TRULANCE Tablet Ref.[10170] Active ingredients: Plecanatide

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 (2.2)].

Absorption

Plecanatide was minimally absorbed with negligible systemic availability following oral administration. Concentrations of plecanatide and its active metabolite in plasma were below the limit of quantitation in the majority of analyzed plasma samples after multiple oral dosing of TRULANCE 3 mg once daily up to 12 weeks. Therefore, standard pharmacokinetic parameters such as AUC, maximum concentration (C_max), and half-life (t_½) could not 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 were not measurable, plecanatide is expected to be minimally distributed in tissues. Oral plecanatide was localized to the GI tract where it exerted its effects as a GC-C agonist with negligible systemic exposure. Plecanatide exhibited little to no binding to human serum albumin or human α-1-acid glycoprotein.

Elimination

Metabolism

Plecanatide was metabolized in the GI tract to an active metabolite by loss of the terminal leucine moiety. Both plecanatide and the metabolite were 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 were 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 were neither substrates nor inhibitors of the transporters P-glycoprotein (P-gp) or breast cancer resistance protein (BCRP) in vitro.

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.

14.1 Chronic Idiopathic Constipation (CIC)

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 defections
• 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 at 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 3.

Table 3. 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):

^a p-value <0.005
^b CI = confidence interval
^c 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.

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 (2.1)].

14.2 Irritable Bowel Syndrome with Constipation (IBS-C)

The efficacy of TRULANCE for the management of symptoms of IBS-C was established in two 12-week, double-blind, placebo-controlled, randomized, multicenter clinical studies in adult patients (Study 3 and Study 4). In the Intention-to-Treat (ITT) population, a total of 699 patients (Study 3) and 754 patients (Study 4) received treatment with 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 44 years (range 18 to 83 years), 74% female, 73% white, and 22% black.

To be eligible, patients were required to meet the Rome III criteria for IBS for at least 3 months prior to the screening visit, with symptom onset for at least 6 months prior to diagnosis. Diagnosis required recurrent abdominal pain or discomfort at least 3 days/month in the last 3 months associated with 2 or more of 1) improvement with defecation, 2) onset associated with a change in frequency of stool, and 3) onset associated with a change in form (appearance) of stool. Patients also met the IBS-C differentiation criteria for constipation, characterized by a stool pattern such that at least 25% of defecations are hard or lumpy stools and no more than 25% of defecations are loose or watery stool.

Patients who met these criteria were excluded if they demonstrated the following during the last 2 weeks of the screening period:

• Worst abdominal pain intensity (WAPI) score of 0 on an 11-point scale for more than 2 days during each week
• An average WAPI of less than 3 for either week
• More than 3 complete spontaneous bowel movements (CSBMs) or more than six spontaneous bowel movements (SBMs) per week in either week
• Bristol Stool Form Scale (BSFS) of 7 for any SBM recorded
• More than 1 day in either week with a BSFS of 6 for any SBM recorded
• No use of rescue laxative (bisacodyl) within 72 hours before randomization

The efficacy of TRULANCE was assessed using a responder analysis based on abdominal pain intensity and a stool frequency responder (CSBM) endpoint. Efficacy was assessed using information provided by patients on a daily basis through an electronic phone diary system.

A responder was defined as a patient who met both the abdominal pain intensity and stool frequency responder criteria in the same week for at least 6 of the 12 treatment weeks. The abdominal pain intensity and stool frequency responder criteria assessed each week were defined as:

• Abdominal pain intensity responder: a patient who experienced a decrease in the weekly average of worst abdominal pain in the past 24 hours score (measured daily) of at least 30% compared with baseline weekly average.
• Stool frequency responder: a patient who experienced an increase of at least 1 CSBM per week from baseline.

The responder rates are shown in Table 4.

Table 4. Efficacy Responder Rates in the Two Placebo-controlled Studies of IBS-C: Overall Responder for at Least 6 of the 12 Treatment Weeks (ITT Population):

^a CI = confidence interval
^b A responder for these trials was defined as a patient who met both the abdominal pain and CSBM weekly responder criteria for at least 6 of the 12 weeks.
^c An abdominal pain responder was defined as a patient who met the criteria of at least 30% reduction from baseline in weekly average of the worst daily abdominal pain, for at least 6 of the 12 weeks.
^d A CSBM responder was defined as a patient who achieved an increase in at least 1 CSBM per week, from baseline, for at least 6 of 12 weeks.

In both studies, the proportion of responders who were also weekly responders for at least 2 of the 4 treatment weeks in month 3, the last month of treatment was greater in the TRULANCE groups compared to placebo.

Over the 12 week treatment period, improvements were observed in both stool consistency (as measured by the BSFS) and in the amount of straining with bowel movements (amount of time pushing or physical effort to pass stool) in the 3 mg 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 3 and 4, a third randomized treatment arm of TRULANCE 6 mg once daily did not demonstrate additional treatment benefit over the 3 mg dose. Therefore, TRULANCE 6 mg once daily is not recommended [see Dosage and Administration (2.1)].