What side effects are associated with this type of intervention?

Common treatments for itching, particularly those similar to Difelikefalin, include opioid antagonists like naltrexone and naloxone. These treatments can cause side effects such as nausea, dizziness, and in some cases, opioid withdrawal-like symptoms. Other systemic treatments for pruritus, such as sertraline (a selective serotonin reuptake inhibitor), may cause side effects including somnolence, dry mouth, and gastrointestinal disturbances. It is important to discuss these potential side effects with a healthcare provider to determine the most appropriate treatment.

What prior FDA approvals exist?

FDA-approved treatments for itching include opioid antagonists such as naltrexone and naloxone, which have been used for pruritus associated with cholestasis. These treatments work by blocking opioid receptors, which can help alleviate itching. Additionally, sertraline, a selective serotonin reuptake inhibitor (SSRI), has been used for cholestatic pruritus. While Difelikefalin is a Kappa Opioid Receptor Agonist, it represents a different mechanism of action compared to these opioid antagonists, focusing on kappa receptors specifically to manage pruritus.

What other types of research exist?

Promising alternatives to Difelikefalin for treating itching include: 1) Sertraline, which has shown long-term efficacy for cholestatic pruritus, 2) Paroxetine, effective in severe non-dermatological pruritus, and 3) Naltrexone, which has been effective in cholestatic pruritus. These treatments have demonstrated efficacy in clinical studies and could be considered as alternatives in 2024.

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Difelikefalin for Itching

Verified Trial

Phase 2 & 3

Recruiting

Research Sponsored by Cara Therapeutics, Inc.

Eligibility Criteria Checklist

Specific guidelines that determine who can or cannot participate in a clinical trial

Must have

Subject has clinically confirmed diagnosis of active Notalgia Paresthetica

Subject has a history of chronic pruritus due to Notalgia Paresthetica

Timeline

Screening 2 weeks

Treatment Varies

Follow Up 2 weeks

Summary

This trial is testing a new oral medication called difelikefalin to see if it can help adults who suffer from severe itching. The medication works by blocking the signals that cause itching. The study will compare different doses to find the most effective one and ensure it is safe for long-term use. Difelikefalin was first approved in the USA for treating severe itching in adults undergoing hemodialysis.

Who is the study for?

This trial is for adults with chronic itching due to Notalgia Paresthetica (NP), who experience moderate to severe pruritus. Participants must not be pregnant or nursing and should have a confirmed diagnosis of active NP. Those with medical conditions that could risk their safety or affect the study's results are excluded.

What is being tested?

The study tests three different doses of oral difelikefalin tablets (0.25 mg, 1.0 mg, and 2.0 mg) against placebo tablets to assess their effectiveness and safety in treating itchiness from NP when taken twice daily.

What are the potential side effects?

While specific side effects for difelikefalin aren't provided here, common ones may include dizziness, headache, dry mouth, nausea, constipation or diarrhea; however individual experiences can vary.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below

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I have been diagnosed with Notalgia Paresthetica.

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I have long-term itching due to Notalgia Paresthetica.

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I often have moderate to severe itching.

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I am not pregnant or breastfeeding.

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I have itching on the upper middle part of my back.

Timeline

Screening ~ 2 weeks2 visits

Treatment ~ Varies

Follow Up ~ 2 weeks0 visits

Screening ~ 2 weeks

Treatment ~ Varies

Follow Up ~2 weeks

This trial's timeline: 2 weeks for screening, Varies for treatment, and 2 weeks for reporting.

Treatment Details

Study Objectives

Study objectives can provide a clearer picture of what you can expect from a treatment.

Primary study objectives

Proportion of subjects achieving ≥4-point improvement from baseline in the weekly mean of the daily 24-hour I-NRS score

Secondary study objectives

Change from Baseline in the Numeric Rating Scale of Burning Sensation and Skin Tingling at Week 8 in Part B

Proportion of Subjects with H-IGA of Clear or Almost Clear at Week 8 in Part B

Proportion of subjects achieving ≥4-point improvement from baseline in the weekly mean of the daily 24-hour I-NRS score at Week 1 in Part B

+3 more

Trial Design

4Treatment groups

Active Control

Placebo Group

Group I: Difelikefalin 0.25 mg tabletsActive Control1 Intervention

Oral difelikefalin 0.25 mg tablet administered twice daily

Group II: Difelikefalin 2.0 mg tabletsActive Control1 Intervention

Oral difelikefalin 2.0 mg tablet administered twice daily

Group III: Difelikefalin 1.0 mg tabletsActive Control1 Intervention

Oral difelikefalin 1.0 mg tablet administered twice daily

Group IV: Placebo tabletsPlacebo Group1 Intervention

Oral placebo tablet administered twice daily

0 / 5Eligibility criteria met

Research Highlights

Information in this section is not a recommendation. We encourage patients to speak with their healthcare team when evaluating any treatment decision.

Mechanism Of Action

Side Effect Profile

Prior Approvals

Other Research

Common treatments for itching, particularly those similar to Difelikefalin, often involve targeting the opioid receptors in the body. Difelikefalin and nalfurafine are kappa opioid receptor agonists, which work by binding to kappa opioid receptors in the nervous system. This binding action helps to modulate the sensation of itch by reducing the transmission of itch signals to the brain. This mechanism is crucial for patients as it directly addresses the neurological pathways responsible for the sensation of itching, providing relief where other treatments may fail. By focusing on these receptors, these treatments can offer significant improvements in quality of life for patients with chronic and severe pruritus.

Efficacy and Safety of Difelikefalin in Japanese Patients With Moderate to Severe Pruritus Receiving Hemodialysis: A Randomized Clinical Trial.Post-marketing surveillance study of the safety and efficacy of nalfurafine hydrochloride (Remitch® capsules 2.5 μg) in 3,762 hemodialysis patients with intractable pruritus.