The main purpose of this study is to determine if Oxalobacter formigenes is effective at
lowering urinary oxalate levels in patients with primary hyperoxaluria.
1. The subject (or legally acceptable representative) must give written informed consent
(and assent for subjects ≥ 12 years or country specific age as appropriate). For
subjects less than 18 years of age, parent or guardian will provide informed consent
and the subject will provide witnessed verbal assent
2. Male or female subjects ≥ 5 years of age
3. Urinary oxalate excretion of > 1.0 mmol/1.73m2/day at Baseline
4. Documentation of diagnosis of PH I or PH II by any one of the following:
1. Liver biopsy confirmation of deficient liver specific peroxisomal
alanine-glyoxylate aminotransferase, (AGT) or mislocalization of AGT from
peroxisomes to mitochondria (PH I) or deficient glyoxylate
reductase/hydroxypyruvate reductase (GR/HPR) activity (PH II)
2. Homozygosity or compound heterozygosity for a known mutation in the causative
genes for PH I and PH II
3. Increased glycolate excretion for PH I or increased L-glycerate excretion for PH
5. Subjects receiving pyridoxine must be receiving a stable dose for at least 3 months
prior to entry in to the study and must remain on the stable dose during the study.
Other (non-pyridoxine naïve) subjects (e.g. Pyridoxine non-responder: <30% reduction
of the urine oxalate levels) not receiving pyridoxine at study entry must be willing
to refrain from initiating pyridoxine during study participation. Note: There will
be no pyridoxine-naïve subjects enrolled in the study.
6. Renal function defined as an estimated GFR ≥ 50 ml/min normalized to 1.73m2 body
1. Pregnant, lactating, or actively menstruating women and women of child-bearing
potential who are not using adequate contraceptive precautions. Sexually active
females, unless surgically sterile or at least 2 years post-menopausal, must be using
a highly effective contraception (including oral, transdermal, injectable, or
implanted contraceptives, IUD, abstinence, use of a condom by the sexual partner, or
sterile sexual partner) for 30 days prior to the first dose of OxabactTM and must
agree to continue using such precautions during the clinical study.
Note: A highly effective method of birth control is defined as one that results in a
low failure rate (i.e. less than 1% per year) when used consistently and correctly,
such as implants, injectables, combined oral contraceptives, some intrauterine
contraceptive devices (IUDs), sexual abstinence, or a vasectomised partner.
2. Positive serum pregnancy test.
3. Participation in any study of an investigational product, biologic, device, or other
agent within 30 days prior to randomization or not willing to forego other forms of
investigational treatment during this study.
4. Subjects on hemodialysis or peritoneal dialysis.
5. Subjects who have undergone transplantation (solid organ or bone marrow).
6. Chronic gastrointestinal disease associated with enteric hyperoxaluria, e.g. history
of inflammatory bowel disease, colostomy. Note: For clarity, existence of Secondary
Hyperoxaluria (e.g. with cystic fibrosis, chronic inflammatory bowel diseases, short
bowel syndrome and/or deficiency of intestinal oxalate-degrading bacteria is included
(as an exclusion criteria).
7. Current systemic (oral, IM, IV) antibiotic use or received systemic antibiotics
within 14 days of study enrolment.
8. History of chronic, recurrent infections requiring >2 courses of antibiotics in the
past 6 months.
9. History of malignancy except for basal or squamous cell skin cancer that has been
10. Unable to collect 24-hour urine samples or follow other study procedures.
11. Subjects who cannot swallow a size 2 capsule.
12. 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
13. Subjects who require immune suppressive therapy (including prednisone of > 10mg daily
for more than 2 weeks).
14. Subjects from correctional facilities or asylums.
15. Subjects who are mentally handicapped.