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CompletedNCT03595553Ri-CoDIFy 1Updated Oct 9, 2026Results posted

Comparison of Ridinilazole Versus Vancomycin Treatment for Clostridium Difficile Infection

A Phase 3 interventional study of Ridinilazole and Vancomycin in Clostridioides Difficile Infection, sponsored by Summit Therapeutics. Completed at 149 sites in 14 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-09.

Sponsored by Summit Therapeutics · Phase 3, Interventional, and Treatment

Updated Oct 9, 2026Posted results revised35 sites added+1 moreGo to Updates ↓
Phase
Phase 3
Study type
Interventional
Enrollment
759
Allocation
Randomized
Ages
18 Years and older
Sex
All
01

Study summary

Summit is developing ridinilazole as a novel antimicrobial for Clostridioides difficile Infection (CDI), formerly known as Clostridium difficile Infection, with the goal of demonstrating an improved Sustained Clinical Response rate in subjects treated with ridinilazole as compared to subjects treated with vancomycin.

A phase 2 proof of concept study, with vancomycin as comparator, demonstrated these attributes with a comparable safety profile. A high fecal concentration of ridinilazole and little systemic exposure were noted.

The rationale for this phase 3 study is to confirm the improvement in sustained clinical response of CDI over vancomycin and to compare the safety and tolerability of ridinilazole to that of vancomycin.

Ridinilazole plasma concentration will be assessed in a subset of patients.

02

Conditions studied

  • Clostridioides Difficile Infection

Keywords

  • Clostridioides difficile
  • Clostridium difficile
  • C. difficile
  • C. diff
03

In context

Clostridium Infections

251 studies on the registry are indexed under Clostridium Infections; 51 are open to participants now.

This study's enrollment of 759 is above the median of 64 across 185 interventional studies indexed under Clostridium Infections.

Browse Clostridium Infections studies →

Lead sponsor

Summit Therapeutics is the lead sponsor of 13 studies on the registry; 4 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

Patients are eligible to be included in the study only if all the following criteria apply:

  1. Patient must be at least 18 years of age, at the time of signing the .
  2. Have signs and symptoms of CDI including diarrhea such that in the Investigator's opinion, CDI antimicrobial therapy is required. Diarrhea is defined as a change in bowel habits, with ≥3 unformed bowel movements (UBMs) (5, 6 or 7 on the Bristol Stool Chart) in the 24 h prior to randomization.
  3. Have the presence of either toxin A and/or B of C. difficile in the stool determined by a positive free toxin test (using a Sponsor agreed test). The stool sample must be current (produced within 72 hours prior to randomization).

  4. Male or Female

    Male patients:

    • A male patient must agree to use as detailed in Section 10.4 of this protocol during the treatment period and for at least 30 days after the last dose of study treatment and refrain from donating sperm during this period.

    Female patients:

    • A female patient is eligible to participate if she is not pregnant, not breastfeeding, and at least one of the following conditions applies: i. Not a woman of (WOCBP) OR ii. A WOCBP who agrees to follow the contraceptive guidance during the treatment period and for at least 30 days after the last dose of study treatment.
  5. Has provided documented signed informed consent and any authorizations required by local law (e.g. Protected Health Information [PHI]). If unable to read, understand and sign the informed consent form a legally authorized representative (LAR) may provide consent on the patient's behalf if permitted by the Institutional Review Board (IRB)/Ethics Committee (EC).

Exclusion criteria

Exclusion Criteria

Patients are excluded from the study if any of the following criteria apply:

  1. Have had more than one prior episode of CDI in the previous 3 months or more than 3 episodes in the past 12 months prior to randomization.
  2. Have a history of chronic diarrheal disease including inflammatory bowel disease (Crohn's disease or ulcerative colitis).
  3. Have had a positive diagnostic test for other GI pathogens, considered to be , within 2 weeks of randomization.
  4. Have had major gastrointestinal (GI) surgery (e.g. significant bowel resection) within 3 months of randomization (this does not include appendectomy). The presence of a colostomy or ileostomy or likely requirement of an ostomy during the study.
  5. Have life threatening or fulminant CDI with evidence of hypotension, septic shock, peritoneal signs or absence of bowel sounds, or toxic megacolon.
  6. History of bone marrow or hematopoietic stem cell transplant at any time or a known current history of a severely compromised/suppressed immune system that, in the opinion of the Investigator, would make the patient unsuitable for the study.
  7. Have had more than the equivalent of 24 hours of dosing of antimicrobial treatment active against the current episode of CDI prior to randomization. (i.e. more than four doses of oral vancomycin, two doses of fidaxomicin or three doses of metronidazole).
  8. Prior or current use of anti-toxin antibodies including bezlotoxumab within the past 6 months prior to randomization.
  9. Are unable to discontinue products used affecting disease progression at randomization.
  10. Has been involved in a clinical trial and received an medicinal product for indications other than CDI within 1 month or five half-lives (whichever is longer) or within 3 months if the investigational medical product was for CDI.
  11. Have received an investigational vaccine against C. difficile.

  12. Patients that the Investigator feels are inappropriate for the study this would include those;

    1. with any other condition that, in the Investigator's judgment, would make the patient unsuitable for inclusion in the study.
    2. who, in the opinion of the Investigator, are not likely to complete the study for whatever reason, e.g. short .
    3. with known or intolerance to ridinilazole, vancomycin, and/or their
    4. who are unwilling or unable to comply with protocol requirements, e.g. complete the full course of study treatment per schedule, attend study visits, report diarrhea/suspected recurrence, provide stool samples, ingest capsules/tablets or blood draws.
Terms in these criteria, in plain language(8)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

Clinically significant

Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

Life expectancy

The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.

Hypersensitivity

An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.

Excipients

The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.

05

Study design

Phase
Phase 3
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
759 participants (actual)

Study arms

  • Experimental
    ridinilazole

    ridinilazole 200mg bid

    Drug: Ridinilazole

  • Active comparator
    vancomycin

    vancomycin 125 mg qid

    Drug: Vancomycin

Interventions

  • DrugRidinilazole

    ridinilazole (200 mg bid)

    Also known as: 2,2'-di(pyridin-4-yl)-1H,1'H-5,5'-bi(benzimidazole), 2,2'-bis(4-pyridyl)-3H,3'H-5,5'-bibenzimidazole, 2-pyridin-4-yl-6-(2-pyridin-4-yl-3H-benzimidaz

  • DrugVancomycin

    vancomycin (125 mg qid)

06

What researchers measure

Primary outcomes

  1. Number of Participants With Sustained Clinical Response (SCR) Defined as Clinical Response and no Recurrence of CDI Through 30 Days Post End of Treatment (EOT).

    This primary outcome measures the number of participants with Sustained Clinical Response (SCR). SCR is defined as Clinical Response and no recurrence of CDI through 30 days post End of Treatment (EOT). At D40, D70 and D100 the Investigator or medically qualified designee will determine if the patient has a sustained clinical response or experienced RECURRENCE since the previous assessment. The Investigator will assess cure/failure and recurrence based on available information which includes, but is not limited to, improvement from baseline in the number of UBMs, signs \& symptoms of CDI, and the requirement for CDI medication. The Investigator should assess cure/failure in a way that best reflects the Investigator's standard clinical practice.

    Time frame: Day 40

Secondary outcomes

  1. Clinical Response

    defined as * less than 3 unformed bowel movements (UBMs) for consecutive days and maintained through EOT without further CDI treatment at EOT + 2 days, or * the investigator's assessment that the subject no longer needs specific CDI antimicrobial treatment after completion of the course of study medication.

    Time frame: Day 12

  2. Clinical Cure

    defined as the resolution of diarrhea (\<3 UBMs in the 1-day period immediately prior to EOT, that is maintained for 2 days after EOT).

    Time frame: Day 12

  3. Sustained Clinical Response Over 60 Days

    defined as Clinical Response and no recurrence of CDI through 60 days post EOT

    Time frame: Day 70

  4. Sustained Clinical Response Over 90 Days

    defined as Clinical Response and no recurrence of CDI through 90 days post EOT

    Time frame: Day 100

  5. Relative Abundance of the 3 Main Bile Acid Groups (Conjugated Primary, Primary and Secondary Bile Acids) From Baseline to EOT.

    This secondary outcome measures the relative abundance of the 3 main Bile Acid Groups (Conjugated Primary, Primary and Secondary Bile Acids) from Baseline to EOT.

    Time frame: Day 10

  6. Percentage of Change of α-diversity (Shannon Index) of the Microbiota in Stool Samples From Baseline to EOT.

    This secondary outcome measures the percentage of change of α-diversity (Shannon Index) of the microbiota in stool samples from baseline to EOT. Shannon index is a weighted statistic measuring both species richness and evenness. The Shannon Index is calculated by taking the relative abundance of each species and sums the relative abundance times the natural log of the relative abundance for each species. The value is converted into a positive value by times minus one. A higher Shannon Index means higher diversity

    Time frame: Day 10

  7. Measure of β-diversity of the Gut Microbiota Between Baseline and EOT Stool Samples (Bray-Curtis Index/Dissimilarity).

    This secondary outcome measures the β-diversity of the gut microbiota in stool samples from baseline to EOT. Bray-Curtis index/dissimilarity measures how different two samples are in the microbiome composition. The Bray-Curtis dissimilarity is graded between 0 and 1, where 0 means the two samples have the same composition (that is they share all the species and every species has the same abundance), and 1 means the two samples do not share any species.

    Time frame: Day 10

07

Results

Posted Mar 3, 2023

Participant flow

Participant flow — Overall Study
MilestoneRidinilazoleVancomycin
Started370375
Completed312327
Not completed5848
Withdrew: Withdrawal by subject208
Withdrew: Physician decision32
Withdrew: Adverse event25
Withdrew: Death2422
Withdrew: Lost to follow-up67
Withdrew: Other as indicated in csr33
Withdrew: Sponsor decision01

Outcome measures

PrimaryNumber of Participants With Sustained Clinical Response (SCR) Defined as Clinical Response and no Recurrence of CDI Through 30 Days Post End of Treatment (EOT).

This primary outcome measures the number of participants with Sustained Clinical Response (SCR). SCR is defined as Clinical Response and no recurrence of CDI through 30 days post End of Treatment (EOT). At D40, D70 and D100 the Investigator or medically qualified designee will determine if the patient has a sustained clinical response or experienced RECURRENCE since the previous assessment. The Investigator will assess cure/failure and recurrence based on available information which includes, but is not limited to, improvement from baseline in the number of UBMs, signs \& symptoms of CDI, and the requirement for CDI medication. The Investigator should assess cure/failure in a way that best reflects the Investigator's standard clinical practice.

Time frame:
Day 40
Reported as:
Count of participants · Participants
Number of Participants With Sustained Clinical Response (SCR) Defined as Clinical Response and no Recurrence of CDI Through 30 Days Post End of Treatment (EOT).
ParticipantsRidinilazoleVancomycin
SCR based on Clinical Cure238225
SCR based on Clinical Cure Failure132150
SecondaryClinical Response

defined as * less than 3 unformed bowel movements (UBMs) for consecutive days and maintained through EOT without further CDI treatment at EOT + 2 days, or * the investigator's assessment that the subject no longer needs specific CDI antimicrobial treatment after completion of the course of study medication.

Time frame:
Day 12
Reported as:
Count of participants · Participants
Clinical Response
ParticipantsRidinilazoleVancomycin
Clinical Response320346
Clinical Response Failure5029
SecondaryClinical Cure

defined as the resolution of diarrhea (\<3 UBMs in the 1-day period immediately prior to EOT, that is maintained for 2 days after EOT).

Time frame:
Day 12
Reported as:
Count of participants · Participants
Clinical Cure
ParticipantsRidinilazoleVancomycin
Clinical Cure275292
Clinical Cure Failure9583
SecondarySustained Clinical Response Over 60 Days

defined as Clinical Response and no recurrence of CDI through 60 days post EOT

Time frame:
Day 70
Reported as:
Count of participants · Participants
Sustained Clinical Response Over 60 Days
ParticipantsRidinilazoleVancomycin
Sustained Clinical Response 60 Days Post EOT262258
Sustained Clinical Response 60 Days Post EOT Failure108117
SecondarySustained Clinical Response Over 90 Days

defined as Clinical Response and no recurrence of CDI through 90 days post EOT

Time frame:
Day 100
Reported as:
Count of participants · Participants
Sustained Clinical Response Over 90 Days
ParticipantsRidinilazoleVancomycin
Sustained Clinical Response 90 Days Post EOT259249
Sustained Clinical Response 90 Days Post EOT Failure111126
SecondaryRelative Abundance of the 3 Main Bile Acid Groups (Conjugated Primary, Primary and Secondary Bile Acids) From Baseline to EOT.

This secondary outcome measures the relative abundance of the 3 main Bile Acid Groups (Conjugated Primary, Primary and Secondary Bile Acids) from Baseline to EOT.

Time frame:
Day 10
Reported as:
Mean · percentage of abundance
Relative Abundance of the 3 Main Bile Acid Groups (Conjugated Primary, Primary and Secondary Bile Acids) From Baseline to EOT.
percentage of abundanceRidinilazoleVancomycin
Secondary Bile Acid Group at Baseline33.34 ± 35.6830.25 ± 34.13
Secondary Bile Acid Group at EOT38.13 ± 39.637.87 ± 22.69
Primary Bile Acid Group at Baseline55.03 ± 34.0657.44 ± 33.08
Primary Bile Acid Group at EOT55.99 ± 38.0665.72 ± 33.90
Conjugated Primary Bile Acid Group at Baseline11.64 ± 21.9312.31 ± 21.56
Conjugated Primary Bile Acid Group at EOT5.88 ± 15.5026.42 ± 31.62
SecondaryPercentage of Change of α-diversity (Shannon Index) of the Microbiota in Stool Samples From Baseline to EOT.

This secondary outcome measures the percentage of change of α-diversity (Shannon Index) of the microbiota in stool samples from baseline to EOT. Shannon index is a weighted statistic measuring both species richness and evenness. The Shannon Index is calculated by taking the relative abundance of each species and sums the relative abundance times the natural log of the relative abundance for each species. The value is converted into a positive value by times minus one. A higher Shannon Index means higher diversity

Time frame:
Day 10
Reported as:
Mean · percent change in Shannon Index
Percentage of Change of α-diversity (Shannon Index) of the Microbiota in Stool Samples From Baseline to EOT.
percent change in Shannon IndexRidinilazoleVancomycin
Percentage of Change of α-diversity (Shannon Index) of the Microbiota in Stool Samples From Baseline to EOT.37.06 (6.01 to 68.11)-7.32 (-16.61 to 1.97)
SecondaryMeasure of β-diversity of the Gut Microbiota Between Baseline and EOT Stool Samples (Bray-Curtis Index/Dissimilarity).

This secondary outcome measures the β-diversity of the gut microbiota in stool samples from baseline to EOT. Bray-Curtis index/dissimilarity measures how different two samples are in the microbiome composition. The Bray-Curtis dissimilarity is graded between 0 and 1, where 0 means the two samples have the same composition (that is they share all the species and every species has the same abundance), and 1 means the two samples do not share any species.

Time frame:
Day 10
Reported as:
Mean · Bray-Curtis Index
Measure of β-diversity of the Gut Microbiota Between Baseline and EOT Stool Samples (Bray-Curtis Index/Dissimilarity).
Bray-Curtis IndexRidinilazoleVancomycin
Measure of β-diversity of the Gut Microbiota Between Baseline and EOT Stool Samples (Bray-Curtis Index/Dissimilarity).0.7 (0.68 to 0.72)0.81 (0.79 to 0.83)

Adverse events

Collected over All Serious Adverse Events (SAEs) will be collected from the signing of the informed consent form (ICF) until the D100 End of Study visit. All AEs will be collected from the time and date of first dose of study treatment until the D40 follow-up visit.. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
RIDINILAZOLE 200 MG26/374 (7%)32/374 (8.6%)124/374 (33.2%)
VANCOMYCIN 125 MG24/377 (6.4%)30/377 (8%)117/377 (31%)
Most frequent serious events
Showing 10 of 62
Most frequent serious events
EventRIDINILAZOLE 200 MGVANCOMYCIN 125 MG
COVID-19 pneumoniaInfections and infestations3/3743/377
PneumoniaInfections and infestations3/3741/377
UrosepsisInfections and infestations1/3743/377
Clostridium difficile infectionInfections and infestations1/3742/377
Escherichia sepsisInfections and infestations0/3742/377
Pulmonary embolismRespiratory, thoracic and mediastinal disorders1/3742/377
Acute myocardial infarctionCardiac disorders1/3740/377
AsthmaRespiratory, thoracic and mediastinal disorders1/3740/377
Cardiac failureCardiac disorders1/3741/377
Cerebrovascular accidentNervous system disorders1/3740/377
Most frequent other events
Showing 10 of 217
Most frequent other events
EventRIDINILAZOLE 200 MGVANCOMYCIN 125 MG
DiarrhoeaGastrointestinal disorders21/37414/377
NauseaGastrointestinal disorders11/3743/377
HeadacheNervous system disorders5/3749/377
Abdominal painGastrointestinal disorders7/3747/377
HypokalaemiaMetabolism and nutrition disorders7/3743/377
PyrexiaGeneral disorders and administration site conditions7/3743/377
AnaemiaBlood and lymphatic system disorders6/3746/377
HypertensionVascular disorders6/3742/377
ArthralgiaMusculoskeletal and connective tissue disorders1/3746/377
Abdominal pain upperGastrointestinal disorders5/3740/377

Baseline characteristics

Age, Categorical
Age, Categorical(Participants)RidinilazoleVancomycinTotal
<=18 years000
Between 18 and 65 years209213422
>=65 years161162323
Age, Continuous
Age, Continuous(years)RidinilazoleVancomycinTotal
Mean59.1 ± 17.8959.6 ± 17.4259.4 ± 17.64
Sex: Female, Male
Sex: Female, Male(Participants)RidinilazoleVancomycinTotal
Female209227436
Male161148309
Ethnicity (NIH/OMB)
Ethnicity (NIH/OMB)(Participants)RidinilazoleVancomycinTotal
Hispanic or Latino4060100
Not Hispanic or Latino322305627
Unknown or Not Reported81018
Race (NIH/OMB)
Race (NIH/OMB)(Participants)RidinilazoleVancomycinTotal
American Indian or Alaska Native101
Asian111021
Native Hawaiian or Other Pacific Islander000
Black or African American101626
White333331664
More than one race8816
Unknown or Not Reported71017
Region of Enrollment
Region of Enrollment(participants)RidinilazoleVancomycinTotal
United States8187168
Canada121729
Europe229220449
Mexico51116
Brazil31013
Chile235
Argentina101
Peru101
Israel171532
South Korea10919
Australia628
New Zealand314
BMI
BMI(kg/m^2)RidinilazoleVancomycinTotal
Mean26.64 ± 5.72926.36 ± 5.73226.54 ± 5.748
08

Study locations

149 sites
  • University of Alabama - Birmingham
    Birmingham, Alabama 35233, United States
  • GI Alliance - Arizona Digestive Health - Sun City
    Sun City, Arizona 85351, United States
  • David Geffen School of Medicine at UCLA
    Los Angeles, California 90095, United States
  • Facey Medical Foundation
    Mission Hills, California 91345, United States
  • Paradigm Clinical Research Centers, Inc
    Redding, California 96601, United States
  • University Of California Davis
    Sacramento, California 95817, United States
  • Midway Immunology and Research Center
    Ft. Pierce, Florida 34982, United States
  • Alliance Medical Research LLC
    Lighthouse PT, Florida 33064, United States
  • Phoenix Medical Research LLC
    Miami, Florida 33165, United States
  • San Marcus Research
    Miami Lakes, Florida 33014, United States
  • Gasteroenterology Group of Naples
    Naples, Florida 31402, United States
  • HeuerMD Research Inc
    Orlando, Florida 32819, United States
  • Pines Care Research Center Inc.
    Pembroke Pines, Florida 33026, United States
  • Bardmoor Gastroenterology
    Seminole, Florida 33777, United States
  • Professional Health Care of Pinellas
    St. Petersburg, Florida 33713, United States
  • Florida Medical Clinic P.A.
    Zephyrhills, Florida 33542, United States
  • Infectious Disease Specialists of Atlanta
    Decatur, Georgia 30333, United States
  • Grand Teton Research Group PLLC
    Idaho Falls, Idaho 83404, United States
  • GI Alliance - Illinois Gastro Group - Glenview
    Glenview, Illinois 60026, United States
  • Loyola University Medical Center
    Maywood, Illinois 60153, United States
  • UnityPoint Health Peoria/Proctor
    Peoria, Illinois 61603, United States
  • Southern Illinois University School of Medicine
    Springfield, Illinois 62702, United States
  • Carle Foundation Hospital
    Urbana, Illinois 61801, United States
  • The University of Kansas Medical Center
    Kansas City, Kansas 66160, United States
  • Ochsner Clinic Foundation
    New Orleans, Louisiana 70121, United States
  • University of Maryland School of Medicine
    Baltimore, Maryland 21201, United States
  • St. Vincent Hospital
    Worcester, Massachusetts 01608-1216, United States
  • Harper Hospital Department of Pharmacy Services
    Detroit, Michigan 48201-2020, United States
  • Detroit Receiving Hospital Department of Pharmacy Services
    Detroit, Michigan 48201, United States
  • Aa Mrc Llc
    Flint, Michigan 48504-4730, United States
  • William Beaumont Hospital
    Royal Oak, Michigan 48073-6712, United States
  • Revival Research Institute, LLC.
    Southfield, Michigan 48034, United States
  • Mercury Street Medical Group PLLC
    Butte, Montana 59701, United States
  • AB Clinical Trials
    Las Vegas, Nevada 89119, United States
  • New York Presbyterian Hospital Weill Cornell
    New York, New York 10021, United States
  • James J. Peters VAMC
    The Bronx, New York 10468, United States
  • ECU Adult Specialty Care
    Greenville, North Carolina 27834, United States
  • PMG Research of Winston-Salem
    Winston-Salem, North Carolina 27103, United States
  • St. Vincent Mercy Medical Center
    Toledo, Ohio 43608, United States
  • University of Pittsburgh Medical Center
    Pittsburgh, Pennsylvania 15213, United States
  • Monument Health Clinical Research
    Rapid City, South Dakota 57701, United States
  • Chattanooga Research and Medicine CHARM
    Chattanooga, Tennessee 37404-3230, United States
  • GI Alliance - Texas Digestive Disease Consultants - Arlington
    Arlington, Texas 76012, United States
  • GI Alliance - Texas Digestive Disease Consultants - Cedar Park
    Cedar Park, Texas 78613, United States
  • DM Clinical Research (Conroe Regional Hospital)
    Conroe, Texas 77304, United States
  • FMC Science
    Lampasas, Texas 76550, United States
  • GI Alliance - Texas Digestive Disease Consultants - San Marcos
    San Marcos, Texas 78666, United States
  • GI Alliance - Texas Digestive Disease Consultants - Webster
    Webster, Texas 77598, United States
  • Infectious Diseases Associates of Central VA
    Lynchburg, Virginia 24501, United States
  • Instituto Medico ALAS
    Salta, Argentina CP4400, Argentina
  • Centro Médico Talar
    El Talar, Buenos Aires 1608, Argentina
  • Instituto Medico Platense
    Buenos Aires, BI900AVG, Argentina
  • Hospital Italiano de Buenos Aires
    Buenos Aires, C1199ABB, Argentina
  • Hospital Ramos Mejía
    Buenos Aires, C1221ADC, Argentina
  • Hospital Privado Centro Medico Cordoba
    Córdoba, X5016KEH, Argentina
  • Westmead Hospital
    Westmead, New South Wales 2145, Australia
  • Sunshine Coast University Hospital
    Birtinya, Queensland 4575, Australia
  • Mater Misericordiae
    South Brisbane, Queensland 4101, Australia
  • Princess Alexandra Hospital
    Woolloongabba, Queensland 4102, Australia
  • Monash Medical Center
    Clayton, Victoria 3168, Australia
  • Fiona Stanley Hospital
    Murdoch, Western Australia 6150, Australia
  • Unidade de Pesquisa - NCS - Hospital Felício Rocho
    Belo Horizonte, Minas Gerais 30110-936, Brazil
  • Hospital Vera Cruz
    Belo Horizonte, Minas Gerais 30140-030, Brazil
  • Santa Casa De Misericordia De Belo Horizonte
    Belo Horizonte, Minas Gerais 30150221, Brazil
  • Santa Casa de Misericordia de Porto Alegre
    Porto Alegre, Rio Grande do Sul 90020090, Brazil
  • Hospital das Clinicas de Porto Alegre
    Porto Alegre, Rio Grande do Sul 90035-903, Brazil
  • Hospital Ernesto Dornelles
    Porto Alegre, Rio Grande do Sul 90160-092, Brazil
  • Fundacao Faculdade Regional de Medicina de Sao Jose do Rio Preto
    São José do Rio Preto, São Paulo 15090-000, Brazil
  • Hospital Alemao Oswaldo Cruz
    São Paulo, São Paulo 01327-001, Brazil
  • MHAT "Sv.Ivan Rilski-2003"OOD
    Dupnitsa, Kyustendil 2600, Bulgaria
  • DCC1-Sliven Ltd.
    Sliven, Sliven 8800, Bulgaria
  • DCC Alexandrovska
    Sofia, Sofia 1431, Bulgaria
  • "MHAT - Blagoevgrad, EOOD Department of Gastroenterology"
    Blagoevgrad, 2700, Bulgaria
  • Medical center - Izgrev
    Sofia, 1612, Bulgaria
  • Foothills Medical Centre, South Tower
    Calgary, Alberta T2N 2T9, Canada
  • Moncton Hospital/Horizon Health Network
    Moncton, New Brunswick E1C 6Z8, Canada
  • Lakeridge Health
    Oshawa, Ontario L1G 2B9, Canada
  • Centre Hospitalier de l'Universite de Montreal
    Montreal, Quebec H2X 1R9, Canada
  • Institut Universitaire de Cardiologie et de Pneumologie de Québec- ULaval
    Québec, Quebec G1V 4G5, Canada
  • Recherche Médicale St-Jérôme Inc
    Québec, Quebec J7Z 5T3, Canada
  • Centre integre universitaire de sante et de services sociaux de la Mauricie-et-du-Centre-du-Quebec
    Trois-Rivières, Quebec G8Z 3R9, Canada
  • General Hospital of Athens ''Evangelismos'
    Athens, 10676, Greece
  • General Hospital of Athens ''Alexandra''
    Athens, 115-28, Greece
  • "Pathophysiology Department Athens University Medical School"
    Athens, 11527, Greece
  • " ATTIKON University Hospital"
    Athens, 12462, Greece
  • "'Hygeia'' Hospital 2nd Department of Medicine and Infectious Diseases"
    Athens, 15121 Marousi, Greece
  • University Hospital of Heraklion
    Heraklion, 71110, Greece
  • University Hospital of Patras
    Pátrai, 265 04, Greece
  • ''Tzaneio'' General Hospital of Piraeus
    Piraeus, 185 -36, Greece
  • Békés Megyei Központi Kórház Pándy Kálmán Tagkórház, Infektológia-Hepatológia Osztály
    Gyula, Bekes County 5700, Hungary
  • Pest Megyei Flór Ferenc Kórház, V. Belgyógyászat
    Kistarcsa, Pest County 2143, Hungary
  • Javorszy Odon Hospital
    Vác, Vác 2600, Hungary
  • Dr. Kenessey Albert Kórház Rendelőintézet, Tüdőgyógyászati Aktív Osztály
    Balassagyarmat, 2660, Hungary
  • Békés Megyei Központi Kórház Dr. Réthy Pál Tagkórház IV. Belgyógyászat - 2. Gasztroenterológia
    Békéscsaba, 5600, Hungary
  • "Dél-Pesti Centrumkórház-OHII Szent László Kórház Infektológiai Osztály "
    Budapest, H-1097, Hungary
  • Országos Korányi Pulmonológiai Intézet, Központi Intenzív osztály
    Budapest, H-1122, Hungary
  • CRU Hungary Kft BAZ Megyei Kórház és Egyetemi Oktatókórház, Szent Ferenc Tagkórház
    Miskolc, 3529, Hungary
  • "Pécsi Tudományegyetem I. sz. Belgyógyászat i Klinika, Infektológiai tanszék"
    Pécs, H-7623, Hungary
  • Pécsi Tudományegyetem Klinikai Központi Gyógyszertár
    Pécs, H-7624, Hungary
  • Csongrad County Dr. Bugyi Istvan Hospital, Dept. Of Internal Medicine
    Szentes, H-6600, Hungary

Showing the first 100 of 149 sites across 14 countries. Choose a country and city above to see the rest.

09

References and documents

Publications

  • Okhuysen PC, Ramesh MS, Louie T, Kiknadze N, Torre-Cisneros J, de Oliveira CM, Van Steenkiste C, Stychneuskaya A, Garey KW, Garcia-Diaz J, Li J, Duperchy E, Chang BY, Sukbuntherng J, Montoya JG, Styles L, Clow F, James D, Dubberke ER, Wilcox M. A Randomized, Double-Blind, Phase 3 Safety and Efficacy Study of Ridinilazole Versus Vancomycin for Treatment of Clostridioides difficile Infection: Clinical Outcomes With Microbiome and Metabolome Correlates of Response. Clin Infect Dis. 2024 Jun 14;78(6):1462-1472. doi: 10.1093/cid/ciad792. PubMed 38305378 ↗
  • Carlson TJ, Endres BT, Basseres E, Gonzales-Luna AJ, Garey KW. Ridinilazole for the treatment of Clostridioides difficile infection. Expert Opin Investig Drugs. 2019 Apr;28(4):303-310. doi: 10.1080/13543784.2019.1582640. Epub 2019 Feb 26. PubMed 30767587 ↗

Study documents

PDFs hosted by the registry, ClinicalTrials.gov.

Individual participant data

Plan to share: No

10

Updates

1 registry update since Sep 25, 2026
Results
Posted results revised
revised Oct 9, 2026
Sites
35 sites added, 35 sites removed
Show 35 added (7 Romania, 5 Brazil, 4 United States, 4 Poland, 3 Canada, 3 Hungary, 2 Argentina, 2 Bulgaria, 2 Spain, 1 Greece, 1 New Zealand, 1 South Korea)
  • Midway Immunology and Research Center · Ft. Pierce, United States
  • Alliance Medical Research LLC · Lighthouse PT, United States
  • Professional Health Care of Pinellas · St. Petersburg, United States
  • James J. Peters VAMC · The Bronx, United States
  • Instituto Medico ALAS · Salta, Argentina
  • Hospital Privado Centro Medico Cordoba · Córdoba, Argentina
  • Santa Casa de Misericordia de Porto Alegre · Porto Alegre, Brazil
  • Hospital das Clinicas de Porto Alegre · Porto Alegre, Brazil
  • Hospital Ernesto Dornelles · Porto Alegre, Brazil
  • Fundacao Faculdade Regional de Medicina de Sao Jose do Rio Preto · São José do Rio Preto, Brazil
  • Hospital Alemao Oswaldo Cruz · São Paulo, Brazil
  • DCC1-Sliven Ltd. · Sliven, Bulgaria
  • DCC Alexandrovska · Sofia, Bulgaria
  • Centre Hospitalier de l'Universite de Montreal · Montreal, Canada
  • Institut Universitaire de Cardiologie et de Pneumologie de Québec- ULaval · Québec, Canada
  • Recherche Médicale St-Jérôme Inc · Québec, Canada
  • University Hospital of Patras · Pátrai, Greece
  • Békés Megyei Központi Kórház Pándy Kálmán Tagkórház, Infektológia-Hepatológia Osztály · Gyula, Hungary
  • Pest Megyei Flór Ferenc Kórház, V. Belgyógyászat · Kistarcsa, Hungary
  • Javorszy Odon Hospital · Vác, Hungary
  • Waikato District Health Board Waikato Hospital · Hamilton, New Zealand
  • Gabinet Lekarski Bartosz Korczowski · Rzeszów, Poland
  • Korczowski Bartosz Gabinet · Rzeszów, Poland
  • Centralny Szpital Kliniczny MSWiA Klinika Chorób Wewnętrznych i Gastroenterologii · Warsaw, Poland
  • Klinika Chorób Wewnętrznych i Gastroenterologii z Pododdziałem Leczenia Nieswoistych Chorób Zapalnych Jelit Centralny Szpital Kliniczny MSWiA · Warsaw, Poland
  • SUUMC-Boli infectioase · Bucharest, Romania
  • Clinical Hospital of Infectious and Tropical Diseases "Dr. Victor Babes" · Bucharest, Romania
  • S.C. Sana Monitoring Srl · Bucharest, Romania
  • Spitalul Clinic de Boli Infectioase si Tropicale · Bucharest, Romania
  • Spitalul Clinic de Boli Infectioase Constanta · Constanța, Romania
  • …and 5 more on the registry record
Show 35 removed
  • Midway Immunology and Research Center · Fort Pierce, United States
  • Alliance Medical Research LLC · Lighthouse Point, United States
  • Professional Health Care of Pinellas · Saint Petersburg, United States
  • James J. Peters VAMC · Bronx, United States
  • Hospital Privado Centro Medico Cordoba · Cordoba, Argentina
  • Instituto Medico ALAS · Salta, Argentina
  • Santa Casa de Misericordia de Porto Alegre · Porto Alegre, Brazil
  • Hospital das Clinicas de Porto Alegre · Porto Alegre, Brazil
  • Hospital Ernesto Dornelles · Porto Alegre, Brazil
  • Fundacao Faculdade Regional de Medicina de Sao Jose do Rio Preto · Sao Jose do Rio Preto, Brazil
  • Hospital Alemao Oswaldo Cruz · Sao Paulo, Brazil
  • DCC1-Sliven Ltd. · Sliven, Bulgaria
  • DCC Alexandrovska · Sofia, Bulgaria
  • Centre Hospitalier de l'Universite de Montreal · Montréal, Canada
  • Institut Universitaire de Cardiologie et de Pneumologie de Québec- ULaval · Quebec, Canada
  • Recherche Médicale St-Jérôme Inc · Quebec, Canada
  • University Hospital of Patras · Patras, Greece
  • Békés Megyei Központi Kórház Pándy Kálmán Tagkórház, Infektológia-Hepatológia Osztály · Gyula, Hungary
  • Pest Megyei Flór Ferenc Kórház, V. Belgyógyászat · Kistarcsa, Hungary
  • Javorszy Odon Hospital · Vác, Hungary
  • Hanyang University Guri Hospital · Guri-Si, Korea, Republic of
  • Waikato District Health Board Waikato Hospital · Hamilton, New Zealand
  • Gabinet Lekarski Bartosz Korczowski · Rzeszów, Poland
  • Korczowski Bartosz Gabinet · Rzeszow, Poland
  • Centralny Szpital Kliniczny MSWiA Klinika Chorób Wewnętrznych i Gastroenterologii · Warszawa, Poland
  • Klinika Chorób Wewnętrznych i Gastroenterologii z Pododdziałem Leczenia Nieswoistych Chorób Zapalnych Jelit Centralny Szpital Kliniczny MSWiA · Warszawa, Poland
  • SUUMC-Boli infectioase · Bucuresti, Romania
  • Clinical Hospital of Infectious and Tropical Diseases "Dr. Victor Babes" · Bucuresti, Romania
  • S.C. Sana Monitoring Srl · Bucuresti, Romania
  • Spitalul Clinic de Boli Infectioase si Tropicale · Bucuresti, Romania
  • …and 5 more on the registry record
Oct 9, 2026
Publications
1 publication citing this study linked from PubMed, e.g. PubMed 38305378 ↗
Oct 9, 2026
Show all 1 update
  1. Oct 9, 2026
    Posted results revised
    Publications 1 publication citing this study linked from PubMed, e.g. PubMed 38305378 ↗
    35 sites added, 35 sites removed
    Show 35 added (7 Romania, 5 Brazil, 4 United States, 4 Poland, 3 Canada, 3 Hungary, 2 Argentina, 2 Bulgaria, 2 Spain, 1 Greece, 1 New Zealand, 1 South Korea)
    • Midway Immunology and Research Center · Ft. Pierce, United States
    • Alliance Medical Research LLC · Lighthouse PT, United States
    • Professional Health Care of Pinellas · St. Petersburg, United States
    • James J. Peters VAMC · The Bronx, United States
    • Instituto Medico ALAS · Salta, Argentina
    • Hospital Privado Centro Medico Cordoba · Córdoba, Argentina
    • Santa Casa de Misericordia de Porto Alegre · Porto Alegre, Brazil
    • Hospital das Clinicas de Porto Alegre · Porto Alegre, Brazil
    • Hospital Ernesto Dornelles · Porto Alegre, Brazil
    • Fundacao Faculdade Regional de Medicina de Sao Jose do Rio Preto · São José do Rio Preto, Brazil
    • Hospital Alemao Oswaldo Cruz · São Paulo, Brazil
    • DCC1-Sliven Ltd. · Sliven, Bulgaria
    • DCC Alexandrovska · Sofia, Bulgaria
    • Centre Hospitalier de l'Universite de Montreal · Montreal, Canada
    • Institut Universitaire de Cardiologie et de Pneumologie de Québec- ULaval · Québec, Canada
    • Recherche Médicale St-Jérôme Inc · Québec, Canada
    • University Hospital of Patras · Pátrai, Greece
    • Békés Megyei Központi Kórház Pándy Kálmán Tagkórház, Infektológia-Hepatológia Osztály · Gyula, Hungary
    • Pest Megyei Flór Ferenc Kórház, V. Belgyógyászat · Kistarcsa, Hungary
    • Javorszy Odon Hospital · Vác, Hungary
    • Waikato District Health Board Waikato Hospital · Hamilton, New Zealand
    • Gabinet Lekarski Bartosz Korczowski · Rzeszów, Poland
    • Korczowski Bartosz Gabinet · Rzeszów, Poland
    • Centralny Szpital Kliniczny MSWiA Klinika Chorób Wewnętrznych i Gastroenterologii · Warsaw, Poland
    • Klinika Chorób Wewnętrznych i Gastroenterologii z Pododdziałem Leczenia Nieswoistych Chorób Zapalnych Jelit Centralny Szpital Kliniczny MSWiA · Warsaw, Poland
    • SUUMC-Boli infectioase · Bucharest, Romania
    • Clinical Hospital of Infectious and Tropical Diseases "Dr. Victor Babes" · Bucharest, Romania
    • S.C. Sana Monitoring Srl · Bucharest, Romania
    • Spitalul Clinic de Boli Infectioase si Tropicale · Bucharest, Romania
    • Spitalul Clinic de Boli Infectioase Constanta · Constanța, Romania
    • …and 5 more on the registry record
    Show 35 removed
    • Midway Immunology and Research Center · Fort Pierce, United States
    • Alliance Medical Research LLC · Lighthouse Point, United States
    • Professional Health Care of Pinellas · Saint Petersburg, United States
    • James J. Peters VAMC · Bronx, United States
    • Hospital Privado Centro Medico Cordoba · Cordoba, Argentina
    • Instituto Medico ALAS · Salta, Argentina
    • Santa Casa de Misericordia de Porto Alegre · Porto Alegre, Brazil
    • Hospital das Clinicas de Porto Alegre · Porto Alegre, Brazil
    • Hospital Ernesto Dornelles · Porto Alegre, Brazil
    • Fundacao Faculdade Regional de Medicina de Sao Jose do Rio Preto · Sao Jose do Rio Preto, Brazil
    • Hospital Alemao Oswaldo Cruz · Sao Paulo, Brazil
    • DCC1-Sliven Ltd. · Sliven, Bulgaria
    • DCC Alexandrovska · Sofia, Bulgaria
    • Centre Hospitalier de l'Universite de Montreal · Montréal, Canada
    • Institut Universitaire de Cardiologie et de Pneumologie de Québec- ULaval · Quebec, Canada
    • Recherche Médicale St-Jérôme Inc · Quebec, Canada
    • University Hospital of Patras · Patras, Greece
    • Békés Megyei Központi Kórház Pándy Kálmán Tagkórház, Infektológia-Hepatológia Osztály · Gyula, Hungary
    • Pest Megyei Flór Ferenc Kórház, V. Belgyógyászat · Kistarcsa, Hungary
    • Javorszy Odon Hospital · Vác, Hungary
    • Hanyang University Guri Hospital · Guri-Si, Korea, Republic of
    • Waikato District Health Board Waikato Hospital · Hamilton, New Zealand
    • Gabinet Lekarski Bartosz Korczowski · Rzeszów, Poland
    • Korczowski Bartosz Gabinet · Rzeszow, Poland
    • Centralny Szpital Kliniczny MSWiA Klinika Chorób Wewnętrznych i Gastroenterologii · Warszawa, Poland
    • Klinika Chorób Wewnętrznych i Gastroenterologii z Pododdziałem Leczenia Nieswoistych Chorób Zapalnych Jelit Centralny Szpital Kliniczny MSWiA · Warszawa, Poland
    • SUUMC-Boli infectioase · Bucuresti, Romania
    • Clinical Hospital of Infectious and Tropical Diseases "Dr. Victor Babes" · Bucuresti, Romania
    • S.C. Sana Monitoring Srl · Bucuresti, Romania
    • Spitalul Clinic de Boli Infectioase si Tropicale · Bucuresti, Romania
    • …and 5 more on the registry record
    + 3 other changes: index terms, identifiers and verification date

From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗

11

Registry details

Key details

Study ID
NCT03595553
Lead sponsor
Summit Therapeutics
Responsible party
Sponsor
First posted
Jul 23, 2018
Start date
Jan 28, 2019
Primary completion
Nov 17, 2021
Completion
Nov 17, 2021
Results posted
Mar 3, 2023
Last update
Oct 9, 2026

Study contacts

Lori Styles, MD
study director · Summit Therapeutics

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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