Efficacy and Safety of MT-9938 for Treatment of Uremic Pruritus in Subjects With End-stage Renal Disease Receiving Hemodialysis

This study is being conducted to investigate the efficacy of MT-9938 compared with placebo after 2 weeks, to continue to evaluate efficacy for an additional 6 weeks, and to explore the effect of a reduction in itching intensity on health-related Quality of Life(QoL) domains, especially those which recent research suggests have a positive correlation with overall survival for this patient group. The study will consist of the following phases: Screening (1 to 2 weeks), Run in (1 week), double-blind Treatment (8 weeks), Washout (1 week) culminating in a Follow-up Visit (1 week after the last dose).

This study has been terminated because of insufficient patient recruitment. There were no safety concerns.

Eligibility Criteria:
Inclusion Criteria:

* On stable hemodialysis for at least 3 months
* Has stable functioning arteriovenous fistula, graft or other venous access
* Has continued (uncontrolled) uremic pruritus despite standard of care in the institution
* Has severe pruritus, as determined by a qualifying score of ≥3 on the Itch Severity Score Scale (0 to 4) either day or night during the week prior to Screening Visit
* Has no known drug addiction to any prescription, nonprescription, herbal or natural drugs, and successfully passes a drug screen test
* Women and men whose partners are of childbearing potential agree to practice the medically acceptable methods of birth control and agree to continue with the regimen throughout the duration of the study
* Capable of understanding and responding to the subject questionnaires, understands the purpose and risks of the study, and has given written informed consent
* Has rated his/her NRS score each day for at least 5 days out of the 7 days of the Run-in Phase
* Has severe pruritus, as determined by qualifying mean worst NRS score in a day of ≥5 (on 11 point NRS) at the end of the 1-week Run-in Phase

Exclusion Criteria:

* Current, clinically significant medical comorbidities
* Abnormal liver dysfunction
* Pruritus attributed mainly to any disease unrelated to kidney disease
* Calcium x phosphorus product \>80 mg2/dL2 or hemoglobin \<7 g/dL or parathyroid hormone levels \>1000 pg/mL at Screening
* Received ultraviolet B treatment within 30 days prior to Screening
* Started or changed psychotropic medication within 14 days prior to Screening
* Is receiving opioid antagonists or opioid agonists within 7 days prior to Screening and not willing to abstain from these medications during the study.
* Started or changed medications, creams or emollients including over-the-counter oil bath treatment for relief of pruritus within 7 days prior to Screening
* Has known hypersensitivity to opioids or the study drug ingredients
* Is currently participating in an investigational drug or device clinical study or was participating in such a study within 30 days prior to the start of Screening
* Female subject who is known to be pregnant or nursing
* Is considered not suitable for inclusion in the study in the opinion of Investigator
* Has current suicidal ideation with some intent to act or with specific plan and intent or had suicidal behavior at any time in subject's life