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PAR-101/OPT-80
PAR-101/OPT-80 is a non-systemic antibiotic that binds to bacterial RNA polymerase to inhibit Clostridioides difficile growth in the colon.
PAR-101/OPT-80 is a non-systemic antibiotic that binds to bacterial RNA polymerase to inhibit Clostridioides difficile growth in the colon. Used for Clostridioides difficile infection (CDI), including recurrent CDI.
At a glance
| Generic name | PAR-101/OPT-80 |
|---|---|
| Sponsor | Optimer Pharmaceuticals LLC, a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) |
| Drug class | Non-systemic antibiotic; bacterial RNA polymerase inhibitor |
| Target | Bacterial RNA polymerase (C. difficile) |
| Modality | Small molecule |
| Therapeutic area | Infectious Disease |
| Phase | Phase 3 |
Mechanism of action
OPT-80 is a fidaxomicin analog, a non-absorbed macrocyclic antibiotic that selectively targets bacterial RNA polymerase in C. difficile while minimizing systemic absorption and disruption of normal gut flora. It acts locally in the gastrointestinal tract to eliminate C. difficile while preserving beneficial commensal bacteria, reducing recurrence rates compared to vancomycin.
Approved indications
- Clostridioides difficile infection (CDI), including recurrent CDI
Common side effects
- Nausea
- Vomiting
- Abdominal pain
- Diarrhea
Key clinical trials
- Study to Evaluate the Pharmacokinetics of Fidaxomicin in Inflammatory Bowel Disease (IBD) Subjects With Clostridium Difficile Infection (CDI) (PHASE4)
- A Study to Compare Safety and Efficacy of OPT-80(Fidaxomicin) With Vancomycin in Subjects With Clostridium Difficile-associated Diarrhea (CDAD) (PHASE3)
- A Phase IIIB/IV Study to Compare the Efficacy of Vancomycin Therapy to Extended Duration of Fidaxomicin Therapy in the Clinical Cure of Clostridium Difficile Infection (CDI) in an Older Population (PHASE4)
- A Comparison of Fidaxomicin and Vancomycin in Patients With CDI Receiving Antibiotics for Concurrent Infections (PHASE4)
- Safety, Tolerability, and Pharmacokinetics of Fidaxomicin in Pediatric Subjects With Clostridium Difficile-associated Diarrhea (CDAD) (PHASE2)
- Safety and Efficacy of Fidaxomicin Versus Placebo for Prophylaxis Against Clostridium Difficile-Associated Diarrhea in Adults Undergoing Hematopoietic Stem Cell Transplantation (MK-5119-001) (PHASE3)
- PAR-101/OPT-80 Versus Vancomycin for the Treatment of Clostridium Difficile-Associated Diarrhea (CDAD) (PHASE3)
- Fidaxomicin Versus Vancomycin for the Treatment of Clostridium Difficile-Associated Diarrhea (CDAD) (MK-5119-018) (PHASE3)
Primary sources
Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.
| Source | Used for |
|---|---|
| ClinicalTrials.gov | Trial enrolment, design, endpoints, results |
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