The safety and effectiveness of naldemedine for opioid-induced constipation in patients with advanced cancer in real-world palliative care settings: a multicenter prospective observational study.

PURPOSE: In this study, we aimed to evaluate the safety and effectiveness of naldemedine for treating opioid-induced constipation (OIC) in patients with advanced cancer, who are receiving palliative care, and particularly explored its early effects. METHODS: Palliative care teams and inpatient palliative care units across 14 institutions in Japan were included in this multicenter, prospective, observational study. Patients who were newly prescribed a daily oral dose of 0.2 mg naldemedine were enrolled. The spontaneous bowel movement (SBM) within 24 h after the first dose of naldemedine was considered the primary outcome, whereas, the secondary outcomes included weekly changes in SBM frequency and adverse events. RESULTS: A total of 204 patients were enrolled and 184 completed the 7-day study. The average age of the participants (103 males, 101 females) was 63 ± 14 years. The primary cancer was detected in the lungs (23.5%), gastrointestinal tract (13.7%), and urological organs (9.3%). A considerable proportion of patients (34.8%) had ECOG performance status of 3-4. Most patients were undergoing active cancer treatment, however, 40.7% of the patients were receiving the best supportive care. Within 24 h of the first naldemedine dose, 146 patients (71.6%, 95% CI: 65.4-77.8%) experienced SBMs. The weekly SBM counts increased in 62.7% of the participants. The major adverse events included diarrhea and abdominal pain, detected in 17.6% and 5.4% of the patients, respectively. However, no serious adverse events were observed. CONCLUSION: Conclusively, naldemedine is effective and safe for OIC treatments in real-world palliative care settings. TRIAL REGISTRATION NUMBER: UMIN000031381, registered 20/02/2018.

A peripherally acting µ-opioid receptor antagonist for treating opioid-associated tinnitus: A case report.

BACKGROUND: The use of opioids occasionally causes tinnitus. However, there is a paucity of data regarding the use of peripherally acting µ-opioid receptor antagonists for opioid-associated tinnitus in patients with cancer. ACTUAL CASE: A 74-year-old male with pancreatic cancer complained of abdominal pain. Two days after initiating oxycodone therapy, the patient experienced tinnitus during body movements. Although peripheral tinnitus disappeared after discontinuing oxycodone, it reappeared with hydromorphone or tapentadol administration. POSSIBLE COURSES OF ACTION: Drug cessation is a preferred intervention for drug-induced tinnitus; however, the cessation of opioids may not be feasible in patients with cancer who are already taking opioids. FORMULATION OF A PLAN: Based on the presumed mechanism of peripheral tinnitus, the use of peripherally acting µ-opioid receptor antagonists was planned, and 200 µg/day of naldemedine was prescribed for tinnitus relief. OUTCOME: Tinnitus disappeared immediately after initiating naldemedine, and the pain was well-controlled. The effect was preserved after increasing or switching opioids. LESSONS: The use of peripherally acting µ-opioid receptor antagonists may be an option to treat opioid-associated tinnitus without compromising the analgesic effects. VIEW: Further clinical data regarding the secondary effect of peripherally acting µ-opioid receptor antagonists on opioid-associated complications other than constipation are required.

A Retrospective Observational Study of Factors Affecting the Efficacy of Concurrent Prescription of Naldemedine for Opioid-Induced Constipation Caused by Oxycodone Tablets.

Naldemedine is indicated for the treatment of opioid-induced constipation (OIC), but reports on its efficacy in preventing OIC are few. Therefore, we retrospectively investigated factors affecting the efficacy of concurrent prescription of naldemedine on OIC. Outpatients with cancer who were started on oxycodone 10 mg/d were included in the study. The eligible patients were classified by their physicians into the following three groups: Group A used regular laxatives before the introduction of oxycodone and initiated naldemedine treatment simultaneously with oxycodone administration, Group B did not take laxatives before the introduction of oxycodone and started naldemedine simultaneously with oxycodone administration, and Group C had been administering regular laxatives before the introduction of oxycodone and were not prescribed naldemedine simultaneously with oxycodone treatment. The Support Team Assessment Schedule Japanese edition score for constipation, frequency of defecation, Bristol Stool Form Scale, sense of incomplete rectal evacuation, and development or worsening of straining to pass bowel movements were compared among the three groups before and after oxycodone administration. In Group B, there was significant worsening of the four parameters except for the sense of incomplete rectal evacuation, whereas Groups A and C did not present any changes. In logistic regression analysis, body weight ≥51.8 kg was a factor significantly decreasing the preventive effect of naldemedine on OIC, and regular use of laxatives was a factor significantly increasing the preventive effect of naldemedine on OIC. Thus, the initiation of naldemedine should be considered depending on the body weight and regular laxative use.

Efficacy of Naldemedine on Intestinal Hypomotility and Adhesions in Rodent Models of Postoperative Ileus.

Postoperative ileus (POI) often decreases patients' QOL because of prolonged hospitalization and readmission. Alvimopan, a peripheral µ-opioid receptor antagonist, is currently the only therapeutic drug for POI. The aim of this study was to examine the efficacy of naldemedine (a peripheral µ-opioid receptor antagonist with a non-competitive pharmacological profile different from that of alvimopan) on postoperative intestinal hypomotility and adhesion in rodent models, and compare it with the effects of alvimopan. Oral administration of naldemedine (0.3 mg/kg) and alvimopan (3 mg/kg) significantly inhibited the decrease in intestinal motility induced by mechanical irritation in mice (p < 0.01, for both). Naldemedine (1 mg/kg) significantly shortened the adhesion length in chemical-induced postoperative adhesion model rats (p < 0.05). Alvimopan (3 mg/kg) also significantly reduced the adhesion ratio (p < 0.01). These findings suggest that naldemedine is effective for postoperative intestinal hypomotility and adhesions in rodents (i.e., as for alvimopan). Thus, naldemedine may be a useful option for the treatment of POI.

Naldemedine-induced opioid withdrawal with restlessness as the predominant symptom in a palliative care setting.

OBJECTIVES: Opioid analgesics play a central role in cancer pain treatment; however, it has been reported that opioid-induced constipation (OIC) develops in 80% of patients using opioid analgesics and leads to a decrease in quality of life. Naldemedine improves constipation without affecting the analgesic action of opioid analgesics via peripheral µ-opioid receptors. METHODS: We report a terminally ill cancer patient who was diagnosed with opioid withdrawal syndrome (OWS) based on symptoms centered around restlessness and sweating that developed 43 days after administration of naldemedine for OIC. RESULTS: The patient was a 78-year-old woman who was diagnosed with stage IVB uterine sarcoma in October, 1 year prior to her visit to our clinic,  and underwent chemotherapy after surgery, but the disease became progressive. Thereafter, metastasis to the fourth thoracic vertebrae (Th4) was identified, and loxoprofen and acetaminophen were started for pain at the metastatic site. Oxycodone hydrochloride hydrate 10 mg/day was additionally administered on postoperative day 11, followed by naldemedine 0.2 mg/day for OIC. On the 43rd day after administration, the patient began to wander the hospital ward in a wheelchair and became noticeably restless. OWS due to naldemedine administration was suspected, and naldemedine was discontinued. The symptoms improved 7 days later, and no similar symptoms were observed thereafter. SIGNIFICANCE OF RESULTS: Patients receiving palliative care often exhibit psychiatric symptoms such as anxiety and depression, but OWS due to naldemedine should also be considered as a potential cause.

A Retrospective Study of the Efficacy and Safety of Naldemedine for Treatment of Opioid-Induced Constipation in Patients with Hepatobiliary Pancreatic Cancer.

Background and Objectives: Opioid analgesics, which are used for cancer-related pain management, cause opioid-induced constipation (OIC). Naldemedine, a peripheral opioid receptor antagonist, is an OIC-modifying agent, but no focused efficacy and safety analysis has been conducted for its use in hepatobiliary pancreatic cancers. We performed a multi-institutional study on the efficacy and safety of naldemedine in patients with hepatobiliary pancreatic cancer using opioids in clinical practice. Materials and Methods: We retrospectively evaluated patients with hepatobiliary pancreatic cancer (including liver, biliary tract, and pancreatic cancers) treated with opioids and naldemedine during hospitalization at ten institutions in Japan from June 2017 to August 2019. We assessed the frequency of bowel movements before and after the initiation of naldemedine therapy. Responders were defined as patients who defecated ≥3 times/week, with an increase from a baseline of ≥1 defecations/week over seven days after the initiation of naldemedine administration. Results: Thirty-four patients were observed for one week before and one week after starting naldemedine. The frequency of bowel movements increased by one over the baseline frequency or to at least thrice per week in 21 patients. The response rate was 61.7% (95% confidence interval: 45.4-78.0%). The median number of weekly bowel movements before and after naldemedine treatment was 2 (range: 0-9) and 6 (range: 1-17), respectively, in the overall population (n = 34); the increase in the number of bowel movements following naldemedine administration was statistically significant (Wilcoxon signed-rank test, p < 0.0001). Diarrhea was the predominant gastrointestinal symptom, and 10 (29.4%) patients experienced grade 1, grade 2, or grade 3 adverse events. The only other adverse event included fatigue in one patient; grade 2-4 adverse events were absent. Conclusions: Naldemedine is effective, and its use may be safe in clinical practice for patients with hepatobiliary pancreatic cancer receiving opioid analgesics.

Establishing Minimal Clinically Important Differences in Quality of Life Measures in Opioid-Induced Constipation.

BACKGROUND & AIMS: Opioids have a role in chronic pain management. However, opioid-induced constipation may cause patients to skip or reduce opioid doses, leading to inadequate pain relief and negatively impacting quality of life. We sought to establish a minimal clinically important difference to understand whether changes in quality of life scores are of value to patients. METHODS: Integrated data from the double-blind, controlled, phase 3 COMPOSE-1 and COMPOSE-2 trials of naldemedine in chronic noncancer pain and opioid-induced constipation were used to determine minimal clinically important differences using Patient Assessment of Constipation Symptoms (PAC-SYM) and Patient Assessment of Constipation Quality of Life (PAC-QOL) questionnaires. Patients completed the questionnaires (5-point Likert scale; predose, Weeks 2, 4, and 12), kept a daily log of Bowel Movement and Constipation Assessment, and rated satisfaction at end of study. Minimal clinically important differences were computed using an anchor-based method with 6 anchors: 5 from the Bowel Movement and Constipation Assessment and 1 from patient satisfaction. Threshold values for each anchor were set to define responders versus nonresponders based on score definitions. Clinically meaningful cutoff values for changes in PAC-SYM and PAC-QOL scores were determined using receiver operating characteristic curves. RESULTS: Data from 1095 patients (549, naldemedine; 546, placebo) were analyzed. The area under the curve for the receiver operating characteristic curves (ranges, 0.719 to 0.798 for PAC-SYM and 0.734 to 0.833 for PAC-QOL) indicated that both instruments can discriminate responders and nonresponders for each anchor. PAC-SYM cutoff values ranged from -1.04 to -0.83; PAC-QOL cutoff values ranged from -0.93 to -0.82. CONCLUSIONS: Based on data derived from the anchor method, reductions in PAC-SYM and PAC-QOL scores of >1.0 in patients with chronic noncancer pain and opioid-induced constipation are clinically meaningful. CLINICALTRIALS: gov Registration: NCT01965158; NCT01993940.

Risk factors for opioid-induced constipation in cancer patients: a single-institution, retrospective analysis.

PURPOSE: To identify risk factors for opioid-induced constipation (OIC). METHODS: This study retrospectively analyzed 175 advanced cancer patients who were receiving pain treatment with opioids and were newly prescribed laxatives for OIC at Seirei Hamamatsu General Hospital between November 2016 and June 2021. For the regression analysis of factors associated with OIC, variables were extracted manually from clinical records. The effect of newly prescribed laxatives for OIC was evaluated as "effective" in cases where the number of spontaneous bowel movements increased at least once in the first 3 days. The OIC was defined based on Rome IV diagnostic criteria. Multivariate logistic regression analysis was performed to identify risk factors for OIC. Optimal cutoff thresholds were determined using receiver operating characteristic analysis. Values of P < 0.05 (two-tailed) were considered significant. RESULTS: Significant factors identified included body mass index (BMI) (odds ratio [OR] = 0.141, 95% confidence interval [CI] = 0.027-0.733; P = 0.020), chemotherapy with taxane within 1 month of evaluation of laxative effect (OR = 0.255, 95% CI = 0.068-0.958; P = 0.043), use of naldemedine (OR = 2.791, 95% CI = 1.220-6.385; P = 0.015), and addition or switching due to insufficient prior laxatives (OR = 0.339, 95% CI = 0.143-0.800; P = 0.014). CONCLUSION: High BMI, chemotherapy including a taxane within 1 month of evaluation of laxative effect, no use of naldemedine, and addition or switching due to insufficient prior laxatives were identified as risk factors for OIC in advanced cancer patients with cancer pain.

Post-marketing surveillance of the safety and effectiveness of naldemedine in the management of opioid-induced constipation in patients with cancer pain in Japan.

PURPOSE: This prospective post-marketing surveillance (PMS) was designed to collect data on the safety and effectiveness of naldemedine in routine clinical practice in patients with opioid-induced constipation (OIC) and cancer pain in Japan and explore the characteristics of patients prone to diarrhea. METHODS: The enrolled patients received naldemedine (0.2 mg, once a day) orally for up to 12 weeks. In the safety analysis, adverse drug reactions (ADRs), including diarrhea as a special interest, were assessed. Effectiveness was evaluated, especially regarding the frequency and condition of bowel movement. RESULTS: In the safety analysis set (n = 1177), 145 ADRs occurred in 133 (11.30%) patients, and diarrhea was the most frequent event (n = 107, 9.09%). Most cases of diarrhea were non-serious (98.1%). Most ADRs were non-serious (93.8%), and they resolved within 2 weeks (75.9%). No patient characteristics influenced the risk of diarrhea development or aggravation. Both the frequency (75.0% and 83.2%) and condition of bowel movement (80.0% and 88.0%) were improved at 2 and 12 weeks, respectively in the effectiveness analysis set (n = 953). Frequency and condition of bowel movement were also improved in patients excluded (e.g., Eastern Cooperative Oncology Group performance status was ≥ 3) or with very small numbers (e.g., received weak opioid) in the clinical trials. CONCLUSIONS: This PMS indicates that naldemedine is well tolerated and effective in patients of various backgrounds in routine clinical practice who have OIC and cancer pain. TRIAL REGISTRATION: UMIN000042851.

A peripheral opioid antagonist for treating urinary retention induced by opioids: A case report.

BACKGROUND: Urinary retention is a poorly studied opioid-related adverse effect. There is a paucity of data regarding the treatment of such disturbance in patients with advanced cancer receiving opioids. ACTUAL CASE: A young man, without comorbidities, was receiving 30 mg/day of oxycodone for abdominal pain due to pancreatic cancer, unsuccessfully. He also complained of severe urinary retention that developed after initiation of opioid therapy. Methadone therapy was effective on pain intensity, but bladder dysfunction persisted. POSSIBLE COURSES OF ACTION: Only anedoctal experience exists for opioid-induced urinary retention. The options included alpha-receptor blockers and flavoxate, which are symptomatic drugs, not addressed to the possible mechanism. FORMULATION OF A PLAN: The use of a peripheral opioid antagonist was planned, according to the presumed mechanism of urinary retention. Thus, naldemedine 200 mcg was prescribed for relieving urinary retention. OUTCOME: The day after starting naldemedine, urinary retention completely reversed and pain was well-controlled. LESSONS: The rational of using naldemedine was based on the component of opioid-induced urinary retention due to involvement of peripheral receptors in the bladder and sphincter. VIEW: In this case report, the effect of the peripheral opioid antagonist was prompt and long-lasting. Future studies of this neglected adverse effect of opioids should be performed to confirm this observation.

Naldemedine-induced opioid withdrawal syndrome with severe psychiatric symptoms in an advanced cervical cancer patient without brain metastasis.

OBJECTIVE: Naldemedine, an oral peripheral µ-opioid receptor antagonist, was developed for the treatment of constipation, a side effect of opioid use. Naldemedine is not generally recognized as causing opioid withdrawal in which associated symptoms affecting the central nervous system. METHOD: From the series of cancer patients undergoing symptom management, we report a case treated with naldemedine for constipation in relation to the use of opioids for cancer pain and who displayed severe psychological symptoms associated with withdrawal immediately after the use of naldemedine. RESULTS: The patient was a 36-year-old woman diagnosed with cervical cancer Stage IIB, PS3. When the patient, who was using oxycodone hydrochloride hydrate (80 mg/day) for ileal pain, was started on naldemedine for constipation, she complained of sweating after just 5 min and hallucinations after 1 h. The patient also displayed physical/behavioral abnormalities such as diarrhea and hyperactivity, and psychological abnormalities such as aggression toward staff.Despite the psychiatric symptoms worsening over time, there were no abnormalities in terms of blood biochemical data, and no brain metastasis was observed on MRI. Based on the Clinical Opiate Withdrawal Scale, these symptoms were judged to indicate opioid withdrawal. Naldemedine was discontinued due to naldemedine-related opioid withdrawal syndrome and, thereafter, the psychiatric symptoms diminished, with no recurrence of similar symptoms observed to date. SIGNIFICANCE OF RESULTS: If mental and behavioral abnormalities occur in patients receiving naldemedine, it is necessary to consider the possibility of opioid withdrawal syndrome as a differential diagnosis.

Opioid withdrawal syndrome developing after long-term administration of naldemedine.

OBJECTIVE: One of the side effects of opioid administration is opioid-induced constipation (OIC). To address this side effect, the oral peripheral µ opioid receptor antagonist naldemedine was developed. As this drug does not cross the blood-brain barrier, it is thought that it does not lead to opioid withdrawal syndrome (OWS) with central nervous system symptoms. METHODS: Here, we report a cancer patient who presented with symptoms centered round anxiety and irritation 4 months after administration of naldemedine for OIC and who was diagnosed with OWS after close investigation. RESULTS: The patient was a 65-year-old female who had surgery for stage IB endometrial cancer 4 years previously, but experienced recurrence involving the pelvis 2 years later. Medical narcotics were used to control pain, but naldemedine was started to control subsequent constipation. When naldemedine-related OWS was suspected and the administration of naldemedine discontinued, the above symptoms disappeared within two days, and no recurrence was observed thereafter. SIGNIFICANCE OF THE RESULTS: For patients receiving naldemedine, it is necessary to consider the possibility of OWS regardless of the period of administration in order to maintain patient quality of life.

Involvement of the Peripheral µ-Opioid Receptor in Tramadol-Induced Constipation in Rodents.

Tramadol is a weak opioid that produces analgesic effect via both the µ-opioid receptor (MOR) and non-opioid targets. Constipation is the most common opioid-related side effect in patients with cancer and non-cancer pain. However, the contribution of MOR to tramadol-induced constipation is unclear. Therefore, we used naldemedine, a peripherally acting MOR antagonist, and MOR-knockout mice to investigate the involvement of peripheral MOR in tramadol-induced constipation using a small intestinal transit model. A single dose of tramadol (3-100 mg/kg, per os (p.o.)) inhibited small intestinal transit dose-dependently in rats. Naldemedine (0.01-10 mg/kg, p.o.) blocked the inhibition of small intestinal transit induced by tramadol (30 mg/kg, p.o.) in rats. The transition rate increased dose-dependently over the range of naldemedine 0.01-0.3 mg/kg, and complete recovery was observed at 0.3-10 m/kg. Additionally, tramadol (30 and 100 mg/kg, subcutaneously (s.c.)) inhibited small intestinal transit in wild-type mice but not in MOR-knockout mice. These results suggest that peripheral MOR participates in tramadol-induced constipation.

Analysis of Predictive Factors for Diarrhea after the Administration of Naldemedine.

Naldemedine (NAL), a peripherally acting µ-opioid receptor antagonist, is effective for opioid-induced constipation (OIC). However, diarrhea is the most common adverse event. We investigated the incidence of NAL-induced diarrhea in patients who started NAL at Nagasaki University Hospital between June 2017 and March 2019. Predictors of NAL-induced diarrhea were analyzed using a multivariate logistic regression model. Two hundred and forty-two patients were included in the present study, and NAL-induced diarrhea was observed in 17.8% (43 patients). The results of multiple logistic regression analyses identified the administration of opioid analgesics for 8 d or longer before the initiation of NAL (odds ratio (OR): 2.20, 95% confidence interval (95% CI): 1.04-4.64, p = 0.039), the combination of a laxative (OR: 2.22, 95%CI: 1.03-4.81, p = 0.042), and the combination of CYP3A4 inhibitors (strong/moderate) (OR: 2.80, 95%CI: 1.02-7.67, p = 0.045) as risk factors. Therefore, the development of diarrhea needs to be considered in patients with these risk factors. Furthermore, diarrhea may be controlled by the initiation of NAL within 7 d of opioid analgesics and, where possible, the discontinuation of or change in the combination of moderate or strong CYP3A4 inhibitors.

Real-World Patient Characteristics and Treatment Patterns of Naldemedine for the Treatment of Opioid-Induced Constipation in Patients with Cancer: A Multicenter Retrospective Chart Review Study.

Background and Objectives: Naldemedine is a peripherally acting µ-opioid receptor antagonist that improves opioid-induced constipation. Although clinical trials have excluded patients with poor performance status (PS) and those started on naldemedine early after opioid initiation, clinical practice has used naldemedine for the same patients. Therefore, we investigated the treatment patterns of naldemedine in a real-world setting. Materials and Methods: This was a multicenter, retrospective chart review study of opioid-treated patients with cancer receiving naldemedine. Adverse events that occurred within 7 days of naldemedine initiation were evaluated in those who received one or more doses of the same. Effectiveness was assessed in patients who used naldemedine for more than 7 days. Results: A total of 296 patients satisfied the eligibility criteria, among whom 129 (43.6%) had a PS of ≥3 and 176 (59.5%) started naldemedine within 2 weeks of opioid initiation. Moreover, 203 (79.6%) patients had ≥3 bowel movements per week. Incidences of all grades of diarrhea and abdominal pain were 87 (29.4%) and 12 (4.1%), respectively. No patient had grade 4 or higher adverse events. Conclusions: Although nearly half of the patients receiving naldemedine in clinical practice belonged to populations that were not included in the clinical trials, our results suggested that naldemedine in clinical practice had the same efficacy and safety as that in clinical trials.

Prevention and management of diarrhea associated with naldemedine among patients receiving opioids: a retrospective cohort study.

BACKGROUND: Naldemedine, a novel peripherally-acting mu-opioid receptor antagonist, has improved opioid-induced constipation in randomized controlled trials. The most frequent adverse event of naldemedine is diarrhea, which can cause abdominal pain and often leads to treatment discontinuation. We aimed to identify risk factors and appropriate management strategies for key adverse events including diarrhea associated with naldemedine, since those have not been extensively studied. METHODS: We conducted a multi-center retrospective cohort study. Eligible patients had cancer, had undergone palliative care at participating centers, had been prescribed regular opioids, and had taken at least one dose of naldemedine between June 2017 and March 2018. The primary endpoint was the incidence of diarrhea according to baseline characteristics. Secondary endpoints included the duration of naldemedine administration, daily defecation counts before and after starting naldemedine, duration and severity of diarrhea as an adverse event of naldemedine, other adverse events, and the incidence of constipation within 7 days after recovery from diarrhea. We defined patients who started naldemedine within three days of starting a regularly prescribed opioid as the early group, and the remainder as the late group. RESULTS: Among 103 patients who received naldemedine, 98 fulfilled the eligibility criteria. The median age was 68 years and 48% of the patients were female. Median performance status was 3, and the median oral intake was 50%. The median duration of naldemedine administration and overall survival were 25 and 64 days, respectively. The incidence of diarrhea in the early group (n = 26) was significantly lower than in the late group (n = 72) (3.9% vs. 22.2%, p = 0.02). Daily defecation counts increased after late (median 0.43 to 0.88, p < 0.001), but remained stable after early naldemedine administration (median 1.00 to 1.00, p = 0.34). Constipation after the diarrhea was resolved was common (53%), especially among patients who stopped naldemedine (78%). The diarrhea was improved within three days in 92% of patients who stopped other laxatives. CONCLUSIONS: The early administration of naldemedine is beneficial because it reduces adverse events including diarrhea. Diarrhea caused by naldemedine can be effectively managed by stopping other laxatives while continuing naldemedine.

A preliminary study of the effect of naldemedine tosylate on opioid-induced nausea and vomiting.

BACKGROUND: Opioid-induced nausea and vomiting (OINV) is induced by opioid receptor stimulation of chemoreceptor trigger zones and vestibular apparatus by opioids. Naldemedine tosylate (NALD) is a peripherally acting non-selective opioid receptor antagonist, used for opioid-induced constipation (OIC). However, the effect of NALD on OINV had not yet been investigated. In this retrospective study, we investigated the secondary effects of NALD on OINV. METHOD: Patients who received sustained-release oral morphine or oxycodone preparation were enrolled in the study. Patients who used NALD (0.2 mg) within 2 days of opioid initiation were included in the analysis. The use of rescue antiemetics within 7 days from opioid initiation was defined as OINV expression. Patients who received antiemetics before opioid initiation or those who received chemotherapy around 4 days from opioid initiation were excluded from the analysis. The incidence of OINV was compared between patients who used and did not use NALD. RESULTS: In total, 982 patients were included in the study. Among them, 89 patients who received NALD and 614 patients who did not receive NALD were analyzed. The incidence of OINV in patients who used NALD was significantly lower than that of patients who did not use NALD (36.0% vs. 47.2%, p = 0.046). CONCLUSION: For patients with constipation, using NALD at an early stage of opioid initiation might have secondary benefits, such as relief from OINV, besides improvement of OIC. To confirm the effectiveness of NALD for OINV, the symptom grade and intensity during concomitant use of NALD should be observed in a future study.

Absorption, distribution, metabolism, and excretion of radiolabeled naldemedine in healthy subjects.

1. Naldemedine is a peripherally acting µ-opioid receptor antagonist for the treatment of opioid-induced constipation. 2. This phase 1 study investigated the absorption, distribution, metabolism and excretion of naldemedine, following a single oral 2-mg dose of [oxadiazole-14C]-naldemedine or [carbonyl-14C]-naldemedine to 12 healthy adult male subjects. Pharmacokinetic assessments were performed on blood, urine and fecal samples collected at defined intervals. 3. Naldemedine was the major circulating component in plasma with a median Tmax of approximately 0.8-0.9 h and a geometric mean t1/2,z of approximately 11 h. Total systemic exposures, AUC, of metabolites nor-naldemedine were less abundant than those of naldemedine (9% or 13% of AUC of naldemedine) and 16.2% or 18.1% of naldemedine was excreted as unchanged in urine after administration of [oxadiazole-14C]-naldemedine or [carbonyl-14C]-naldemedine, respectively, and benzamidine was the major radioactive component after administration of [oxadiazole-14C]-naldemedine (32.5% of administered dose). Overall, the recovery of total radioactivity was 92% (57.3% in urine; 34.8% in feces) after administration of [oxadiazole-14C]-naldemedine and 85% (20.4% in urine; 64.3% in feces) after administration of [carbonyl-14C]-naldemedine. 4. Our findings suggest that naldemedine is mainly metabolized to nor-naldemedine. Naldemedine was rapidly absorbed and well tolerated, with no major safety signals observed.

Randomized phase III and extension studies: efficacy and impacts on quality of life of naldemedine in subjects with opioid-induced constipation and cancer.

BACKGROUND: The efficacy and safety of naldemedine (a peripherally acting µ-opioid receptor antagonist) for opioid-induced constipation (OIC) in subjects with cancer was demonstrated in the primary report of a phase III, double-blind study (COMPOSE-4) and its open-label extension (COMPOSE-5). The primary end point, the proportion of spontaneous bowel movement (SBM) responders, was met. Here, we report results from secondary end points, including quality of life (QOL) assessments from these studies. PATIENTS AND METHODS: In COMPOSE-4, eligible adults with OIC and cancer were randomly assigned 1:1 to receive once-daily oral naldemedine 0.2 mg (n = 97) or placebo (n = 96) for 2 weeks, and those who continued on to COMPOSE-5 received naldemedine for 12 weeks (n = 131). Secondary assessments in COMPOSE-4 included the proportion of complete SBM (CSBM) responders, SBM or CSBM responders by week, and subjects with ≥1 SBM or CSBM within 24 h postinitial dose. Changes from baseline in the frequency of SBMs or CSBMs per week were assessed at weeks 1 and 2. Time to the first SBM or CSBM postinitial dose was also evaluated. In both studies, QOL impact was evaluated by Patient Assessment of Constipation-Symptoms (PAC-SYM) and PAC-QOL questionnaires. RESULTS: Naldemedine improved bowel function for all secondary efficacy assessments versus placebo (all P ≤ 0.0002). The timely onset of naldemedine activity versus placebo was evidenced by median time to the first SBM (4.7 h versus 26.6 h) and CSBM (24.0 h versus 218.5 h) postinitial dose (all P < 0.0001). In COMPOSE-4, significant differences between groups were observed with the PAC-SYM stool domain (P = 0.045) and PAC-QOL dissatisfaction domain (P = 0.015). In COMPOSE-5, significant improvements from baseline were observed for overall and individual domain scores of PAC-SYM and PAC-QOL. CONCLUSIONS: Naldemedine provided effective and timely symptomatic relief from OIC and improved the QOL of subjects with OIC and cancer. TRIAL REGISTRATION ID: www.ClinicalTrials.jp: JAPIC-CTI-132340 (COMPOSE-4) and JAPIC-CTI-132342 (COMPOSE-5).

Population Pharmacokinetics and Exposure-Response Relationships of Naldemedine.

PURPOSE: To characterize population pharmacokinetic (PK) of naldemedine, to identify factors which influence naldemedine PK, and to evaluate their clinical relevancy based on exposure-response relationships. METHODS: A population PK model was developed with pooled naldemedine concentrations from healthy subjects, patients with chronic non-cancer pain and opioid-induced constipation (OIC), and cancer patients with OIC. Exposure-response analyses were performed with efficacy (responder or non-responder) and safety (occurrence of gastrointestinal disorders or not) data in phase 2b and phase 3 studies. RESULTS: Naldemedine plasma concentrations were adequately described by a 2-compartment model with first-order absorption and absorption lag time. The final model included the effects of age, creatinine clearance, race, and gender on apparent total clearance; the effects of body weight, health status, and food condition on apparent volume of central compartment; and the effect of age on first-order rate of absorption. When subjects took 0.2 mg of naldemedine once daily, the probability of spontaneous bowel movement (SBM) responders was predicted to be approximately 50%, while that of severe gastrointestinal disorders was predicted to be less than 3%. The influence of the covariates on PK was not considered clinically significant because similar efficacy and safety were expected based on the exposure-response analysis. CONCLUSIONS: The covariates are identified in the population PK analysis; however, no dose-adjustment is required for them based on the exposure-response analysis.