age; however, there are insufficient data available on GC-C intestinal expression in children less than 2 years of age to assess the risk of developing diarrhea and its potentially serious consequences in these patients [see Warnings and Precautions ( 5.2 ) and Use in Specific Populations ( 8.4 ) ] . 5. 2 Diarrhea In adults, diarrhea was the most common adverse reaction of LINZESS-treated patients in the pooled IBS-C and CIC double-blind placebo-controlled trials. The incidence of diarrhea was similar between the IBS-C and CIC populations. Severe diarrhea was reported in 2% of adult patients with IBS-C or CIC treated with LINZESS 145 mcg or 290 mcg once daily, and in <1% of adult patients with CIC treated with LINZESS 72 mcg once daily [see Adverse Reactions ( 6.1 )] . In pediatric patients, diarrhea was also the most common adverse reaction in clinical trials of patients 7 to 17 years of age with IBS-C and 6 to 17 years of age with FC treated with LINZESS [see Adverse Reactions ( 6.1 )]. • In a double-blind trial of patients 7 to 17 years of age with IBS-C, diarrhea was reported in 7% and 8% of patients treated with LINZESS 145 mcg and 290 mcg once daily, respectively. One severe case of diarrhea was reported in the IBS-C trial at a dosage higher than the recommended LINZESS 145 mcg once daily dosage for IBS-C. • In a double-blind trial of patients 6 to 17 years of age with FC treated with LINZESS 72 mcg once daily, diarrhea was reported in 4% of patients, and one case of severe diarrhea was reported. In post-marketing experience, severe diarrhea associated with dizziness, syncope, hypotension and electrolyte abnormalities (hypokalemia and hyponatremia) requiring hospitalization or intravenous fluid administration have been reported in patients treated with LINZESS. If severe diarrhea occurs, suspend dosing and rehydrate the patient.

6 ADVERSE REACTIONS Most common adverse reactions (≥2%) reported in adult patients with IBS-C or CIC are: diarrhea, abdominal pain, flatulence and abdominal distension. ( 6.1 ) Most common adverse reaction (≥2%) reported in pediatric patients 7 to 17 years of age with IBS-C and 6 to 17 years of age with FC is diarrhea. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact AbbVie, Inc. at 1-800-633-9110 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in practice. Demographic characteristics were comparable between treatment groups in all studies [see Clinical Studies ( 14.1 , 14.2 , 14.3 , 14.4 , 14.5 )] . Irritable Bowel Syndrome with Constipation (IBS-C) in Adults Most Common Adverse Reactions The data described below reflect exposure to LINZESS in the two placebo-controlled clinical trials involving 1605 adult patients with IBS-C (Trials 1 and 2) [see Clinical Studies ( 14.1 )] . Patients were randomized to receive placebo or 290 mcg LINZESS once daily on an empty stomach for up to 26 weeks. Table 1 provides the incidence of adverse reactions reported in at least 2% of IBS-C patients in the LINZESS treatment group and at an incidence that was greater than in the placebo group. Table 1: Most Common Adverse Reactions a in Two Placebo-Controlled Trials (1 and 2) in Adult Patients with IBS-C Adverse Reactions LINZESS 290 mcg [N=807] % Placebo [N=798] % Gastrointestinal Diarrhea Abdominal pain b Flatulence Abdominal distension 20 7 4 2 3 5 2 1 Infections and Infestations Viral Gastroenteritis 3 1 Nervous System Disorders Headache 4 3 a: Reported in at least 2% of LINZESS-treated patients and at an incidence greater than placebo b: “Abdominal pain” term includes abdominal pain, upper abdominal pain, and lower abdominal pain. Adverse reactions in an additional placebo-controlled trial in 614 IBS-C patients randomized to placebo or LINZESS 290 mcg once daily on an empty stomach for 12 weeks (Trial 6) were similar to those in Table 1. Diarrhea Diarrhea was the most commonly reported adverse reaction of the LINZESS-treated patients in the pooled IBS-C pivotal placebo-controlled trials. In these trials, 20% of LINZESS-treated patients reported diarrhea compared to 3% of placebo-treated patients. Severe diarrhea was reported in 2% of the LINZESS-treated patients versus less than 1% of the placebo-treated patients, and 5% of LINZESS-treated patients discontinued due to diarrhea vs less than 1% of placebo-treated patients. The majority of reported cases of diarrhea started within the first 2 weeks of LINZESS treatment [see Warnings and Precautions ( 5.2 )] . Adverse Reactions Leading to Discontinuation In placebo-controlled trials in patients with IBS-C, 9% of patients treated with LINZESS and 3% of patients treated with placebo discontinued prematurely due to adverse reactions. In the LINZESS-treatment group, the most common reasons for discontinuation due to adverse reactions were diarrhea (5%) and abdominal pain (1%). In comparison, less than 1% of patients in the placebo group withdrew due to diarrhea or abdominal pain. Adverse Reactions Leading to Dose Reductions In the open-label, long-term trials, 2147 patients with IBS-C received 290 mcg of LINZESS daily for up to 18 months. In these trials, 29% of patients had their dose reduced or suspended secondary to adverse reactions, the majority of which were diarrhea or other GI adverse reactions. Less Common Adverse Reactions Defecation urgency, fecal incontinence, vomiting, and gastroesophageal reflux disease were reported in <2% of patients in the LINZESS-treatment group and at an incidence greater than in the placebo treatment group. IBS- C in Pediatric Patients 7 Years of Age and Older The safety of LINZESS 145 mcg once daily was evaluated in 55 pediatric patients 7 to 17 years of age with IBS-C in a 12-week double-blind, parallel-group clinical trial (Trial 8) [see Clinical Studies ( 14.2 )] . The safety profile in pediatric patients treated with LINZESS was similar to the safety profile from trials in adults with IBS-C and CIC and in pediatric patients with FC. Diarrhea was the most common adverse reaction reported in 7% of 145 mcg LINZESS-treated pediatric patients. Most reported cases of diarrhea started within the first 2 weeks of LINZESS treatment [see Warnings and Precautions ( 5.2 )] . Chronic Idiopathic Constipation (CIC) in Adults Most Common Adverse Reactions The data described below reflect exposure to LINZESS in the two double-blind placebo-controlled clinical trials of 1275 adult patients with CIC (Trials 3 and 4) [see Clinical Studies ( 14.3 )] . Patients were randomized to receive placebo or 145 mcg LINZESS or 290 mcg LINZESS once daily on an empty stomach, for at least 12 weeks. Table 2 provides the incidence of adverse reactions reported in at least 2% of CIC patients in the 145 mcg LINZESS treatment group and at an incidence that was greater than in the placebo treatment group. Table 2: Most Common Adverse Reactions a in the Two Placebo-controlled Trials (3 and 4) in Adult Patients with CIC Adverse Reactions LINZESS 145 mcg [N=430] % Placebo [N=423] % Gastrointestinal Diarrhea Abdominal pain b Flatulence Abdominal distension 16 7 6 3 5 6 5 2 Infections and Infestations Upper respiratory tract infection Sinusitis 5 3 4 2 a: Reported in at least 2% of LINZESS-treated patients and at an incidence greater than placebo b: “Abdominal pain” term includes abdominal pain, upper abdominal pain, and lower abdominal pain. The safety of a 72 mcg dose was evaluated in an additional placebo-controlled trial in which 1223 patients were randomized to LINZESS 72 mcg, 145 mcg, or placebo once daily for 12 weeks (Trial 5). In Trial 5, adverse reactions that occurred at a frequency of ≥ 2% in LINZESS-treated patients (N=411 in each LINZESS 72 mcg and 145 mcg group) and at a higher rate than placebo (N=401) were: Diarrhea (LINZESS 72 mcg 19%; LINZESS 145 mcg 22%; placebo 7%) Abdominal distension (LINZESS 72 mcg 2%; LINZESS 145 mcg 1%; placebo < 1%) Diarrhea In Trials 3 and 4 (pooled) and Trial 5, diarrhea was the most commonly reported adverse reaction in LINZESS-treated patients in the CIC placebo-controlled studies. In all trials, the majority of reported cases of diarrhea started within the first 2 weeks of LINZESS treatment. Severe diarrhea was reported in less than 1% of the 72 mcg LINZESS-treated patients (Trial 5), in 2% of the 145 mcg LINZESS-treated patients (Trials 3, 4, and 5), and less than 1% of the placebo-treated patients (Trials 3, 4, and 5) [see Warnings and Precautions ( 5.2 )] . Adverse Reactions Leading to Discontinuation In placebo-controlled trials in patients with CIC, 3% of patients treated with 72 mcg (Trial 5) and between 5% and 8% (Trials 3, 4, and 5) of patients treated with 145 mcg of LINZESS discontinued prematurely due to adverse reactions compared to between less than 1% and 4% (Trials 3, 4, and 5) of patients treated with placebo. In patients treated with 72 mcg LINZESS, the most common reason for discontinuation due to adverse reactions was diarrhea (2% in Trial 5) and, in patients treated with 145 mcg LINZESS, the most common reasons for discontinuation due to adverse reactions were diarrhea (between 3% and 5% in Trials 3, 4, and 5) and abdominal pain (1% in Trials 3 and 4). In comparison, less than 1% of patients in the placebo group withdrew due to diarrhea or abdominal pain (Trials 3, 4, and 5). Adverse Reactions Leading to Dose Reductions In the open-label, long-term trials, 1129 patients with CIC received 290 mcg of LINZESS daily for up to 18 months. In these trials, 27% of patients had their dose reduced or suspended secondary to adverse reactions, the majority of which were diarrhea or other GI adverse reactions. Less Common Adverse Reactions Defecation urgency, fecal incontinence, dyspepsia, and viral gastroenteritis were reported in less than 2% of patients in the LINZESS treatment group and at an incidence greater than in the placebo treatment group. Functional Constipation (FC) Pediatric Patients 6 Years of Age and Older The safety of LINZESS 72 mcg once daily was evaluated in pediatric patients 6 to 17 years of age with FC in a 12-week double-blind, placebo-controlled clinical trial (Trial 7) [see Clinical Studies ( 14.4 )] . There were 164 patients per treatment group. Diarrhea was the most common adverse reaction and was reported in 4% of LINZESS-treated patients compared to 2% of placebo-treated patients. One patient in the LINZESS-treated group reported severe diarrhea and discontinued treatment. No patient in the placebo-treated group discontinued treatment due to severe diarrhea. Most reported cases of diarrhea started within the first 2 weeks of LINZESS treatment [see Warnings and Precautions ( 5.2 )] . Other adverse reactions reported at a higher incidence in the LINZESS group than the placebo group included nausea (2 patients) and abdominal discomfort and dehydration (1 patient each). Pediatric Patients 2 to 5 Years of Age The safety of LINZESS 72 mcg once daily was evaluated in 123 pediatric patients 2 to 5 years of age with FC in a 12-week double-blind, placebo-controlled clinical trial (Trial 9) [see Clinical Studies ( 14.5 )] . One LINZESS-treated patient reported mild diarrhea within the first week of treatment in the trial and the diarrhea resolved while on treatment [see Warnings and Precautions ( 5.2 )] . In general, the safety profile of LINZESS in pediatric patients in this trial was similar to the safety profile from trials in adults with CIC and in older pediatric patients with FC. 6.2 Postmarketing Experience The following adverse reactions have been identified during post approval use of LINZESS. 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 reactions : Anaphylaxis, angioedema, rash (including hives or urticaria) Gastrointestinal reactions: Hematochezia, nausea, rectal hemorrhage

8 USE IN SPECIFIC POPULATIONS 8. 1 Pregnancy Risk Summary Linaclotide and its active metabolite are negligibly absorbed systemically following oral administration [see Clinical Pharmacology ( 12.3 )] , and maternal use is not expected to result in fetal exposure to the drug. The available data on LINZESS use in pregnant women are not sufficient to inform any drug-associated risk for major birth defects and miscarriage. In animal developmental studies, no effects on embryo-fetal development were observed with oral administration of linaclotide in rats and rabbits during organogenesis at doses much higher than the maximum recommended human dosage. Severe maternal toxicity associated with effects on fetal morphology were observed in mice ( see Data ) . The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the United States general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Data Animal Data The potential for linaclotide to cause harm to embryo-fetal development was studied in rats, rabbits and mice. In pregnant mice, oral dose levels of at least 40,000 mcg/kg/day given during organogenesis produced severe maternal toxicity including death, reduction of gravid uterine and fetal weights, and effects on fetal morphology. Oral doses of 5,000 mcg/kg/day did not produce maternal toxicity or any adverse effects on embryo-fetal development in mice. Oral administration of up to 100,000 mcg/kg/day in rats and 40,000 mcg/kg/day in rabbits during organogenesis produced no maternal toxicity and no effects on embryo-fetal development. Additionally, oral administration of up to 100,000 mcg/kg/day in rats during organogenesis through lactation produced no developmental abnormalities or effects on growth, learning and memory, or fertility in the offspring through maturation. The maximum recommended human dose is approximately 5 mcg/kg/day, based on a 60-kg body weight. Limited systemic exposure to linaclotide was achieved in animals during organogenesis (AUC = 40, 640, and 25 ng•hr/mL in rats, rabbits, and mice, respectively, at the highest dose levels). Linaclotide and its active metabolite are not measurable in human plasma following administration of the recommended clinical dosages. Therefore, animal and human doses should not be compared directly for evaluating relative exposure. 8.2 Lactation Risk Summary Linaclotide and its active metabolite were not detected in the milk of lactating women (see Data). In adults, concentrations of linaclotide and its active metabolite were below the limit of quantitation in plasma following multiple doses of LINZESS [see Clinical Pharmacology ( 12.3 ) ] . Maternal use of LINZESS is not expected to result in exposure to linaclotide or its active metabolite in breastfed infants. There is no information on the effects of linaclotide or its active metabolite on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for LINZESS and any potential adverse effects on the breastfed infant from LINZESS or from the underlying maternal condition. Data Following oral administration of 72 mcg, 145 mcg, or 290 mcg of LINZESS once daily for 3 days to breastfeeding mothers taking linaclotide therapeutically, the concentrations of linaclotide and its metabolite were below the limits of quantitation (<0.25 ng/mL and <1 ng/mL, respectively) in all breast milk samples collected over 24 hours. 8.4 Pediatric Use LINZESS is contraindicated in patients less than 2 years of age due to the risk of serious dehydration. In nonclinical studies, deaths occurred within 24 hours in neonatal mice (human age equivalent of approximately 0 to 28 days) following oral administration of linaclotide which increased fluid secretion as a consequence of age-dependent elevated GC-C agonism resulting in rapid and severe dehydration (see Juvenile Animal Toxicity Data ) . In a clinical GC-C ontogeny study in children 6 months to less than 18 years of age (N=99) to measure GC-C mRNA expression levels in duodenal and colonic samples to evaluate the risk of diarrhea and severe dehydration due to GC-C agonism, there was insufficient data on GC-C intestinal expression to assess the risk of developing diarrhea and its potentially serious consequences in children less than 2 years of age [see Warnings and Precautions ( 5.1 )] . Functional Constipation (FC) The safety and effectiveness of LINZESS for the treatment of FC have been established in pediatric patients 2 years of age and older. Use of LINZESS for this indication is supported by evidence from adequate and well-controlled studies in adults and pediatric patients 2 to 17 years of age. The safety of LINZESS in adult and pediatric patients in these clinical studies was similar [see Adverse Reactions ( 6.1 ) and Clinical Studies ( 14.4 , 14.5 )] . The safety and effectiveness of LINZESS for the treatment of FC have not been established in pediatric patients less than 2 years of age. Irritable Bowel Syndrome with Constipation (IBS-C) The safety and effectiveness of LINZESS for the treatment of IBS-C have been established in pediatric patients 7 years of age and older. Use of LINZESS for this indication is supported by evidence from adequate and well-controlled studies in adults and pediatric patients 7 to 17 years of age. The safety of LINZESS in adult and pediatric patients in these clinical studies was similar [see Adverse Reactions ( 6.1 ) and Clinical Studies ( 14.2 )] . The safety and effectiveness of LINZESS for the treatment of IBS-C have not been established in pediatric patients less than 7 years of age. Juvenile Animal Toxicity Data In toxicology studies in neonatal mice, oral administration of linaclotide at 10 mcg/kg/day caused deaths on post-natal day 7 (human age equivalent of approximately 0 to 28 days). These deaths were due to rapid and severe dehydration produced by significant fluid shifts into the intestinal lumen resulting from GC-C agonism in neonatal mice [see Contraindications ( 4 ) and Warnings and Precautions ( 5.1 )] . Tolerability to linaclotide increases with age in juvenile mice. In 2-week-old mice, linaclotide was well tolerated at a dose of 50 mcg/kg/day, but deaths occurred after a single oral dose of 100 mcg/kg. In 3-week-old mice, linaclotide was well tolerated at 100 mcg/kg/day, but deaths occurred after a single oral dose of 600 mcg/kg. 8.5 Geriatric Use Irritable Bowel Syndrome with Constipation (IBS-C) Of 2219 IBS-C patients in the placebo-controlled clinical studies of LINZESS (Trials 1, 2, and 6), 154 (7%) were 65 years of age and over, while 34 (2%) were 75 years and over. Clinical studies of LINZESS did not include sufficient numbers of patients aged 65 years and over to determine whether they respond differently from younger patients. Chronic Idiopathic Constipation (CIC) Of 2498 CIC patients in the placebo-controlled clinical studies of LINZESS (Trials 3, 4, and 5), 273 (11%) were 65 years of age and over, while 56 (2%) were 75 years and over. Clinical studies of LINZESS did not include sufficient numbers of patients aged 65 and over to determine whether they respond differently from younger patients. In general, dose selection for an elderly patient should be cautious reflecting the greater frequency of decreased hepatic, renal or cardiac function and of concomitant disease or other drug therapy.

8. 1 Pregnancy Risk Summary Linaclotide and its active metabolite are negligibly absorbed systemically following oral administration [see Clinical Pharmacology ( 12.3 )] , and maternal use is not expected to result in fetal exposure to the drug. The available data on LINZESS use in pregnant women are not sufficient to inform any drug-associated risk for major birth defects and miscarriage. In animal developmental studies, no effects on embryo-fetal development were observed with oral administration of linaclotide in rats and rabbits during organogenesis at doses much higher than the maximum recommended human dosage. Severe maternal toxicity associated with effects on fetal morphology were observed in mice ( see Data ) . The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the United States general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Data Animal Data The potential for linaclotide to cause harm to embryo-fetal development was studied in rats, rabbits and mice. In pregnant mice, oral dose levels of at least 40,000 mcg/kg/day given during organogenesis produced severe maternal toxicity including death, reduction of gravid uterine and fetal weights, and effects on fetal morphology. Oral doses of 5,000 mcg/kg/day did not produce maternal toxicity or any adverse effects on embryo-fetal development in mice. Oral administration of up to 100,000 mcg/kg/day in rats and 40,000 mcg/kg/day in rabbits during organogenesis produced no maternal toxicity and no effects on embryo-fetal development. Additionally, oral administration of up to 100,000 mcg/kg/day in rats during organogenesis through lactation produced no developmental abnormalities or effects on growth, learning and memory, or fertility in the offspring through maturation. The maximum recommended human dose is approximately 5 mcg/kg/day, based on a 60-kg body weight. Limited systemic exposure to linaclotide was achieved in animals during organogenesis (AUC = 40, 640, and 25 ng•hr/mL in rats, rabbits, and mice, respectively, at the highest dose levels). Linaclotide and its active metabolite are not measurable in human plasma following administration of the recommended clinical dosages. Therefore, animal and human doses should not be compared directly for evaluating relative exposure.

8.4 Pediatric Use LINZESS is contraindicated in patients less than 2 years of age due to the risk of serious dehydration. In nonclinical studies, deaths occurred within 24 hours in neonatal mice (human age equivalent of approximately 0 to 28 days) following oral administration of linaclotide which increased fluid secretion as a consequence of age-dependent elevated GC-C agonism resulting in rapid and severe dehydration (see Juvenile Animal Toxicity Data ) . In a clinical GC-C ontogeny study in children 6 months to less than 18 years of age (N=99) to measure GC-C mRNA expression levels in duodenal and colonic samples to evaluate the risk of diarrhea and severe dehydration due to GC-C agonism, there was insufficient data on GC-C intestinal expression to assess the risk of developing diarrhea and its potentially serious consequences in children less than 2 years of age [see Warnings and Precautions ( 5.1 )] . Functional Constipation (FC) The safety and effectiveness of LINZESS for the treatment of FC have been established in pediatric patients 2 years of age and older. Use of LINZESS for this indication is supported by evidence from adequate and well-controlled studies in adults and pediatric patients 2 to 17 years of age. The safety of LINZESS in adult and pediatric patients in these clinical studies was similar [see Adverse Reactions ( 6.1 ) and Clinical Studies ( 14.4 , 14.5 )] . The safety and effectiveness of LINZESS for the treatment of FC have not been established in pediatric patients less than 2 years of age. Irritable Bowel Syndrome with Constipation (IBS-C) The safety and effectiveness of LINZESS for the treatment of IBS-C have been established in pediatric patients 7 years of age and older. Use of LINZESS for this indication is supported by evidence from adequate and well-controlled studies in adults and pediatric patients 7 to 17 years of age. The safety of LINZESS in adult and pediatric patients in these clinical studies was similar [see Adverse Reactions ( 6.1 ) and Clinical Studies ( 14.2 )] . The safety and effectiveness of LINZESS for the treatment of IBS-C have not been established in pediatric patients less than 7 years of age. Juvenile Animal Toxicity Data In toxicology studies in neonatal mice, oral administration of linaclotide at 10 mcg/kg/day caused deaths on post-natal day 7 (human age equivalent of approximately 0 to 28 days). These deaths were due to rapid and severe dehydration produced by significant fluid shifts into the intestinal lumen resulting from GC-C agonism in neonatal mice [see Contraindications ( 4 ) and Warnings and Precautions ( 5.1 )] . Tolerability to linaclotide increases with age in juvenile mice. In 2-week-old mice, linaclotide was well tolerated at a dose of 50 mcg/kg/day, but deaths occurred after a single oral dose of 100 mcg/kg. In 3-week-old mice, linaclotide was well tolerated at 100 mcg/kg/day, but deaths occurred after a single oral dose of 600 mcg/kg.