Multiple ascending dose KLH antigen challenge study of EDP1815

Participants are eligible to be included in the study only if all of the
following criteria apply:
1. Capable of giving signed informed consent which includes compliance
with the requirements and restrictions listed in the informed consent form
(ICF) and in this protocol. Obtained prior to any screening procedures and
in accordance with national, local, institutional guidelines.
2. Age ≥ 18 years to 60 years, inclusive.
3. Participant has a body mass index of ≥ 18 kg/m2 to ≤ 35 kg/m2 at
Screening.
4. Contraception:
a. Male participants:
• A male participant must agree to use contraception during their
participation in this study and for a period of 90
days after the last dose and refrain from donating sperm during this
period.
b. Female participants:
• A female participant is eligible to participate if she is not pregnant, not
breastfeeding, and at least 1 of the
following conditions applies:
i. Not a woman of child-bearing potential (WOCBP)
OR
ii. A WOCBP who agrees to follow the contraceptive guidance during their
participation in this study and for at least 1 complete menstrual cycle (≥30
days) after last dose.
5. CRP ≤ 10 mg/L and faecal calprotectin ≤ 150 mcg/g faeces
6. The participant has clinical laboratory evaluations (including clinical
chemistry, haematology, and complete urinalysis) within the reference
range for the testing laboratory, unless the results are deemed not to be
clinically significant by the investigator (1 repeat test is permitted).
7. Participants who are overtly healthy as determined by medical
evaluation including medical history, physical examination, laboratory
tests, and cardiac monitoring at Screening and on Day 1.
8. Subject needs to have sufficient space in a refrigerator to store the IMP
during the ambulant dosing phase.
9. Participant has the ability to communicate well with the Investigator in
the Dutch language and willing to comply with the study restrictions.

1. Female participant who is pregnant, or plans to become pregnant
during the study, or breastfeeding, or sexually active with child-bearing
potential who is not using a medically accepted birth control method.
2. Participant has received live attenuated vaccination within 6 weeks
prior to Screening or intends to have vaccinations during the course of the
study.
3. Participant has received any investigational drug or experimental
procedure within 90 days or 5 half-lives, whichever is longer, prior to study
intervention administration.
4. Participant was enrolled in an investigational drug or device study
within 3 months prior to first dosing.
5. Participant requires treatment with an anti-inflammatory drug during
the study period. Paracetamol will be permitted for use as an antipyretic
and/or analgesic (maximum of 4 grams/day in any 24-hour period).
6. Participant has an active infection (e.g. sepsis, pneumonia, abscess) or
recurrent infection, or has had an infection requiring antibiotic treatment
within 6 weeks prior to Investigational Medicinal Product (IMP)
administration.
7. Participant is diagnosed with tuberculosis (TB, as per positive skin test
(Mantoux) or IFN-γ release assay), or history of TB, or latent TB, or recent
contact with TB (patient); having travelled to countries where TB is
endemic within eight weeks of planned drug administration or planning to
travel to countries where TB is endemic from the
moment of drug administration until three months after the end of the
study.
8. Patient requires prophylactic antibiotics for any reason
9. Participant has renal or liver impairment, defined as:
a. For women, serum creatinine level ≥ 125 μmol/L; for men, ≥ 135 μmol/L
b. An estimated creatinine clearance (MDRD formula) <60 mL/min
c. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≥
1.5 x upper limit of normal (ULN), or
d. Alkaline phosphatase (ALP) and/or bilirubin > 2.5 x ULN
10. Participant has active neoplastic disease or history of neoplastic
disease within 5 years of Screening (except for basal or squamous cell
carcinoma of the skin or carcinoma in situ that has been definitively
treated with standard of care).
11. Impaired cardiac function or clinically significant cardiac diseases,
including any of the following:
a. Unstable angina or acute myocardial infarction ≤ 3 months prior to
Screening;
b. Clinically significant heart disease (e.g. symptomatic congestive heart
failure [e.g. >New York Heart Association
[NYHA] Class 2]; uncontrolled arrhythmia, or hypertension; history of
labile hypertension or poor compliance with an antihypertensive regimen.
12. Participant with a positive screening result for hepatitis B surface
antigen, anti-hepatitis B core, hepatitis C, or HIV.
13. Participants with gastrointestinal tract disease (e.g. short bowel
syndrome, diarrhoea predominant irritable bowel syndrome [IBS], celiac
disease) that could interfere with the subject’s safety or
pharmacodynamic effect of the monoclonal microbial.
14. Serious psychiatric or medical conditions that, in the opinion of the
investigator, could interfere with treatment, compliance, or the ability to
give consent.
15. The participant has a history of hypersensitivity or allergies to
Prevotella (or Prevotella containing probiotics) including any associated
excipients, or has a history of hypersensitivity or allergies to placebo
capsule/powder (magnesium stearate and cellulose) or to the hard
capsule shells (hydroxyl propyl methyl cellulose and titanium
dioxide), or has a known allergy against Alhydrogel®.
16. Participant has a history of Schistosomiasis (infection with Schistosoma
parasite).
17. The participant has taken any over-the-counter (OTC) medication (with
the exception of paracetamol and anti-histamines) within 14 days prior to
Baseline (Day -1) or any prescription medications or nutraceuticals (e.g.
supplements including high doses of probiotics and prebiotics, as usually
found in capsules/tablets/powders) within 28 days prior to Baseline (Day -
1) or anticipates an inability to abstain from these products for the
duration of the study period. Note that probiotic and prebiotic foods e.g.
yoghurts that contain low doses are allowed.
18. The participant uses probiotic capsules within 2 weeks prior to
screening.
19. The participant has a significant history of drug abuse or regular use of
illicit drugs or a history of alcohol abuse within 1 year prior to Screening.
20. The participant uses more than 10 cigarettes per day and/or is unable
to refrain from cigarettes or tobacco use or other nicotine-containing
products (e.g., patches) during 4 consecutive days.
21. The participant intends to donate sperm during the course of this
study and for a period of 90 days after the last dose.
22. The participant has donated more than 400 mL of blood or blood
products within 90 days prior to Baseline (Day -1) or plans to donate blood
during the study.
23. The participant has a diastolic blood pressure ≤50 or ≥90 mm Hg, or a
systolic blood pressure ≤105 or ≥140 mm Hg at Screening or Baseline (Day
-1) unless deemed to be not clinically significant by the investigator.
24. The participant has had an acute, clinically significant illness or major
surgery within 30 days prior to screening.