Prescription Drugs

CLINICAL PHARMACOLOGY Mechanism Of Action Plecanatide is structurally related to human uroguanylin, and similar to uroguanylin, plecanatide functions as a guanylate cyclase-C (GC-C) agonist. Both plecanatide and its active metabolite bind to GC-C and act locally on the luminal surface of the intestinal epithelium. Activation of GC-C results in an increase in both intracellular and extracellular concentrations of cyclic guanosine monophosphate (cGMP). Elevation of intracellular cGMP stimulates secretion of chloride and bicarbonate into the intestinal lumen, mainly through activation of the cystic fibrosis transmembrane conductance regulator (CFTR) ion channel, resulting in increased intestinal fluid and accelerated transit. In animal models, plecanatide has been shown to increase fluid secretion into the gastrointestinal (GI) tract, accelerate intestinal transit, and cause changes in stool consistency. In an animal model of visceral pain, plecanatide reduced abdominal muscle contractions, a measure of intestinal pain. The mechanism has not been studied. Pharmacodynamics Food Effect Subjects who received either a low-fat, low calorie (LF-LC) meal or a high fat, high calorie (HF-HC) meal reported looser stools than fasted subjects up to 24 hours after a single dose of TRULANCE 9 mg (3 times the recommended dose). In clinical studies, TRULANCE was administered with or without food [see DOSAGE AND ADMINISTRATION]. Pharmacokinetics Absorption Plecanatide is minimally absorbed with negligible systemic availability following oral administration. Concentrations of plecanatide and its active metabolite in plasma are below the limit of quantitation after an oral TRULANCE dose of 3 mg. Therefore, standard pharmacokinetic parameters such as AUC, maximum concentration (Cmax), and half-life (t½) cannot be calculated. Food Effect In a crossover study, 24 healthy subjects were given a single dose of TRULANCE 9 mg (3 times the recommended dose) in 3 different states: fasted; following a low-fat, low-calorie meal (LF-LC; approximately 350 calories: 17% from fat, 66% from carbohydrate, and 17% from protein); and following a high-fat, high-calorie meal (HF-HC; approximately 1000 calories: 60% from fat, 25% from carbohydrate, and 15% from protein). Plecanatide was detected in 1 subject (fasted state) at 0.5 and 1 hour post dose. Plecanatide concentrations were below the limit of quantitation for all other time points and for all other subjects. The active metabolite was not detected in any subject. Distribution Given that plecanatide concentrations following clinically relevant oral doses are not measurable, plecanatide is expected to be minimally distributed in tissues. Oral plecanatide is localized to the GI tract where it exerts its effects as a GC-C agonist with negligible systemic exposure. Plecanatide exhibits little to no binding to human serum albumin or human α-1-acid glycoprotein. Elimination Metabolism Plecanatide is metabolized in the GI tract to an active metabolite by loss of the terminal leucine moiety. Both plecanatide and the metabolite are proteolytically degraded within the intestinal lumen to smaller peptides and naturally occurring amino acids. Excretion No excretion studies have been conducted in humans. Plecanatide and its active metabolite are not measurable in plasma following administration of the recommended clinical doses. Drug Interaction Studies Neither plecanatide nor its active metabolite inhibited the cytochrome P450 (CYP) enzymes 2C9 and 3A4, and they did not induce CYP3A4 in vitro. Plecanatide and its active metabolite are neither substrates nor inhibitors of the transporters P-glycoprotein (P-gp) or breast cancer resistance protein (BCRP) in vitro. Clinical Studies The efficacy of TRULANCE for the management of symptoms of CIC was established in two 12-week, double-blind, placebo-controlled, randomized, multicenter clinical studies in adult patients (Study 1 and Study 2). In the Intention-to-Treat (ITT) population, a total of 905 patients (Study 1) and 870 patients (Study 2) were randomized 1:1 to either placebo or TRULANCE 3 mg, once daily. In clinical studies, study medication was administered without respect to food intake. Demographics for these studies included an overall mean age of 45 years (range 18 to 80 years), 80% female, 72% white, and 24% black. To be eligible for the studies, patients were required to meet modified Rome III criteria for at least 3 months prior to the screening visit, with symptom onset for at least 6 months prior to diagnosis. Rome III criteria were modified to require that patients report less than 3 defecations per week, rarely have a loose stool without the use of laxatives, not use manual maneuvers to facilitate defecations, and not meet criteria for IBS-C. In addition, patients were required to report at least two of the following symptoms: Straining during at least 25% of defecations Lumpy or hard stool in at least 25% of defecations Sensation of incomplete evacuations for at least 25% of defecations Sensation of anorectal obstruction/blockage for at least 25% of defecations Patients who met these criteria were also required to demonstrate the following during the last 2 weeks of the screening period: Less than 3 complete spontaneous bowel movements (CSBMs) (a CSBM is an SBM that is associated with a sense of complete evacuation) in each of the two weeks Bristol Stool Form Scale (BSFS) of 6 or 7 in less than 25% of spontaneous bowel movements (SBMs) (an SBM is a bowel movement occurring in the absence of laxative use) One out of the following three: BSFS of 1 or 2 in at least 25% of defecations A straining value recorded on at least 25% of days when a BM was reported At least 25% of BMs result in a sense of incomplete evacuation The efficacy of TRULANCE was assessed using a responder analysis and change-from-baseline in CSBM and SBM endpoints. Efficacy was assessed using information provided by patients on a daily basis in an electronic diary. A responder was defined as a patient who had a least 3 CSBMs in a given week and an increase of at least 1 CSBM from baseline in the same week for at least 9 weeks out of the 12 week treatment period and at least 3 of the last 4 weeks of the study. The responder rates are shown in Table 2. Table 2: Efficacy Responder Rates in the Two Placebo Controlled Studies of CIC: at least 9 of 12 weeks and at least 3 of the last 4 weeks (ITT Population) Study 1 TRULANCE 3 mg N = 453 Placebo N = 452 Treatment Difference# [95% CI*] Responded^ 21% 10% 11% [6.1%, 15.4%] Study 2 TRULANCE 3 mg N = 430 Placebo N = 440 Treatment Difference# [95% CI*] Responded^ 21% 13% 8% [2.6%, 12.4%] * CI = confidence interval ^ primary endpoint defined as a patient who had a least 3 CSBMs in a given week and an increase of at least 1 CSBM from baseline in the same week for at least 9 weeks out of the 12 week treatment period and at least 3 of the last 4 weeks of the study # p-value < 0.005 In both studies, improvements in the frequency of CSBMs/week were seen as early as week 1 with improvement maintained through week 12. The difference between the TRULANCE group and the placebo group in the mean change of CSBMs/week frequency from baseline to week 12 was approximately 1.1 CSBMs/week. Over the 12 week treatment period, improvements were observed in stool frequency (number of CSBMs/week and SBMs/week) and/or stool consistency (as measured by the BSFS), and/or in the amount of straining with bowel movements (amount of time pushing or physical effort to pass stool) in the TRULANCE group as compared to placebo. Following completion of the study drug treatment period, patients continued to record data in the daily diary for a 2 week Post-Treatment Period. During this time, TRULANCE-treated patients generally returned to baseline for these study endpoints. In Studies 1 and 2, a third randomized treatment arm of TRULANCE 6 mg once daily did not demonstrate additional treatment benefit and had a greater incidence of adverse reactions than TRULANCE 3 mg once daily. Therefore, TRULANCE 6 mg once daily is not recommended [see DOSAGE AND ADMINISTRATION].

TRULANCE (plecanatide) Tablets WARNING RISK OF SERIOUS DEHYDRATION IN PEDIATRIC PATIENTS TRULANCE is contraindicated in patients less than 6 years of age; in nonclinical studies in young juvenile mice administration of a single oral dose of plecanatide caused deaths due to dehydration [see CONTRAINDICATIONS, Use in Specific Populations]. Avoid use of TRULANCE in patients 6 years to less than 18 years of age [see WARNINGS AND PRECAUTIONS, Use in Specific Populations]. The safety and effectiveness of TRULANCE have not been established in patients less than 18 years of age [see Use in Specific Populations]. DESCRIPTION TRULANCE (plecanatide) is a guanylate cyclase-C (GC-C) agonist. Plecanatide is a 16 amino acid peptide with the following chemical name: L-Leucine, L-asparaginyl-L-α-aspartyl-L-α-glutamyl-L-cysteinyl-L-αglutamyl-L-leucyl-L-cysteinyl-L-valyl-L-asparaginyl-L-valyl-L-alanyl-L-cysteinyl-L-threonylglycyl-Lcysteinyl-, cyclic (4→12),(7→15)-bis(disulfide). The molecular formula of plecanatide is C65H104N18O26S4 and the molecular weight is 1682 Daltons. The amino acid sequence for plecanatide is shown below: The solid lines linking cysteines illustrate disulfide bridges. Plecanatide is an amorphous, white to off-white powder. It is soluble in water. TRULANCE tablets are supplied as a 3 mg tablet for oral administration. The inactive ingredients are magnesium stearate and microcrystalline cellulose.

INDICATIONS TRULANCE is indicated in adults for the treatment of chronic idiopathic constipation (CIC). DOSAGE AND ADMINISTRATION Recommended Dosage The recommended dosage of TRULANCE is 3 mg taken orally once daily. Preparation And Administration Instructions Take TRULANCE with or without food [see CLINICAL PHARMACOLOGY]. If a dose is missed, skip the missed dose and take the next dose at the regular time. Do not take two doses at the same time. Swallow a tablet whole for each dose. For adult patients with swallowing difficulties, TRULANCE tablets can be crushed and administered orally either in applesauce or with water or administered with water via a nasogastric or gastric feeding tube. Mixing TRULANCE crushed tablets in other soft foods or in other liquids has not been tested. Oral Administration in Applesauce In a clean container, crush the TRULANCE tablet to a powder and mix with 1 teaspoonful of room temperature applesauce. Consume the entire tablet-applesauce mixture immediately. Do not store the mixture for later use. Oral Administration in Water Place the TRULANCE tablet in a clean cup. Pour approximately 30 mL of room temperature water into the cup. Mix by gently swirling the tablet and water mixture for at least 10 seconds. The TRULANCE tablet will fall apart in the water. Swallow the entire contents of the tablet water mixture immediately. If any portion of the tablet is left in the cup, add another 30 mL of water to the cup, swirl for at least 10 seconds, and swallow immediately. Do not store the tablet-water mixture for later use. Administration with Water via a Nasogastric or Gastric Feeding Tube Place the TRULANCE tablet in a clean cup with 30 mL of room temperature water. Mix by gently swirling the tablet and water mixture for at least 15 seconds. The TRULANCE tablet will fall apart in the water. Flush the nasogastric or gastric feeding tube with 30 mL of water using an appropriate syringe. Draw up the mixture using the syringe and immediately administer via the nasogastric or gastric feeding tube. Do not reserve for future use. If any portion of the tablet is left in the cup, add another 30 mL of water to the cup, swirl for at least 15 seconds, and using the same syringe, administer via the nasogastric or gastric feeding tube. Using the same or a fresh syringe, flush the nasogastric or gastric feeding tube with at least 10 mL of water. HOW SUPPLIED Dosage Forms And Strengths TRULANCE Tablets 3 mg: white to off-white, plain, round tablet debossed with “SP” on one side and “3” for 3 mg on the other side. Storage And Handling TRULANCE tablets are packaged in an aluminum foil unit dose blister pack of 30 in a child-resistant pack or in a white, opaque, high-density polyethylene round bottle with a screw-top polypropylene child-resistant cap and heat-activated induction seal. Each bottle container-closure system also contains a desiccant and a polyester coil. TRULANCE 3 mg tablets are white to off-white, plain and round, debossed with “SP” on one side and “3” for 3 mg on the other side and supplied as: NDC Number Size 70194-203-30 Bottle of 30 70194-003-30 Aluminum foil unit dose blister pack of 30 in a child-resistant pack Store at room temperature, 20 to 25°C (68 to 77°F); excursions permitted to 15 to 30°C (59 to 86°F) [see USP Controlled Room Temperature]. Keep TRULANCE in a dry place. Protect from moisture. For bottles, keep TRULANCE in the original bottle. Do not remove desiccant from the bottle. Do not subdivide or repackage. Manufactured for: Synergy Pharmaceuticals Inc. 420 Lexington Avenue, Suite 2012 New York, New York 10170. Revised: Jan 2017

PATIENT INFORMATION TRULANCE™ (troo' lans) (plecanatide) Tablets What is the most important information I should know about TRULANCE? Do not give TRULANCE to children who are less than 6 years of age. It may harm them. You should not give TRULANCE to children 6 years to less than 18 years of age. It may harm them. See “What are the possible side effects of TRULANCE?” for more information about side effects. What is TRULANCE? TRULANCE is a prescription medicine used in adults to treat a type of constipation called chronic idiopathic constipation (CIC). Idiopathic means the cause of the constipation is unknown. It is not known if TRULANCE is safe and effective in children less than 18 years of age. Who should not take TRULANCE? Do not give TRULANCE to children who are less than 6 years of age. Do not take TRULANCE if a doctor has told you that you have a bowel blockage (intestinal obstruction). Before taking TRULANCE, tell your doctor about all of your medical conditions, including if you: are pregnant or plan to become pregnant. It is not known if TRULANCE will harm your unborn baby. are breastfeeding or plan to breastfeed. It is not known if TRULANCE passes into your breast milk. Talk with your doctor about the best way to feed your baby if you take TRULANCE. Tell your doctor about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. How should I take TRULANCE? Take TRULANCE exactly as your doctor tells you to take it. Take TRULANCE by mouth, 1 time each day with or without food. If you miss a dose, skip the missed dose. Take the next dose at your regular time. Do not take 2 doses at the same time. TRULANCE tablets should be swallowed whole. Adults who cannot swallow TRULANCE tablets whole may crush the TRULANCE tablet and mix with applesauce or dissolve TRULANCE in water before swallowing. TRULANCE tablets may also be taken with water by adults through a nasogastric or gastric feeding tube. It is not known if TRULANCE is safe and effective when crushed and mixed with other foods or dissolved in other liquids. Taking TRULANCE in applesauce: Crush the TRULANCE tablet in a clean container until it is a powder and mix with 1 teaspoon of room temperature applesauce. Swallow all of the TRULANCE and applesauce mixture right away. Do not keep the TRULANCE and applesauce mixture for future use. Taking TRULANCE in water: Place the TRULANCE tablet in a clean cup and pour 1 ounce (30 mL) of room temperature water into the cup. Gently swirl the TRULANCE tablet and water for at least 10 seconds. The TRULANCE tablet will fall apart in the water. Swallow all of the TRULANCE tablet and water mixture right away. Do not keep the mixture for future use. If you see any part of the tablet left in the cup, add another 1 ounce (30 mL) of water to the cup, swirl for at least 10 seconds, and swallow right away. Taking TRULANCE through a nasogastric or gastric feeding tube: Gather the supplies you will need to take your TRULANCE dose. Your doctor should tell you what size catheter tipped syringe you will need for your dose. Ask your doctor if you have any questions about how to give TRULANCE the right way. Place the TRULANCE tablet in a clean cup with 1 ounce (30 mL) of room temperature water. Gently swirl the TRULANCE tablet and water for at least 15 seconds. The TRULANCE tablet will fall apart in the water. Flush the nasogastric or gastric feeding tube with 1 ounce (30 mL) of water. Draw up the TRULANCE tablet and water mixture into a catheter tipped syringe and give right away through the nasogastric or gastric feeding tube. Do not keep the mixture for future use. If you see any part of the tablet left in the cup, add another 1 ounce (30 mL) of water to the cup, swirl for at least 15 seconds and use the same catheter tipped syringe to give the mixture through the nasogastric or gastric feeding tube. Using the same or another catheter tipped syringe, flush the nasogastric or gastric feeding tube with at least 10 mL of water. What are the possible side effects of TRULANCE? TRULANCE can cause serious side effects, including: See “What is the most important information I should know about TRULANCE?” Diarrhea is the most common side effect of TRULANCE, and it can sometimes be severe. Diarrhea often begins within the first 4 weeks of TRULANCE treatment. Stop taking TRULANCE and call your doctor if you develop severe diarrhea. These are not all the possible side effects of TRULANCE. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA1088. How should I store TRULANCE? Store TRULANCE at room temperature between 68°F to 77°F (20°C to 25°C). Keep TRULANCE in a secure place and in the bottle or blister pack that it comes in. The TRULANCE bottle contains a desiccant packet to help keep your medicine dry (protect it from moisture). Do not remove the desiccant packet from the bottle. The TRULANCE bottle contains a polyester coil to help protect the tablets during shipping. Remove the polyester coil from the bottle and throw it away when you are ready to start taking TRULANCE. Keep the container of TRULANCE tightly closed and in a dry place. Safely throw away TRULANCE that is out of date or no longer needed. Keep TRULANCE and all medicines out of the reach of children. General information about the safe and effective use of TRULANCE. Medicines are sometimes prescribed for purposes other than those listed in a Medication Guide. Do not use TRULANCE for a condition for which it was not prescribed. Do not give TRULANCE to other people, even if they have the same symptoms that you have. It may harm them. You can ask your doctor or pharmacist for information about TRULANCE that is written for health professionals. What are the ingredients in TRULANCE? Active ingredient: plecanatide Inactive ingredients: magnesium stearate and microcrystalline cellulose

SIDE EFFECTS Clinical Trials Experience Because clinical studies 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. The safety data described below reflect data from 1733 adult patients with CIC randomized in two double-blind, placebo-controlled clinical trials (Study 1 and Study 2) to receive placebo or 3 mg of TRULANCE once daily for 12 weeks. Demographic characteristics were comparable between the TRULANCE and placebo groups [see Clinical Studies]. Most Common Adverse Reactions Table 1 provides the incidence of adverse reactions reported in at least 2% of CIC patients in the TRULANCE-treated group and at an incidence that was greater than in the placebo group. Table 1: Most Common Adverse Reactions* in Two Placebo-Controlled Trials of TRULANCE [Study 1 and Study 2] in Patients with CIC Adverse Reaction TRULANCE, 3 mg (N = 863)% Placebo (N = 870)% Diarrhea 5 1 * reported in at least 2% of TRULANCE-treated patients and at an incidence greater than placebo Diarrhea The majority of reported cases of diarrhea occurred within 4 weeks of treatment initiation. Severe diarrhea was reported in 0.6% of TRULANCE-treated patients compared to 0.3% of placebo-treated patients. Severe diarrhea was reported to occur within the first 3 days of treatment [see WARNINGS AND PRECAUTIONS]. Adverse Reactions Leading To Discontinuation Discontinuations due to adverse reactions occurred in 4% of TRULANCE-treated patients and 2% of placebo-treated patients. The most common adverse reaction leading to discontinuation was diarrhea: 2% of TRULANCE-treated patients and 0.5% of placebo-treated patients withdrew due to diarrhea. Less Common Adverse Reactions Adverse reactions reported in less than 2% of TRULANCE-treated patients and at an incidence greater than placebo were: sinusitis, upper respiratory tract infection, abdominal distension, flatulence, abdominal tenderness, and increased liver biochemical tests (2 patients with alanine aminotransferase (ALT) greater than 5 to 15 times the upper limit of normal and 3 patients with aspartate aminotransferase (AST) greater than 5 times the upper limit of normal). DRUG INTERACTIONS No information provided.

WARNINGS Included as part of the PRECAUTIONS section. PRECAUTIONS Risk Of Serious Dehydration In Pediatric Patients TRULANCE is contraindicated in patients less than 6 years of age. The safety and effectiveness of TRULANCE in patients less than 18 years of age have not been established. In young juvenile mice (human age equivalent of approximately 1 month to less than 2 years), plecanatide increased fluid-secretion into the intestines as a consequence of stimulation of guanylate cyclase-C (GC-C), resulting in mortality in some mice within the first 24 hours, apparently due to dehydration. Due to increased intestinal expression of GC-C, patients less than 6 years of age may be more likely than patients 6 years of age and older to develop severe diarrhea and its potentially serious consequences. Avoid the use of TRULANCE in patients 6 years to less than 18 years of age. Although there were no deaths in older juvenile mice, given the deaths in younger mice and the lack of clinical safety and efficacy data in pediatric patients, avoid the use of TRULANCE in patients 6 years to less than 18 years of age [see CONTRAINDICATIONS, section on Diarrhea below, and Use in Specific Populations]. Diarrhea Diarrhea was the most common adverse reaction in the two placebo-controlled clinical trials. Severe diarrhea was reported in 0.6% of patients [see ADVERSE REACTIONS]. If severe diarrhea occurs, suspend dosing and rehydrate the patient. Patient Counseling Information Advise the patient to read the FDA-approved patient labeling (Medication Guide). Advise Patients: Diarrhea To stop TRULANCE and contact their healthcare provider if they experience severe diarrhea [see WARNINGS AND PRECAUTIONS]. Accidental Ingestion Accidental ingestion of TRULANCE in children, especially in children less than 6 years of age, may result in severe diarrhea and dehydration. Instruct patients to take steps to store TRULANCE securely and out of reach of children and to dispose of unused TRULANCE [see CONTRAINDICATIONS, WARNINGS AND PRECAUTIONS]. Administration And Handling Instructions To take TRULANCE once daily with or without food [see DOSAGE AND ADMINISTRATION]. If a dose is missed, skip the missed dose and take the next dose at the regular time. Do not take two doses at the same time. To swallow TRULANCE tablets whole. If adult patients have swallowing difficulties, TRULANCE tablets can be crushed and administered orally in either applesauce or with water, or administered with water via a nasogastric or gastric feeding tube, as described in the Medication Guide. To keep TRULANCE in a dry place. Protect from moisture. For bottles, keep TRULANCE in the original bottle. Do not remove desiccant from the bottle. Do not subdivide or repackage. Remove and discard polyester coil after opening. Keep bottles closed tightly [see HOW SUPPLIED/Storage and Handling]. Nonclinical Toxicology Carcinogenesis, Mutagenesis, Impairment Of Fertility Carcinogenesis The carcinogenic potential of plecanatide was assessed in 2-year carcinogenicity studies in mice and rats. Plecanatide was not tumorigenic in mice at oral doses up to 90 mg/kg/day or in rats at oral doses up to 100 mg/kg/day. Limited systemic exposure to plecanatide was achieved at the tested dose levels in animals, whereas no detectable exposure occurred in humans. Therefore, animal and human doses should not be compared directly for evaluating relative exposure. Mutagenesis Plecanatide was not genotoxic in the in vitro bacterial reverse mutation (Ames) assay, in vitro mouse lymphoma mutation assay, or the in vivo mouse bone marrow micronucleus assay. Impairment Of Fertility Plecanatide had no effect on fertility or reproductive function in male or female mice at oral doses of up to 600 mg/kg/day. Use In Specific Populations Pregnancy Risk Summary Plecanatide and its active metabolite are negligibly absorbed systemically following oral administration [see CLINICAL PHARMACOLOGY] and maternal use is not expected to result in fetal exposure to the drug. The available data on TRULANCE use in pregnant women are not sufficient to inform any drug-associated risks for major birth defects and miscarriage. In animal developmental studies, no effects on embryo-fetal development were observed with oral administration of plecanatide in mice and rabbits during organogenesis at doses much higher than the recommended human dosage. 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 Pregnant mice and rabbits were administered plecanatide during the period of organogenesis. There was no evidence of harm to embryo-fetal development at oral doses up to 800 mg/kg/day in mice and 250 mg/kg/day in rabbits. Oral administration of up to 600 mg/kg/day in mice 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 0.05 mg/kg/day, based on a 60-kg body weight. Limited systemic exposure to plecanatide was achieved in animals during organogenesis (area under the plasma concentration-time curve [AUCt] = 449 ng•h/mL in rabbits given 250 mg/kg/day). Plecanatide and its active metabolite are not measurable in human plasma following administration of the recommended clinical dosage. Therefore, animal and human doses should not be compared directly for evaluating relative exposure. Lactation Risk Summary There is no information regarding the presence of plecanatide in human milk, or its effects on milk production or the breastfed infant. No lactation studies in animals have been conducted. Plecanatide and its active metabolite are negligibly absorbed systemically following oral administration [see CLINICAL PHARMACOLOGY]. It is unknown whether the negligible systemic absorption of plecanatide by adults will result in a clinically relevant exposure to breastfed infants. Exposure to plecanatide in breastfed infants has the potential for serious adverse effects [see Use in Special Populations]. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for TRULANCE and any potential adverse effects on the breastfed infant from TRULANCE or from the underlying maternal condition. Pediatric Use TRULANCE is contraindicated in pediatric patients less than 6 years of age. Avoid use of TRULANCE in patients 6 years to less than 18 years of age [see CONTRAINDICATIONS, WARNINGS AND PRECAUTIONS]. The safety and effectiveness of TRULANCE in patients less than 18 years of age have not been established. In nonclinical studies, deaths occurred within 24 hours in young juvenile mice (human age equivalent of approximately 1 month to less than 2 years) following oral administration of plecanatide, as described below in Juvenile Animal Toxicity Data. Because of increased intestinal expression of GC-C, patients less than 6 years of age may be more likely than patients 6 years of age and older to develop diarrhea and its potentially serious consequences. TRULANCE is contraindicated in patients less than 6 years of age. Given the deaths in young juvenile mice and the lack of clinical safety and efficacy data in pediatric patients, avoid the use of TRULANCE in patients 6 years to less than 18 years of age. Juvenile Animal Toxicity Data Single oral doses of plecanatide at 0.5 mg/kg and 10 mg/kg caused mortality in young juvenile mice on postnatal days 7 and 14, respectively (human age equivalent of approximately 1 month to less than 2 years). Treatment-related increases in the weight of intestinal contents were observed in juvenile mice following single doses of plecanatide on postnatal day 14 (human age equivalent of approximately less than 2 years), consistent with increased fluid in the intestinal lumen. Although the recommended human dose is approximately 0.05 mg/kg/day, based on a 60-kg body weight, plecanatide and its active metabolite are not measurable in adult human plasma, whereas systemic absorption was demonstrated in the juvenile animal toxicity studies. Animal and human doses should not be compared directly for evaluating relative exposure. Geriatric Use Clinical studies of TRULANCE did not include sufficient numbers of patients aged 65 and over to determine whether they respond differently from patients 18 years to less than 65 years of age. Of 2601 subjects in clinical trials of TRULANCE, 273 (10%) were 65 years of age and over, and 47 (2%) were 75 years and over. 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.