ClinicalTrials.gg
CompletedNCT02012985Updated Oct 16, 2015

Study to Evaluate the Efficacy and Safety of Oxabact (OC5) in Patients With Primary Hyperoxaluria

A Phase 1/2 interventional study of Oxabact OC5 capsules and Placebo capsules in Primary Hyperoxaluria, sponsored by OxThera. Completed at 8 sites in 3 countries. Open to participants aged 2 Years and older. Per ClinicalTrials.gov, last updated 2015-10-16.

Sponsored by OxThera · Phase 1/2, Interventional, and Treatment

Phase
Phase 1/2
Study type
Interventional
Enrollment
28
Allocation
Randomized
Ages
2 Years and older
Sex
All
01

Study summary

The purpose of this study is to determine if Oxalobacter formigenes is effective at lowering urinary oxalate levels in patients with primary hyperoxaluria.

02

Conditions studied

  • Primary Hyperoxaluria

Keywords

  • hyperoxaluria
  • oxalate
  • PH
03

In context

Hyperoxaluria, Primary

42 studies on the registry are indexed under Hyperoxaluria, Primary; 11 are open to participants now.

This study's enrollment of 28 is above the median of 24 across 26 interventional studies indexed under Hyperoxaluria, Primary.

Browse Hyperoxaluria, Primary studies →

Lead sponsor

OxThera is the lead sponsor of 6 studies on the registry; none are open to participants now.

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

04

Who can participate

Ages eligible
2 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

  • Signed (as applicable for the age of the subject).
  • Male or female subjects ≥ 2 years of age (Germany \& France) / Male or female subjects ≥ 5 years of age (United Kingdom)
  • A diagnosis of PH type I, II or III (as determined by standard diagnostic methods).
  • A mean urinary oxalate excretion of > 1.0 mmol/24h/1.73m2, based on at least three eligible urine collections performed during baseline (weeks 1-4).
  • Renal function defined as an estimated ≥ 40 ml/min normalised to 1.73m2 body surface area, or a of ≥ 40 ml/min normalised to 1.73m2 body surface area.
  • Subjects receiving vitamin B6 must be receiving a stable dose for at least 3 months prior to screening and must not change the dose during the study. Subjects not receiving vitamin B6 at study entry must be willing to refrain from initiating pyridoxine during study participation.

Exclusion criteria

Exclusion Criteria:

  • Inability to collect complete 24-hour urine samples. Each urine collection will be evaluated for completeness based on urine qualitative criteria.
  • Inability to swallow size 4 capsules twice daily for 8 to 10 weeks.
  • Subjects that have undergone transplantation (solid organ or bone marrow).
  • The existence of secondary hyperoxaluria, e.g. hyperoxaluria due to bariatric surgery or chronic gastrointestinal diseases such as cystic fibrosis, chronic inflammatory bowel disease and short-bowel syndrome.
  • Use of antibiotics to which O. formigenes is sensitive, including chronic use, a history of more than two courses of antibiotic use during the past 6 months, current antibiotic use, or antibiotics use within 14 days of initiating study medication.
  • Subjects who require immune suppressive therapy.
  • Current treatment with ascorbic acid preparation.
  • Pregnancy.
  • Women of who are not using adequate precautions such as oral, transdermal, injectable, or implanted contraceptives, IUD, complete abstinence, use of a condom by the sexual partner, or sterile sexual partner.
  • Presence of a medical condition that the Principal Investigator considers likely to make the subject susceptible to adverse effect of study treatment or unable to follow study procedures.
  • Participation in any study of an product, biologic, device, or other agent within 30 days prior to screening or not willing to forego other forms of investigational treatment during this study.
Terms in these criteria, in plain language(6)

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.

GFR and eGFR (kidney filtering)

GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².

Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.

Creatinine clearance (CrCl)

How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.

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.

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.

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.

05

Study design

Phase
Phase 1 / Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
28 participants (actual)

Study arms

  • Experimental
    Oxabact OC5 capsules

    The active study drug consists of Oxalobacter formigenes OC5 in enteric-coated size-4 capsules. The dose (not less than (NLT) 1E+09 colony forming units (CFU)) will be administrated orally with breakfast and dinner as one capsule two times per day for 8 to 10 weeks.

    Biological: Oxabact OC5 capsules

  • Placebo comparator
    Placebo capsules

    The placebo study drug consists of microcrystalline cellulose in enteric-coated size-4 capsules. It has been manufactured to mimic the OC5 capsule. The dose will be administrated orally with breakfast and dinner as one capsule two times per day for 8 to 10 weeks.

    Drug: Placebo capsules

Interventions

  • The dose will be not less than (NLT) 1E+09 colony forming units (CFU) twice daily for 8 to 10 weeks. The dose (an enteric-coated size 4 capsule) will be administered orally with breakfast and dinner.

    Also known as: Oxalobacter formigenes

  • DrugPlacebo capsules

    An enteric-coated placebo capsule manufactured to mimic the OC5 capsule. The capsule will be administered orally with breakfast and dinner twice daily for 8 to 10 weeks.

06

What researchers measure

Primary outcomes

  1. Change in urinary oxalate levels from Baseline to week 8 of treatment.

    Time frame: 8 weeks of active treatment (i.e. between Weeks 7 and 14 of the study)

Secondary outcomes

  1. Change in urinary oxalate levels from Baseline to week 8 of treatment in subsets of subjects

    Change in urinary oxalate levels from Baseline to week 8 of treatment in subsets of subjects defined by: * baseline urinary oxalate level, above and below 1.5 mmol/24h/1.73m2 * concomitant vitamin B6 therapy and no vitamin B6 therapy * eGFR of ≥90 mL/min/1.73m2 (normal renal function) and \< 90 mL/min/1.73m2 (mild to moderate reduction in renal function) * age below 18 and age 18 or above

    Time frame: 8 weeks of active treatment (i.e. between Weeks 7 and 14 of the study)

  2. Number of subjects who reach urinary oxalate levels below 0.5, 0.7 and 1.0 mmol/24h/1.73m2 respectively from Baseline to week 8 of treatment.

    Time frame: 8 weeks of active treatment (i.e. between Weeks 7 and 14 of the study)

  3. Change in plasma oxalate levels from Baseline to week 8 of treatment.

    Time frame: 8 weeks of active treatment (i.e. between Weeks 7 and 14 of the study)

  4. Change in urinary oxalate levels from Baseline to week 4 of treatment.

    Time frame: 8 weeks of active treatment (i.e. between Weeks 7 and 10 of the study)

  5. Correlation between change in plasma oxalate levels and change in urinary oxalate levels, from Baseline to week 8 of treatment.

    Time frame: 8 weeks of active treatment (i.e. between Weeks 7 and 14 of the study)

  6. Change in number of O. formigenes in faeces from Baseline to week 8 of treatment.

    Time frame: 8 weeks of active treatment (i.e. between Weeks 7 and 14 of the study)

  7. Adverse events

    Time frame: 8 weeks of active treatment (i.e. between Weeks 7 and 14 of the study)

  8. Haematology

    Blood samples taken for hematology at weeks 0, 5, 10 and 14. Complete blood count with differential and platelet count evaluated.

    Time frame: 14 weeks (Throughout the study)

  9. Clinical Chemistry

    Blood samples taken for clinical chemistry at weeks 0, 5, 10 and 14. Blood Urea Nitrogen, creatinine, electrolytes (Na+, K+, Mg++, Ca++, HCO3+, Cl), glucose, pH, albumin, alkaline phosphatase, ALT, AST, total bilirubin and total protein evaluated.

    Time frame: 14 weeks (Throughout the study)

  10. Urinalysis

    Urine samples will be taken at weeks 0, 5, 10 and 14 of the study. Protein, glucose and pH evaluated.

    Time frame: 14 weeks (Throughout the study)

07

Study locations

8 sites
  • Hôpital Robert-Debré, Néphrologie Pédiatrique
    Paris, Cedex 19 75945, France
  • Hôpital des Enfants, Centre de référence maladies rénales rares du Sud-Ouest (SORARE), CHU de Bordeaux
    Bordeaux, 33076, France
  • Hôpital Femme Mère Enfant, Lyon - Paediatric Dept
    Lyon, 69677 Bron, France
  • Hôpital Necker-Enfants Malades,Centre de référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA)
    Paris, 75015, France
  • Universitätsklinikum Bonn, Dept of Paediatric Nephrology
    Bonn, DE-53113, Germany
  • Birmingham Children's Hospital NHS Foundation Trust - Dept of Nephrology
    Birmingham, B4 6NH, United Kingdom
  • Royal Free Hospital -UCL Centre for Nephrology
    London, NW3 2QG, United Kingdom
  • Great Ormond Street Hospital for Children NHS Trust
    London, WCIN 3JH, United Kingdom
08

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Oct 16, 2015, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT02012985
Lead sponsor
OxThera
Collaborators
FP7-SME-2013 Research for the benefit of SMEs program
Responsible party
Sponsor
First posted
Dec 17, 2013
Start date
Dec 2013
Primary completion
Jan 2015
Completion
Jan 2015
Last update
Oct 16, 2015

Study contacts

Bernd Hoppe, MD PhD
principal investigator · Universitätsklinikum Bonn, Dept of Paediatric Nephrology

Oversight

Data monitoring committee
No
View the source record on ClinicalTrials.gov ↗

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Studies of the drug tested here: Oxalobacter formigenes

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