A Study to Evaluate the Safety and Efficacy of Difelikefalin in Advanced Chronic Kidney Disease Patients With Moderate-to-Severe Pruritus
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ClinicalTrials.gov Identifier: NCT05342623 |
Recruitment Status :
Recruiting
First Posted : April 22, 2022
Last Update Posted : November 22, 2023
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Condition or disease | Intervention/treatment | Phase |
---|---|---|
Chronic Kidney Diseases Pruritus | Drug: Difelikefalin 1 mg Oral Tablet Drug: Placebo Oral Tablet | Phase 3 |
This study will consist of a Screening Period, a 7-day Run-in Period, a 12 week double-blind Efficacy Assessment Phase (Treatment Period 1), a double-blind Long-term Extension Phase (Treatment Period 2) of up to 52 weeks, and a Follow-up Visit (7 to 10 days after the End of Treatment (EOT)/Early Termination (ET) Visit).
If patients continue to meet all inclusion and no exclusion criteria at the end of the 7-day Run-in Period, they will be randomized in a 1:1 ratio to receive once daily oral difelikefalin tablets at a dose of 1 mg or placebo for 12 weeks. Subjects will be stratified according to their use or nonuse of medications to treat pruritus prior to randomization as well as the presence or absence of specific medical conditions. During the Long-term Extension Phase, patients will be re-randomized on Day 1 of Treatment Period 2 to receive either oral difelikefalin 1 mg or placebo, once daily for up to an additional 52 weeks. A final safety Follow-up Visit will be conducted 7 to 10 days after the EOT/ET.
Informed consent will be obtained prior to performing any study-specific procedures. Screening will occur within 7 to 28 days prior to randomization to assess eligibility.
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 400 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Intervention Model Description: | Randomized, double-blind, placebo controlled study |
Masking: | Double (Participant, Investigator) |
Masking Description: | Difelikefalin and placebo will be provided as enteric-coated tablets. All tablets are white in color with no markings and are identical in appearance. Difelikefalin tablets will be provided at doses of 1 mg. |
Primary Purpose: | Treatment |
Official Title: | A Multicenter, Randomized, Double-blind, Placebo-controlled 12-Week Study to Evaluate the Safety and Efficacy of Oral Difelikefalin in Advanced Chronic Kidney Disease Subjects With Moderate-to-Severe Pruritus With an up to 52-Week Long-term Extension |
Actual Study Start Date : | May 17, 2022 |
Estimated Primary Completion Date : | July 2024 |
Estimated Study Completion Date : | October 2024 |

Arm | Intervention/treatment |
---|---|
Experimental: Difelikefalin 1 mg Oral Tablet
Patients receive oral difelikefalin 1 mg once daily
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Drug: Difelikefalin 1 mg Oral Tablet
Difelikefalin 1 mg medication taken orally 1 time/day
Other Name: CR845 |
Placebo Comparator: Placebo Oral Tablet
Patients receive oral placebo once daily
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Drug: Placebo Oral Tablet
Placebo tablet taken orally 1 time/day |
- Efficacy Assessment Phase (Treatment Period 1): Proportion of subjects achieving at least a 4-point improvement from baseline with respect to the weekly mean of the daily 24-hour WI-NRS score at Week 12 of Treatment Period 1 [ Time Frame: Week 12 of Treatment Period 1 ]Intensity of itch will be measured using an NRS used to indicate the intensity of the worst itching over the past 24 hours using a 0 to 10 numeric rating scale, where "0" represents "no itching" and "10" represents "worst itching imaginable".
- Efficacy Assessment Phase (Treatment Period 1): Proportion of subjects achieving at least a 4-point improvement from baseline with respect to the weekly mean of the WI-NRS at Week 8 of Treatment Period 1. [ Time Frame: Week 8 of Treatment Period 1 ]Intensity of itch will be measured using an NRS used to indicate the intensity of the worst itching over the past 24 hours using a 0 to 10 numeric rating scale, where "0" represents "no itching" and "10" represents "worst itching imaginable".
- Efficacy Assessment Phase (Treatment Period 1): Proportion of subjects achieving at least a 4-point improvement from baseline with respect to the weekly mean of the WI-NRS at Week 4 of Treatment Period 1. [ Time Frame: Week 4 of Treatment Period 1 ]Intensity of itch will be measured using an NRS used to indicate the intensity of the worst itching over the past 24 hours using a 0 to 10 numeric rating scale, where "0" represents "no itching" and "10" represents "worst itching imaginable".
- Efficacy Assessment Phase (Treatment Period 1): Proportion of subjects who are "complete itch responders" defined as subjects with ≥ 70% of the non-missing 24-hour WI-NRS scores equal to 0 or 1 at Week 12 of Treatment Period 1. [ Time Frame: Week 12 of Treatment Period 1 ]Intensity of itch will be measured using an NRS used to indicate the intensity of the worst itching over the past 24 hours using a 0 to 10 numeric rating scale, where "0" represents "no itching" and "10" represents "worst itching imaginable".
- Efficacy Assessment Phase (Treatment Period 1): Change from baseline in Sleep Quality Questionnaire score at the end of Week 12 of Treatment Period 1. [ Time Frame: Week 12 of Treatment Period 1 ]Sleep Quality will be measured using an NRS used to indicate how much itch has interfered with sleep during the past 24 hours using a 0 to 10 numeric rating scale, where "0" represents "did not interfere" and "10" represents "completely interfered".

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Ages Eligible for Study: | 18 Years to 85 Years (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
To be eligible for inclusion into the study, a patient must meet the following criteria:
- Advanced stage 4 and 5 CKD and end stage renal disease on hemodialysis
- Subject self-reports experiencing at least near-daily (eg, most days of a week) pruritus for at least 6 months prior to screening.
- Inadequate response to current or prior treatments (including emollients/moisturizers, topical medications, or systemic treatments) for pruritus prior to screening.
Prior to randomization on Day 1 of Treatment Period 1:
- Has recorded at least 4 WI-NRS scores during the 7-day Run-in Period; and
- Has a mean baseline WI-NRS score ≥ 5, defined as the average of all non-missing scores reported during the 7-day Run-in Period.
Exclusion Criteria:
A patient will be excluded from the study if any of the following criteria are met:
- Scheduled to receive a renal replacement therapy (dialysis or kidney transplant) during the study.
- Has a concomitant disease, significant medical condition or physical/laboratory/ECG/vital signs abnormality that, in the opinion of the investigator, puts the subject at undue risk or interferes with interpretation of study results, impedes completion of the study procedures, or compromises the validity of the study measurements.
- New or change of treatment received for itch, including antihistamines and corticosteroids (oral, intravenous, or topical), within 14 days prior to the start of run-in.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT05342623
Contact: Cara Therapeutics | 203-406-3700 | clinicaltrials.gov@caratherapeutics.com |

Study Director: | Frédérique Menzaghi, PhD | Cara Therapeutics |
Responsible Party: | Cara Therapeutics, Inc. |
ClinicalTrials.gov Identifier: | NCT05342623 |
Other Study ID Numbers: |
CR845-310301 |
First Posted: | April 22, 2022 Key Record Dates |
Last Update Posted: | November 22, 2023 |
Last Verified: | November 2023 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Product Manufactured in and Exported from the U.S.: | No |
difelikefalin CR845 Pruritus Chronic Itch Itch Itching uremic pruritus CKD CKD-aP |
CKD-associated pruritus Chronic Kidney Disease Kidney dysfunction Generalized pruritus Hemodialysis Dialysis ESRD (end stage renal disease) Kidney failure, chronic |
Kidney Diseases Renal Insufficiency, Chronic Pruritus Urologic Diseases Female Urogenital Diseases Female Urogenital Diseases and Pregnancy Complications Urogenital Diseases |
Male Urogenital Diseases Renal Insufficiency Chronic Disease Disease Attributes Pathologic Processes Skin Diseases Skin Manifestations |