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IndexedBuilt automatically from public databases on 2026-09-30. Not yet hand-reviewed by PLOBT.How this works →

Difelikefalin

FDA approved · Rx

Peripheral kappa opioid agonist

Also known as: Korsuva, CR845, CR-845, MR13A9, difelicefalina, difelikefaline, FE-202845

Evidence score
89/ 100
Strong evidence

Strong, human-grade evidence

  • Regulatory standing. FDA-approved prescription medicine
  • Human trials. Backed by controlled human studies
  • Registered human trials. 23 registered studies on ClinicalTrials.gov, most advanced Phase 3
  • 2 cited sources. Includes primary / regulatory sources

Computed with the same four public criteria as every profile. The human-evidence grade on an indexed profile is set automatically and may change when it is hand-reviewed. It is not a safety score, not a purity rating, and not medical advice, and not a claim that this compound treats, cures, or prevents any condition.

What it is

Difelikefalin is a synthetic peptide that activates kappa opioid receptors, sold under the brand name Korsuva. It is designed to act mainly outside the brain, on peripheral nerves and immune cells, which is thought to reduce itch signaling with less central nervous system effect than typical opioids.

What the evidence shows

Automatic summaryHuman trials

It is FDA approved for moderate to severe itch associated with chronic kidney disease in adults on hemodialysis, given intravenously, supported by Phase 3 trials among 23 registered human studies. Its use for other types of itch has been studied but is not established or approved.

Key facts

Molecular formula
C36H53N7O6
Molecular weight
679.8 g/mol
FDA approval
Confirmed on openFDA

Registered human trials

Live from ClinicalTrials.gov, refreshed daily.

23registered studies
Phase 3most advanced phase
15completed (sample)
1recruiting (sample)

A Study Evaluating the Overall Pain Relief and Safety of Intravenous (IV) CR845 in Patients Undergoing Abdominal Surgery

Phase 3CompletedNCT02542384

A Study to Evaluate the Safety and Efficacy of CR845 in Hemodialysis Patients With Moderate-to-Severe Pruritus (KALM-1)

Phase 3CompletedNCT03422653

Difelikefalin for Itching in Hemodialysis Patients With Chronic Kidney Disease

Not Yet RecruitingNCT07526324

A Study to Evaluate the Safety and Efficacy of CR845 in Chronic Kidney Disease Patients With Moderate-to-Severe Pruritus

Phase 2CompletedNCT03617536

Published literature

Live from Europe PMC. This is how much has been published, not how much is proven in humans.

122papers referencing Difelikefalin

A Phase 3 Trial of Difelikefalin in Hemodialysis Patients with Pruritus.

N Engl J Med2020

Treatment of atopic dermatitis: Recently approved drugs and advanced clinical development programs.

Allergy2024

Randomized Controlled Trial of Difelikefalin for Chronic Pruritus in Hemodialysis Patients.

Kidney Int Rep2020

Efficacy of Difelikefalin for the Treatment of Moderate to Severe Pruritus in Hemodialysis Patients: Pooled Analysis of KALM-1 and KALM-2 Phase 3 Studies.

Kidney Med2022

Sources

Risks, side effects and study doses are only published on hand-reviewed profiles. Want this one reviewed, or spotted something wrong? Tell us.