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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

A Phase IIIB/IV Randomized, Controlled, Open-label, Parallel Group Study to Compare the Efficacy of Vancomycin Therapy to Extended Duration Fidaxomicin Therapy in the Sustained Clinical Cure of Clostridium Difficile Infection in an Older Population

Status
Completed
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02254967
Acronym
EXTEND
Enrollment
364
Registered
2014-10-02
Start date
2014-11-06
Completion date
2016-05-05
Last updated
2024-10-31

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Clostridium Difficile

Keywords

Aged, Fidaxomicin, Clostridium Difficile, Vancomycin

Brief summary

The main objective of the study is to evaluate whether the extended duration fidaxomicin therapy is superior to the standard vancomycin therapy in sustained clinical cure of CDI at 30 days after end of treatment (Day 40 or Day 55).

Interventions

DRUGFidaxomicin

oral tablets administered in an extended pulsed regimen

DRUGVancomycin

oral capsule

Sponsors

Merck Sharp & Dohme LLC
CollaboratorINDUSTRY
Astellas Pharma Europe Ltd.
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
60 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* CDI is confirmed by clinical symptoms (either \> 3 unformed bowel movements or ≥ 200ml of unformed stool (for subjects having rectal collection devices)) in the 24 hours prior to randomization and CDI test confirmed positive for presence of C. difficile toxin A or B in stool within 48 hr prior to randomization. * Subject agrees not to participate in another interventional study whilst participating in this study.

Exclusion criteria

* Subject is taking or requiring to be treated with prohibited medications * Subject has received more than one day of dosing of any therapy for CDI within the last 48 hours * Subject has experienced more than 2 previous episodes of CDI in the 3 months prior to study enrolment * Subject is unable to swallow oral study medication. * Subject has a current diagnosis of toxic megacolon. * Subject is not willing to adhere to the provisions of treatment and observation specified in the protocol. * Subject has been randomized into this study previously, has taken any investigational drug within 28 days or 5 half lives, whichever is longer, prior to enrollment, or is currently participating in another clinical study which may influence the assessment of efficacy and/or safety endpoints of this study, in the opinion of the Sponsor. * Subject has previously participated in a CDI vaccine study * Subject has hypersensitivity to fidaxomicin, vancomycin or any of its components.

Design outcomes

Primary

MeasureTime frameDescription
Percentage of Participants with a Sustained Clinical Cure of CDI at 30 Days after End of TreatmentDay 40 (for vancomycin) and day 55 (for fidaxomicin extended pulsed regimen [EPFX])Sustained clinical cure is defined as an assessment of clinical response at test of cure (TOC; day 12 for vancomycin and day 27 or 12 for EPFX arm) and no recurrence of CDI from TOC until time of assessment. Clinical response is determined by the investigator based on the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) criteria at TOC. Treatment response is present when either stool frequency decreases or stool consistency improves and parameters of disease severity (clinical, laboratory, radiological) improves and no new signs of severe disease develops.

Secondary

MeasureTime frameDescription
Percentage of Participants with a Clinical Response of CDI at 2 Days after End of TreatmentDay 12, 27Clinical response is determined by the investigator based on the ESCMID criteria (i.e., Treatment response is present when either stool frequency decreases or stool consistency improves and parameters of disease severity \[clinical, laboratory, radiological\] improves and no new signs of severe disease develops. Treatment response should be daily observed and evaluated after at least three days, assuming that the patient is not worsening on treatment) at TOC.
Percentage of Participants with a Clinical Response of CDI at Day 12Day 12Clinical response is determined by the investigator based on the ESCMID criteria (i.e., Treatment response is present when either stool frequency decreases or stool consistency improves and parameters of disease severity \[clinical, laboratory, radiological\] improves and no new signs of severe disease develops. Treatment response should be daily observed and evaluated after at least three days, assuming that the participant is not worsening on treatment) at TOC.
Number of Participants with a Relapse on Day 90 as Determined by Whole Genome Sequencing of C. Difficile IsolatesBaseline through day 90For participants with a recurrence after TOC, whole genome sequencing of isolates is performed on paired samples from day 1 and the day of the confirmed recurrence. Relapse is defined as paired isolates from a single recurrent participant with ≤ 2 single nucleotide variations (SNVs).
Percentage of Participants with a Sustained Clinical Cure of CDI at Day 40, Day 55 and Day 90Day 40, 55, 90Sustained clinical cure is defined as an assessment of clinical response at test of cure (TOC; day 12 for vancomycin and day 27 or 12 for EPFX arm) and no recurrence of CDI from TOC until time of assessment. Clinical response is determined by the investigator based on the ESCMID criteria at TOC. Treatment response is present when either stool frequency decreases or stool consistency improves and parameters of disease severity (clinical, laboratory, radiological) improves and no new signs of severe disease develops.
Percentage of Participants with a Recurrence of CDI at Day 40, Day 55 and Day 90Day 40, 55, 90For participants with clinical response at TOC, recurrence of CDI is defined as re-establishment of diarrhea after TOC to an extent (judged by the frequency of passed UBMs) that is greater than the frequency recorded on day 10 for vancomycin arm or day 25 for EPFX arm (2 days prior to TOC), confirmed by a CDI test positive for Toxin A/B and requiring further CDI therapy.
Time to Recurrence of CDI after End of Active TreatmentFrom day 10 up to day 90Time to recurrence of CDI is defined as the time in days from clinical response until onset of recurrence of CDI for participants who respond at TOC.
Disease-free Survival After Day 10From day 10 up to day 90Disease-free survival is defined as the time in days a participant does not have symptoms of diarrhea from day 10 up to day 90 for participants who respond at TOC.
Time to Resolution of Diarrhea (TTROD)Up to day 10 (for vancomycin) or up to day 25 (for EPFX)Time to resolution of diarrhea is defined as the time elapsing (in hours rounded up from minutes \> 30) from the start of treatment (time of first dose of study drug) to resolution of diarrhea (time of the last unformed bowel movement \[UBM\] the day prior to the first of 2 consecutive days of ≤ 3 UBMs, \> 50% reduction in number of stools or \> 75% reduction in volume of liquid stool) that are sustained through to TOC.

Countries

Austria, Belgium, Croatia, Czechia, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Poland, Portugal, Romania, Russia, Slovenia, Spain, Sweden, Switzerland, Turkey (Türkiye), United Kingdom

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 8, 2026