A Phase 1 interventional study of VENBETA6890 and Placebo in Diarrhea Infectious, sponsored by Mark Klempner. Completed at 1 site in United States. Open to participants aged 18 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-07-22.
Sponsored by Mark Klempner · Phase 1, Interventional, and Prevention
This is a phase 1, randomized, placebo-controlled, blinded study in up to 36 healthy adults, aged 18-45 years, challenged with Enterotoxigenic Escherichia coli, evaluating the safety, tolerability and anti-diarrheal activity of VENBETA6890, an orally administered, human monoclonal IgA.
Part A will consist of 1 sentinel dosing group of 2 subjects randomized 1:1 to receive VENBETA6890 or placebo and will evaluate VENBETA6890 at dose levels of 15 mg/kg. On Day 1, subjects will receive 15 mg/kg in the morning and a second dose of 15 mg/kg 8 - 12 h later in the outpatient clinic. On Day 2, they will receive a third dose of 15 mg/kg at approximately 8 - 12 h after the last dose on Day 1. The occurrence of local and systemic reactogenicity (solicited AEs) over the subsequent 7-days post-dosing will be collected; non-solicited non-serious AEs will be collected through 28-days post-dosing and serious adverse events (SAEs) will be collected through 2 months. An independent Safety Monitoring Committee (SMC) will review the cumulative 7-day safety data for the sentinel group and must approve for the study to proceed to Part B.
Part B will consist of a single inpatient cohort of up to 34 subjects who will be randomized 1:1 to receive VENBETA6890 15 mg/kg, or placebo on Day -1 at approximately 12 h pre-challenge, Day 1 at approximately 1 h pre-challenge, and Day 1 at approximately 12 h post-challenge. All subjects will be challenged with wild-type ETEC strain H10407 and will be closely monitored on the inpatient unit for ETEC diarrheal illness. Subjects will receive the 3-day course of antibiotic therapy starting on Day 6 or earlier dependent on symptoms. Discharge from the inpatient unit is contingent upon the absence of ETEC diarrheal illness, including no diarrhea and no fever, plus two sequential negative stool cultures for ETEC separated by at least 12 hours.
An SMC will review the cumulative safety data after data collected during the Day 29 visit of the inpatient challenge cohort has been compiled.
44 studies on the registry are indexed under Dysentery; 6 are open to participants now.
This study's enrollment of 36 is below the median of 163 across 38 interventional studies indexed under Dysentery.
Browse Dysentery studies →This is the only study on the registry with Mark Klempner as lead sponsor.
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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.
1. Male or female ages 18-45 years, inclusive at screening 2. Body weight 50 to 105 kg, inclusive at screening 3. Provide written before initiation of any study procedures. 4. Willing and able to complete all study requirements, restrictions, confinement to the Research Isolation ward, visits and procedures 5. Completion of a training session and demonstration of comprehension of the protocol procedures and knowledge of ETEC-associated illness by passing a written examination (passing grade is at least 70%).
6. Healthy as judged by the Principal Investigator (PI) and determined by medical history, physical examination, medication history, and laboratory assessments.
7. At Screening: Normal to Grade 1 values14 for the following laboratory determinations:
Male subjects with female sexual partner(s) of must fall into one of the following categories to qualify for enrollment:
Must agree to use a physical barrier method of contraception (e.g., a male condom) in addition to their partner's use (if partner is a WOCBP) of a birth control method from the time of Screening until 90 days after the last dose of study drug. The following methods of contraception are acceptable for use by female partners (if WOCBP) of male subjects:
Contraceptive sponge with condom Male subjects must agree not to donate sperm from the time of Check-in through 90 days after the final dose of study drug 9. Agrees to avoid live-culture yogurt and other probiotics for at least 14 days prior to the first dose of VENBETA6890 and during the study.
10. Agrees not to participate in another clinical trial during the study period.
Exclusion Criteria:
1. Positive pregnancy test at Screening or within 24 h prior to VENBETA6890 or placebo dosing 2. Breastfeeding 3. Poor venous access, as defined by inability to obtain venous blood, for screening labs, after 3 venipuncture attempts 4. Abnormal vital signs, defined as:
>450 msec for males or >460 msec for females 6. IgA deficiency 7. Evidence of current or past infection with testing for (HIV), virus (HCV) antibody, or triple screening panel (Hepatitis B surface antigen, Hepatitis B surface antibody, Hepatitis B total core antibody) with confirmatory testing as indicated.
8. Having received prior vaccines for or have had prior infection with ETEC, Heat-Labile Toxin (LT), cholera, Campylobacter, or Shigella, within the past 3 years 9. History of diarrhea during travel to a developing country within the past 3 years 10. History of chronic gastrointestinal illness, including severe dyspepsia, lactose intolerance, or another significant gastrointestinal tract disease (e.g., irritable bowel syndrome, inflammatory bowel syndrome, gastric ulcer disease) 11. Regular use (≥ once weekly) of laxatives, anti-diarrheal agents, anti-constipation agents, or antacid therapies 12. History of major gastrointestinal surgery (uncomplicated laparoscopic appendectomy or cholecystectomy >1-year prior is permitted) 13. Abnormal bowel habits, as defined by \<3 stools per week or >2 stools per day in the past 6 months 14. Use of systemic antibiotics within the past 2 weeks prior to Day 1 15. Use of topical (skin), otic, or ophthalmic antibiotics is acceptable, if those doses are not expected to result in significant systemic absorption levels 16. Use of oral, parenteral or high-dose inhaled within 30 days. High-dose oral or parenteral steroids is defined as ≥20 mg total daily dose, or equivalent dose of other glucocorticoids; high-dose inhaled steroids is defined as >800 μg/day of beclomethasone dipropionate or equivalent.
17. Use of any medication which might affect immune function* within 30 days
*Examples include anti-cancer drugs, immunomodulating monoclonal antibody therapeutics, and rheumatologic therapies 18. Diagnosis of schizophrenia or other major psychiatric disease 19. Alcohol or drug abuse within last 5 years; current smokers or use of nicotine in any form within 6 months prior to screening and until after end of study.
20. Presence of , which could be due to active neoplastic disease or a history of any hematologic (excluding resolved non-melanoma skin cancers), radiation therapy, or primary or secondary immunodeficiencies 21. History of allergy to quinolone (e.g., ciprofloxacin) or sulfa drugs (e.g., trimethoprim-sulfamethoxazole) 22. Known history of seizure disorder (remote history of a childhood seizure disorder which has completely resolved is acceptable) 23. Has consumed any nutrients or drugs with known strong cytochrome P450 3A4/5 (/5) inhibitors or inducers or P-glycoprotein inhibitors or inducers, starting from 14 days prior to Day 1 until the completion of study procedures at the end of study 24. Another medication within 60 days or 5 half-lives, whichever is longer prior to Day 1 25. Participation in an investigational device study within 60 days prior to Day 1 26. Consumption of prescription and over-the-counter medication (including topical medications), traditional Chinese medicine, or herbal medicine, vitamin, mineral, plant, and other dietary supplements within 14 days or 5 half-lives, whichever is longer, prior to Day 1 and throughout the study 27. Consumption of liquids or foods containing grapefruit or cranberry from 7 days prior to Day 1 (Part A) or Check-in (Part B) and throughout the study 28. Consumption of any food containing poppy seeds from 48 h prior to Day 1 (Part A) or Check-in (Part B) and throughout the study 29. Donation of bone marrow or peripheral stem cells within 90 days prior to Day 1 or blood or plasma within 60 days prior to Day 1 30. Participation in strenuous exercise within 72 h prior to Day 1 (Part A) or Check-in (Part B) 31. Consumption of caffeine-containing substances within 72 h prior to Day 1 (Part A) or Check-in (Part B) 32. Occupation involving the handling of ETEC, cholera, or Shigella bacteria 33. Occupation in food handling industry or care of: very young children (\<2 years old), elderly (≥70 years) or immunocompromised 34. Any other criteria which, in the investigator's opinion, would compromise the safety of the study, the ability of a subject to participate, or the results of the study
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.
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.
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
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.
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
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.
Able to have children. For women this usually means from the first period until menopause, unless permanently unable to through surgery; for men, unless permanently sterile. Read who the line is about — participants, women, men, or their partners.
Criteria about it usually ask for contraception during the study and for a time after it.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
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.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Absolute neutrophil count (ANC)
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Postmenopausal
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Reproductive potential
Able to have children. For women this usually means from the first period until menopause, unless permanently unable to through surgery; for men, unless permanently sterile. Read who the line is about — participants, women, men, or their partners.
Criteria about it usually ask for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
QT and QTc
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
CYP3A (CYP3A4) inhibitors and inducers
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Arm 1 Investigational product - Venbeta
Drug: VENBETA6890
Part A Arm 2 Placebo
Drug: Placebo
Part B Arm 2 Particpants receive placebo.
Drug: Placebo
Part B Arm 1 Participants receive Investigational Product
Drug: VENBETA6890
Part A will consist of 1 sentinel dosing group of 2 subjects randomized 1:1 to receive VENBETA6890 and will evaluate VENBETA6890 at dose levels of 15 mg/kg. On Day 1, subjects will receive 15 mg/kg in the morning and a second dose of 15 mg/kg 8 - 12 h later in the outpatient clinic. On Day 2, they will receive a third dose of 15 mg/kg at approximately 8 - 12 h after the last dose on Day 1.
Part A Placebo (saline) will be administered at dose levels of 15 mg/kg. On Day 1, subjects will receive 15 mg/kg in the morning and a second dose of 15 mg/kg 8 - 12 h later in the outpatient clinic. On Day 2, they will receive a third dose of 15 mg/kg at approximately 8 - 12 h after the last dose on Day 1.
Number of Participants who Experience Treatment Emergent Adverse Events
The number of participants who experience treatment emergent adverse events. Severity of Treatment Emergent Adverse Events (TEAEs) are determined by changes in vital signs (VS), Physical examination (PE), and routine clinical laboratory tests.
Time frame: up to day 60
Proportion of Participants who experience treatment emergent adverse events.
Severity of Treatment Emergent Adverse Events (TEAEs) are determined by changes in vital signs (VS), Physical examination (PE), and routine clinical laboratory tests.
Time frame: up to 60 days
Number of participants experiencing diarrhea after enterotoxigenic E.coli (ETEC) challenge
This outcome is measuring the number of participants who experience diarrhea after ETEC challenge. DIARRHEA is defined as at least 1 loose stool (stool consistency of Grade 3 or higher per protocol definition) of ≥ 300 g or at least 2 loose stools totaling ≥ 200 g during any 48-hour period
Time frame: 120 hours post challenge
Proportion of participants experiencing diarrhea after ETEC challenge
This outcome is measuring the proportion of participants who experience diarrhea after ETEC challenge. DIARRHEA is defined as at least 1 loose stool (stool consistency of Grade 3 or higher per protocol definition) of ≥ 300 g or at least 2 loose stools totaling ≥ 200 g during any 48-hour period
Time frame: 120 hours post challenge
Time to onset of diarrhea following ETEC challenge
Time to onset of diarrhea following ETEC challenge
Time frame: 120 hours post challenge
Severity of diarrhea after ETEC challenge
SEVERITY: Based on the highest output over the 120 hours post-challenge, diarrhea will be graded as: * mild (2 or more Grade 3 - 5 stools ≥200 g total within 48 h OR a single Grade 3 - 5 stool of ≥300 g); * moderate (cumulative Grade 3 - 5 stools of ≥1,000 g over 96 h OR Grade 3 - 5 stools of ≥400 mL/g in 24 h OR 4 - 5 Grade 3 - 5 stools in 24 h); * severe (cumulative Grade 3 - 5 stools of ≥ 1,000 g in 48 h OR Grade 3 - 5 stools of ≥ 800 g in 24 h OR \> 5 Grade 3 - 5 stools in 24 h).
Time frame: 120 hours post challenge
Plan to share: No
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