The safety and efficacy of MOVANTIK were evaluated in two replicate, randomized, double-blind placebo-controlled trials (Study 1 and Study 2) in patients with opioid-induced constipation (OIC) and non-cancer related pain. 

Patients receiving an opioid morphine equivalent daily dose of between 30 mg and 1,000 mg for at least four weeks before enrollment and self-reported OIC were eligible to participate. OIC was confirmed through a two-week run-in period and was defined as <3 spontaneous bowel movements (SBMs) per week on average with at least 25% of the SBMs associated with one or more of the following conditions: (1) straining, (2) hard or lumpy stools; and (3) having a sensation of incomplete evacuation. An SBM was defined as a bowel movement (BM) without rescue laxative taken within the past 24 hours. Patients with 0 BMs over the two-week run-in period or patients with an uneven distribution of SBMs across the two-week run-in period (0 SBMs in one week with ≥4 SBMs in the other week) were excluded. Throughout the studies (including the two-week run-in period), patients were prohibited from using laxatives other than bisacodyl rescue laxative (if they had not had a BM for 72 hours) and one-time use of an enema (if after 3 doses of bisacodyl, they still did not have a BM). 

Patients suspected of having clinically important disruptions to the blood-brain barrier were not enrolled in these studies. 

A total of 652 patients in Study 1 and 700 patients in Study 2 were randomized in a 1:1:1 ratio to receive 12.5 mg or 25 mg of MOVANTIK or placebo once daily for 12 weeks. 

The mean age of the subjects in these two studies was 52 years, 10% and 13% were 65 years of age or older, 61% and 63% were women, and 78% and 80% were White in Studies 1 and 2, respectively. 

Back pain was the most common reason for pain (56% and 57%); arthritis (10% and 10%) and joint pain (3% and 5%) were other prominent reasons in Studies 1 and 2, respectively. Prior to enrollment, patients had been using their current opioid for an average of 3.6 and 3.7 years. The patients who participated in Studies 1 and 2 were taking a wide range of opioids. The mean baseline opioid morphine equivalent daily dosage was 140 mg and 136 mg per day.

Use of one or more laxatives on at least one occasion within the two weeks prior to enrollment was reported by 71% of patients in both Studies 1 and 2. 

The primary endpoint was response defined as: ≥3 SBMs per week and a change from baseline of ≥1 SBM per week for at least 9 out of the 12 study weeks and 3 out of the last 4 weeks.

There was a statistically significant difference for the 25 mg MOVANTIK treatment group versus placebo for the primary endpoint in Study 1 and Study 2 (see Table 3). Statistical significance for the 12.5 mg treatment group versus placebo was observed in Study 1 but not in Study 2 (see Table 3).

One secondary endpoint in Study 1 and Study 2 was response in laxative users with OIC symptoms. This subgroup comprised 55% and 53% of total patients in these two studies, respectively. These patients (identified using an investigator-administered questionnaire), prior to enrollment, had reported using laxative(s) at least 4 out of the past 14 days with at least one of the following OIC symptoms of moderate, severe or very severe intensity: incomplete bowel movements, hard stool, straining, or sensation of needing to pass a bowel movement but unable to do so. In this subgroup, in Studies 1 and 2, 42% and 50% reported using laxatives on a daily basis. The most frequently reported laxatives used on a daily basis were stool softeners (18% and 24%), stimulants (16% and 18%), and polyethylene glycol (6% and 5%). Use of two laxative classes was reported in 31% and 27% anytime during the 14 days prior to enrollment. The most commonly reported combination was stimulants and stool softeners (10% and 8%). In Study 1, a statistically significantly higher percentage of patients in this subgroup responded with MOVANTIK 12.5 mg compared to placebo (43% vs. 29%; p=0.03) and with MOVANTIK 25 mg compared to placebo (49% vs. 29%; p=0.002). In Study 2, a statistically significantly higher percentage of patients in this subgroup responded with MOVANTIK 25 mg compared to placebo (47% vs. 31%; p=0.01). This secondary endpoint was not tested for MOVANTIK 12.5 mg versus placebo in Study 2 because the primary endpoint was not statistically significant.

Another secondary endpoint was time to first post-dose SBM. The time to first post-dose SBM was significantly shorter with MOVANTIK 25 mg compared to placebo in both Study 1 (p <0.001) and Study 2 (p <0.001), and for MOVANTIK 12.5 mg as compared to placebo in Study 1 (p <0.001). For Study 1, the median times to first post-dose SBM were 6, 20, and 36 hours with MOVANTIK 25 mg, MOVANTIK 12.5 mg, and placebo, respectively. For Study 2, the median times to first post-dose SBM were 12 and 37 hours with MOVANTIK 25 mg and placebo, respectively. These analyses do not include the results for MOVANTIK 12.5 mg versus placebo in Study 2 because the primary endpoint was not statistically significant. In the two studies, 61-70% and 58% of patients receiving MOVANTIK 25 mg and MOVANTIK 12.5 mg, respectively, had an SBM within 24 hours of the first dose.

A third secondary endpoint was an evaluation of change from baseline between the treatment groups for mean number of days per week with at least 1 SBM but no more than 3 SBMs. There was a significant difference in number of days per week with 1 to 3 SBMs per day on average over 12 weeks between MOVANTIK 25 mg (Study 1 and Study 2) and MOVANTIK 12.5 mg (Study 1) and placebo.