Multiple clinical trials across early- to late-phase development evaluate fidaxomicin for Clostridium difficile infection—including primary, recurrent, and associated diarrhea—as well as in specialized cohorts with inflammatory bowel disease or spinal cord injury. Conducted by academic institutions and pharmaceutical sponsors, these studies investigate parameters such as pharmacokinetics and extended-duration dosing regimens. Protocol statuses across this body of research encompass active recruitment, completion, termination, and withdrawal.
| NCT Number | Recruitment | Conditions | Sponsor/Collaborators | Start Date | Phases |
|---|---|---|---|---|---|
| NCT06794944 | NOT_YET_RECRUITING | Inflammatory Bowel Disease (IBD); Clostridioides Difficile Infection |
Brigham and Women's Hospital |
2026-09 | PHASE4 |
| NCT07328971 | RECRUITING | Clostridia Difficile Colitis |
McGill University Health Centre/Research Institute of the McGill University Health Centre |
2026-04-24 | PHASE3 |
| NCT05266807 | RECRUITING | Clostridioides Difficile Infection |
Benoit Guery |
2023-03-15 | PHASE3 |
| NCT07120490 | NOT_YET_RECRUITING | Clostridioides Difficile Infection; Clostridioides Difficile Infection Recurrence; Fecal Microbiota Transplantation (FMT); Comparative Effectiveness of CDI Treatments; Fidaxomicin; Vancomycin |
Medical University of Warsaw |
2025-10 | |
| NCT02667418 | TERMINATED | Clostridium; Difficile; Fidaxomicin; Vancomycin |
VA Office of Research and Development |
2016-02-19 | PHASE4 |
| NCT05201079 | COMPLETED | Recurrent Clostridium Difficile Infection; Primary Clostridium Difficile Infection |
Mikrobiomik Healthcare Company S.L. |
2021-10-29 | PHASE3 |
| NCT02395848 | TERMINATED | Clostridium Difficile Infection |
McMaster University |
2015-07 | PHASE3 |
| NCT02692651 | COMPLETED | Clostridium Difficile Infection (CDI) |
University of Michigan |
2017-05-01 | PHASE4 |
| NCT04138706 | Recruiting | Clostridium Difficile Infection |
McGill University Health Centre/Research Institute of the McGill University Health Centre|Canadian Institutes of Health Research (CIHR) |
2020-11-19 | Phase 3 |
| NCT03760484 | TERMINATED | Clostridium Difficile |
University of Alberta |
2019-01-21 | PHASE2 |
| NCT02743234 | COMPLETED | Clostridium Difficile Infection |
University of Aarhus |
2016-04 | PHASE3 |
| NCT02464306 | WITHDRAWN | Clostridium Difficile Infection; Solid Organ Transplant |
University of Colorado, Denver |
2018-06 | PHASE4 |
| NCT02218372 | COMPLETED | Clostridium Difficile-associated Diarrhea (CDAD) |
Astellas Pharma Europe B.V. |
2015-01-09 | PHASE3 |
| NCT03053505 | UNKNOWN | Clostridium Difficile Infection |
Sejtterapia Kozpont Kft. |
2017-01 | |
| NCT02057198 | COMPLETED | C. Difficile; Diarrhea; Enterocolitis |
Duke University |
2014-06-10 | PHASE4 |
| NCT02355938 | TERMINATED | Clostridium Difficile; Spinal Cord Injury |
Baylor College of Medicine |
2014-02 | PHASE4 |
| NCT02784002 | COMPLETED | Clostridium Difficile Infection |
Summit Therapeutics |
2014-12 | PHASE2 |
| NCT02437591 | COMPLETED | Inflammatory Bowel Disease (IBD); Clostridium Difficile Infection (CDI) |
Astellas Pharma Europe Ltd. |
2015-08-13 | PHASE4 |
| NCT02254967 | COMPLETED | Clostridium Difficile |
Astellas Pharma Europe Ltd. |
2014-11-06 | PHASE4 |
| NCT02437591 | Completed | Inflammatory Bowel Disease (IBD)|Clostridium Difficile Infection (CDI) |
Astellas Pharma Europe Ltd.|Astellas Pharma Inc |
2015-08-13 | Phase 4 |
| NCT02395848 | Terminated | Clostridium Difficile Infection |
McMaster University |
2015-07 | Phase 3 |
| NCT01691248 | COMPLETED | Clostridium Difficile-Associated Diarrhea (CDAD) |
Optimer Pharmaceuticals LLC, a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) |
2012-10-10 | PHASE3 |
| NCT01818141 | COMPLETED | Clostridium Difficile Infection |
Hartford Hospital |
2012-10-17 | PHASE4 |
| NCT01591863 | COMPLETED | Clostridium Difficile-associated Diarrhea |
Optimer Pharmaceuticals LLC, a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) |
2012-06-15 | PHASE2 |
| NCT01552668 | WITHDRAWN | Clostridium Difficile Infection |
Washington University School of Medicine |
2012-09 | PHASE4 |
| NCT01775397 | TERMINATED | Clostridium Difficile |
Astellas Pharma Europe Ltd. |
2012-11-29 | PHASE4 |
| NCT01813448 | COMPLETED | Pharmacokinetics of Fidaxomicin; Healthy Subjects |
Astellas Pharma Global Development, Inc. |
2013-02 | PHASE1 |
| NCT02083627 | COMPLETED | Drug-Drug Interaction (DDI); Intestinal Absorption; Healthy Subjects; Pharmacokinetics of Rosuvastatin; Pharmacokinetics of Fidaxomicin |
Astellas Pharma Europe B.V. |
2013-02 | PHASE1 |
| NCT00314951 | COMPLETED | Clostridium Infections; Diarrhea |
Optimer Pharmaceuticals LLC, a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) |
2006-05-02 | PHASE3 |
(data from https://clinicaltrials.gov, updated on 2025-11-03)
Check the
Fidaxomicin
product page for in-depth specifications, including solubility, stock solutions, MOA, and working concentrations.
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>).
Note: Technical data last updated: Sep 1, 2026.