Clinical Trials
Difelikefalin has been evaluated across multiple clinical trials spanning Phase 1, Phase 2, and Phase 3 stages to investigate its safety, efficacy, and tolerability. Research primarily focuses on dermatological and nephrological conditions, particularly pruritus associated with chronic kidney disease, end-stage renal disease on hemodialysis, uremic pruritus, atopic dermatitis, and notalgia paresthetica. Studies such as NCT04706975 and NCT05885737 assess both oral and intravenous formulations across diverse patient populations. These investigations are backed by pharmaceutical sponsors including Cara Therapeutics, Inc. and Vifor Fresenius Medical Care Renal Pharma, as well as institutional collaborators like Chittagong Medical College. The current recruitment statuses across these studies reflect a mix of completed, actively recruiting, and terminated protocols.
| NCT Number | Recruitment | Conditions | Sponsor/Collaborators | Start Date | Phases |
|---|---|---|---|---|---|
| NCT06593392 | RECRUITING | Pruritus; Chronic Kidney Diseases |
Vifor Fresenius Medical Care Renal Pharma |
2026-08-04 | PHASE2 |
| NCT07526324 | NOT_YET_RECRUITING | Itching Symptoms; CKD 5D, Hemodialysis |
Chittagong Medical College |
2026-04-26 | |
| NCT05885737 | COMPLETED | Uremic Pruritus |
Vifor Fresenius Medical Care Renal Pharma |
2023-05-18 | PHASE3 |
| NCT05978063 | TERMINATED | Pruritus; Notalgia Paresthetica |
Cara Therapeutics, Inc. |
2023-08-01 | PHASE2; PHASE3 |
| NCT05342623 | TERMINATED | Chronic Kidney Diseases; Pruritus |
Cara Therapeutics, Inc. |
2022-05-17 | PHASE3 |
| NCT05356403 | TERMINATED | Chronic Kidney Diseases; Pruritus |
Cara Therapeutics, Inc. |
2022-08-26 | PHASE3 |
| NCT05387707 | TERMINATED | Pruritus; Atopic Dermatitis |
Cara Therapeutics, Inc. |
2022-08-16 | PHASE3 |
| NCT05885763 | COMPLETED | End Stage Renal Disease on Hemodialysis |
Vifor Fresenius Medical Care Renal Pharma |
2023-06-26 | PHASE1 |
| NCT04706975 | COMPLETED | Pruritus; Notalgia Paresthetica |
Cara Therapeutics, Inc. |
2021-01-11 | PHASE2 |
| NCT04018027 | COMPLETED | Pruritus; Atopic Dermatitis |
Cara Therapeutics, Inc. |
2019-06-29 | PHASE2 |
| NCT05533008 | COMPLETED | Hemodialysis |
Cara Therapeutics, Inc. |
2019-12-31 | PHASE1 |
| NCT04019574 | COMPLETED | Healthy |
Cara Therapeutics, Inc. |
2019-06-20 | PHASE1 |
(data from https://clinicaltrials.gov, updated on 2026-09-01)
Compliance for Clinical Use
Mechanism and Biochemical Profile
Appendix RUO and cGMP Quality Standards
| Quality Dimension | RUO (Research Use Only) | cGMP (Current Good Manufacturing Practice) |
|---|---|---|
| Clinical Applicability | Prohibited in human clinical trials or medical diagnostics. | Mandatory for human clinical trials (Phase I–III) and therapies. |
| Regulatory Status | Non-regulated grade; exempt from drug manufacturing laws. | Legally enforced by health authorities (e.g., FDA, EMA, NMPA). |
| Facility Environment | Unclassified analytical or research laboratories. | Validated Cleanrooms (ISO Class 5–8) with continuous monitoring. |
| Quality Control | Basic purity and activity testing. | Rigorous safety release testing (Sterility, Endotoxin, Mycoplasma). |
| Process Validation | Basic equipment calibration; no process validation required. | Full qualification (IQ/OQ/PQ) and complete batch records. |
| Quality Assurance | Vendor self-declared without required formal QMS. | Mandatory QA/QC unit, Change Control, CAPA, and vendor audits. |
| Regulatory Impact | High risk of IND rejection if used as a critical raw material. | Required for IND/NDA filings, supported by Drug Master Files (DMF). |
Footnotes
Regulatory Note: Governed by FDA (21 CFR Parts 210/211/312), EMA (EudraLex Vol 4), ICH Guidelines (E6/Q7/Q9/Q10), and compendial standards (USP <71>/<85>/<1043>).