ClinicalTrials.gov
ClinicalTrials.gov Menu

Phase 1 Study of dmLT ID Vaccination in Healthy Adults

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT02531685
Recruitment Status : Recruiting
First Posted : August 24, 2015
Last Update Posted : October 13, 2017
Sponsor:
Information provided by (Responsible Party):
National Institute of Allergy and Infectious Diseases (NIAID)

Brief Summary:
Many infectious pathogens, like ETEC, initiate infection by first interacting with the gut mucosal surfaces of their human host. Consequently, vaccination strategies that can better stimulate protective mucosal immunity are needed if we are to effectively control the large number of intestinal pathogens that cause morbidity and mortality in humans. The LT toxin of ETEC is a unique antigen in that it also has inherent mucosal adjuvant properties for co-administered antigens. Thus, this protein has the potential to be both a stand-alone vaccine as well as a mucosal adjuvant for other co-administered vaccine antigens. The primary objective is to assess the safety and tolerability of dmLT vaccine when administered in three doses intradermally over a range of dosages in healthy adult subjects.

Condition or disease Intervention/treatment Phase
Gastroenteritis Escherichia Coli Other: Placebo Biological: Recombinant Double Mutant Heat-Labile Toxin LT(R192G/L211A) (dmLT) Oral entertoxigenic Escherichia coli (ETEC) Vaccine Phase 1

Detailed Description:
This is a randomized, double-blinded, single site outpatient Phase 1 study in healthy adults to determine the safety and immunogenicity of an ETEC candidate vaccine, attenuated recombinant dmLT from ETEC, administered by the ID route. The sample size has been determined based on the historic sample, not on power calculations. The study will involve 99 subjects (83 vaccinees and 16 placebo controls) in 4 consecutive cohorts of 16 individuals each (13 vaccinees and 3 placebo controls) and the final cohort of 35 (31 vaccinees and 4 placebos) subjects. A total of 16 subjects (to retain 10 vaccinees and 1 placebo evaluable subjects) in each cohorts 1-4 will initially be recruited, 13 subjects each will receive three separate doses of dmLT intradermally at 1, 22 and 43-day, and 3 subjects in each cohort will receive three doses of a placebo (saline) in a blinded fashion. As this is an outpatient study, subjects will receive their vaccinations and remain in clinic for observation for a minimum of 30 minutes. Safety data will be reviewed by Safety Monitoring Team or Committee. Subjects may be replaced to ensure 10 evaluable subjects in each single cohort, as defined by receiving all 3 vaccine doses. If replacement subjects will be included if needed and they will be randomized per cohort as a single group to include 1 subject to receive placebo to maintain the blind and ensure there are one placebos in each cohort. Final confirmatory cohort will include up to 35 vaccinees randomly selected to receive either 1, 2 or 3 vaccine doses or placebo. The study duration is approximately 1.5-2 years, including 6 months of follow-up and approximately 9 months for subject duration. The Primary Objective is to assess the safety and tolerability of dmLT vaccine when administered in three intradermal doses over a range of dosages levels in healthy adult subjects. The Secondary objectives assess long-term safety follow-up from immunization through Month 6 months post last vaccination, following three ID doses of dmLT vaccine over a range of dosages levels evaluate dmLT-specific immune response by assays.

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 99 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Prevention
Official Title: A Phase 1 Double-Blind Placebo-Control Dose Escalating Study to Evaluate the Safety and Immunogenicity of Double Mutant Heat-Labile Toxin LTR192G/L211A (dmLT) From Enterotoxigenic Escherichia Coli (ETEC) by Intradermal (ID) Vaccination in Healthy Adults
Actual Study Start Date : June 2, 2016
Estimated Primary Completion Date : July 7, 2018
Estimated Study Completion Date : December 29, 2018

Resource links provided by the National Library of Medicine

U.S. FDA Resources

Arm Intervention/treatment
Experimental: Cohort 1
13 subjects receive 0.1 mcg dmLT intradermally on days 1, 22 and 43. 3 subjects receive placebo.
Other: Placebo
Placebo: 0.9% Sodium Chloride injection. 3 subjects in each cohort receive placebo injection intradermally on days 1, 22 and 43.
Biological: Recombinant Double Mutant Heat-Labile Toxin LT(R192G/L211A) (dmLT) Oral entertoxigenic Escherichia coli (ETEC) Vaccine
LT(R192G/L211A), or dmLT is formulated as a freeze-dried (lyophilized), white to off-white cake, containing 700mcg of vaccine protein in a 3 ml, multi-dose. Cohorts 1-4 receive doses of 0.1, 0.3, 1.0 and 2.0 mcg respectively, intradermally on days 1, 22 and 43. Cohort 5 receives a TBD dose on days 1, 22, and 43
Experimental: Cohort 2
13 subjects receive 0.3 mcg dmLT intradermally on days 1, 22 and 43. 3 subjects receive placebo.
Other: Placebo
Placebo: 0.9% Sodium Chloride injection. 3 subjects in each cohort receive placebo injection intradermally on days 1, 22 and 43.
Biological: Recombinant Double Mutant Heat-Labile Toxin LT(R192G/L211A) (dmLT) Oral entertoxigenic Escherichia coli (ETEC) Vaccine
LT(R192G/L211A), or dmLT is formulated as a freeze-dried (lyophilized), white to off-white cake, containing 700mcg of vaccine protein in a 3 ml, multi-dose. Cohorts 1-4 receive doses of 0.1, 0.3, 1.0 and 2.0 mcg respectively, intradermally on days 1, 22 and 43. Cohort 5 receives a TBD dose on days 1, 22, and 43
Experimental: Cohort 3
13 subjects receive 1.0 mcg dmLT intradermally on days 1, 22 and 43. 3 subjects receive placebo.
Other: Placebo
Placebo: 0.9% Sodium Chloride injection. 3 subjects in each cohort receive placebo injection intradermally on days 1, 22 and 43.
Biological: Recombinant Double Mutant Heat-Labile Toxin LT(R192G/L211A) (dmLT) Oral entertoxigenic Escherichia coli (ETEC) Vaccine
LT(R192G/L211A), or dmLT is formulated as a freeze-dried (lyophilized), white to off-white cake, containing 700mcg of vaccine protein in a 3 ml, multi-dose. Cohorts 1-4 receive doses of 0.1, 0.3, 1.0 and 2.0 mcg respectively, intradermally on days 1, 22 and 43. Cohort 5 receives a TBD dose on days 1, 22, and 43
Experimental: Cohort 4
13 subjects receive 2.0 mcg dmLT intradermally on days 1, 22 and 43. 3 subjects receive placebo.
Other: Placebo
Placebo: 0.9% Sodium Chloride injection. 3 subjects in each cohort receive placebo injection intradermally on days 1, 22 and 43.
Biological: Recombinant Double Mutant Heat-Labile Toxin LT(R192G/L211A) (dmLT) Oral entertoxigenic Escherichia coli (ETEC) Vaccine
LT(R192G/L211A), or dmLT is formulated as a freeze-dried (lyophilized), white to off-white cake, containing 700mcg of vaccine protein in a 3 ml, multi-dose. Cohorts 1-4 receive doses of 0.1, 0.3, 1.0 and 2.0 mcg respectively, intradermally on days 1, 22 and 43. Cohort 5 receives a TBD dose on days 1, 22, and 43
Experimental: Cohort 5
Up to 31 subjects receive TBD mcg dmLT intradermally on days 1, 22 and 43. 4 subjects receive placebo.
Other: Placebo
Placebo: 0.9% Sodium Chloride injection. 3 subjects in each cohort receive placebo injection intradermally on days 1, 22 and 43.
Biological: Recombinant Double Mutant Heat-Labile Toxin LT(R192G/L211A) (dmLT) Oral entertoxigenic Escherichia coli (ETEC) Vaccine
LT(R192G/L211A), or dmLT is formulated as a freeze-dried (lyophilized), white to off-white cake, containing 700mcg of vaccine protein in a 3 ml, multi-dose. Cohorts 1-4 receive doses of 0.1, 0.3, 1.0 and 2.0 mcg respectively, intradermally on days 1, 22 and 43. Cohort 5 receives a TBD dose on days 1, 22, and 43



Primary Outcome Measures :
  1. Occurrence of solicited adverse events (AEs) [ Time Frame: 7 Days following each vaccination ]
  2. Occurrence of vaccine-related, non-solicited adverse events (AEs) [ Time Frame: Day 43 through 73 ]

Secondary Outcome Measures :
  1. Occurrence of vaccine-related serious adverse events (SAEs) [ Time Frame: Day 1 through 6 months after 3rd vaccination ]
  2. Occurrence of vaccine-related, non-solicited adverse events (AEs) [ Time Frame: Day 1 through 6 months after 3rd vaccination ]
  3. Proportion of subjects with > /=2-fold rise from the baseline in dmLT-specific IgA-ALS assays [ Time Frame: Day 1 through Day 99 ]
  4. Proportion of subjects with > /=2-fold rise from the baseline in dmLT-specific IgG-ALS assays [ Time Frame: Day 1 through Day 99 ]
  5. Proportion of subjects with > /=4-fold rise from the baseline in dmLT-specific fecal IgA assays [ Time Frame: Day 1 through Day 99 ]
  6. Proportion of subjects with > /=4-fold rise from the baseline in dmLT-specific fecal IgG titer [ Time Frame: Day 1 through Day 99 ]
  7. Proportion of subjects with > /=4-fold rise from the baseline in dmLT-specific serum IgA titer [ Time Frame: Day 1 through Day 99 ]
  8. Proportion of subjects with > /=4-fold rise from the baseline in dmLT-specific serum IgG assays [ Time Frame: Day 1 through Day 99 ]
  9. Proportion of subjects with > /=4-fold rise from the baseline in dmLT-specific toxin neutralization assays [ Time Frame: Day 1 through Day 99 ]
  10. Proportion of subjects with >/=4-fold rise from the baseline in dmLT-specific salivary IgA assays (cohort 5 only) [ Time Frame: Day 1 through Day 99 ]
  11. Proportion of subjects with >8 IgA- or IgG-ASC/10^6 peripheral blood mononuclear cells (PBMCs) [ Time Frame: Day 1 through Day 99 ]
  12. Proportion of subjects with IgA dmLT-specific circulating ASC expressing gut homing receptors (integrin alpha4beta7 in the absence or presence of CD62L) [ Time Frame: Day 1 through Day 99 ]
  13. Proportion of subjects with IgG dmLT-specific circulating ASC expressing gut homing receptors (integrin alpha4beta7 in the absence or presence of CD62L) in cohort 5 only. [ Time Frame: Day 1 through Day 99 ]
  14. Proportion of the subjects with B or T cell memory determined by EliSpot [ Time Frame: Day 1 through Day 99 ]


Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.


Ages Eligible for Study:   18 Years to 45 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

- Male or female ages 18-45, inclusive. - Provide written informed consent before initiation of any study procedures. - Are in general good health. --As defined by being without (a) significant medical illness, (b) clinically significant physical examination findings, including vitals, as determined by the PI, and (c) screening laboratory values outside the site's normal limits. - Within 46 days of vaccination, have normal screening laboratories, per Appendix B. --Screening labs include white blood cells (WBCs) , hemoglobin (Hgb), platelets, absolute neutrophil count (ANC), sodium, potassium, bicarbonate, blood urea nitrogen (BUN), creatinine, alanine aminotransferase (ALT), aspartate aminotransferase (AST). - Have normal screening laboratories for urine protein. Trace protein is acceptable. -HgbA1C <6.5% at screening. - Agrees to complete all study visits and procedures and to provide a screening stool sample. - Female subjects must be of non-childbearing potential or if of childbearing potential, must be using an effective method of birth control or must be abstinent. -- Non-childbearing potential is defined as surgically sterile or postmenopausal for > one year. --Effective methods of birth control include the use of hormonal or barrier birth control such as implants, injectable contraceptives, combined oral contraceptives, intrauterine devices [IUDs], cervical sponges, diaphragms, or condoms with spermicidal agents within 2 months of vaccination. Female subjects must be using an effective method of birth control or practice abstinence and must agree to continue such precautions during the study and for 30 days after the Day 43 study visit. -- A woman is eligible if she is monogamous with a vasectomized male - Male subjects must agree not to father a child for 30 days after the Day 43 study visit. - Agrees not to participate in another clinical trial during the study period. - Agrees not to donate blood to a blood bank for 12 months after receiving the vaccine. - Potential subjects must be willing to adhere to the following prohibitions and restrictions on exercise during the course of the study to be eligible for participation. -- Strenuous exercise (e.g., long distance running > 5km/day, weight lifting, or any physical activity to which the subject is not accustomed) is to be avoided for at least 72 hours prior to each study drug administration (and the Follow-up visit).

Exclusion Criteria:

- Women who are pregnant or lactating or have a positive serum pregnancy test at screening or positive urine pregnancy test on vaccination days. -Abnormal vital signs, defined as: --Hypertension (systolic blood pressure >140 mm Hg or diastolic blood pressure >90 mm Hg) at rest on 2 separate days; or -- Palpated heart rate <55 or >100 beats/minute at rest on 2 separate days*; or *If heart rate between 45 and 55, subjects may be enrolled with an EKG that demonstrates normal sinus rhythm and does not document conduction disorders. -- Oral Temperature >=38.0°C (100.4°F) - Symptoms of an acute self-limited illness, including an oral temperature >=38.0°C (100.4°F), such as an upper respiratory infection or gastroenteritis within 7 days of administration of dmLT. - Positive hepatitis C, or HIV serology or positive hepatitis B serology not consistent with prior hepatitis B immunization. - Have a positive urine drug screen for opiates. - History of antimicrobial treatment in the 2 weeks before any administration of dmLT. - Received previous experimental E. coli, LT, or cholera vaccines or live E. coli or Vibrio cholera challenges; or previous known infections with cholera or diarrheagenic E. coli. - Abnormal routine bowel habits as defined by fewer than three stools per week or more than two stools per day in the past 6 months. - History of chronic gastrointestinal illness. -- This includes severe dyspepsia (mild or moderate heartburn or epigastric pain occurring no more than three times per week is permitted), or other significant gastrointestinal tract disease. - Regular use (weekly or more often) of laxatives, anti-diarrheal, anti-constipation, or antacid therapy. - History of major gastrointestinal surgery, excluding uncomplicated appendectomy or cholecystectomy. - Long-term use of oral steroids, parenteral steroids, or high-dose inhaled steroids (>800 mcg/day of beclomethasone dipropionate or equivalent) within the preceding 6 months. -- Long-term use is defined as longer than 14 days. Nasal and topical steroids are allowed. -Have a diagnosis of schizophrenia or other major psychiatric diagnosis. - Are receiving impermissible psychiatric drugs. -- The following psychiatric drugs are not permitted: aripiprazole, clozapine, ziprasidone, haloperidol, molindone, loxapine, thioridazine, thiothixene, pimozide, fluphenazine, risperidone, mesoridazine, quetiapine, trifluoperazine, chlorprothixene, chlorpromazine, perphenazine, olanzapine, carbamazepine, divalproex sodium, lithium carbonate, or lithium citrate. NOTE: Subjects who are receiving a single antidepressant drug and are stable for at least 3 months before enrollment without de-compensating symptoms are allowed to be enrolled in the study. - History of receiving Ig or other blood product within the 3 months before enrollment in this study. - Subjects who have traveled to an ETEC-endemic area within the past 3 years or have been raised in a cholera or ETEC endemic area. -- Defined as Africa, Middle East, South Asia, or Central or South America - Subjects who plan to travel to an ETEC-endemic area during the long-term safety follow-up period (6 months after last vaccination) of the study. -- Defined as Africa, Middle East, South Asia, or Central or South America - Received any licensed vaccine prior to enrollment in this study or plans to receive any licensed vaccine after any study vaccination. -- Inactivated vaccines may not have been received within 2 weeks of enrollment or within 2 weeks after any study vaccination. Live vaccines may not have been received within 4 weeks of enrollment, while on study, or within 4 weeks of final study visit. - An a cute or chronic medical condition that, in the opinion of the investigator, would render administration of dmLT unsafe or would interfere with the evaluation of responses. -- This includes, but is not limited to: known or suspected immunodeficiency, known chronic liver disease, significant renal disease, unstable or progressive neurological disorders, history of diabetes, cancer (other than a healed skin lesion), heart disease (in the hospital for a heart attack, history of irregular heart beat or have had postural hypotension in the past year, unconsciousness (other than a single brief concussion), seizures (other than with fever when subject was a child <5 years old), asthma requiring treatment with inhaler or medication in the prior 2 years, autoimmune disease or eating disorder, and transplant recipients. - Have received experimental products within 30 days prior to study entry or plan to receive experimental products at any time during the study. - History of alcohol or drug abuse in the last 5 years. - Plans to travel outside of the USA in the time between study vaccination and 4 weeks following the final vaccination. - Any condition that would, in the opinion of the Site Investigator, place the subject at an unacceptable risk of injury or render the subject unable to meet the requirements of the protocol. - Use of prescription or over-the-counter (OTC) anti-inflammatory medications 48 hours prior to receiving the investigational product. -- This includes medications that contain naproxen, aspirin, ibuprofen, and other non-steroidal anti-inflammatory drugs. - Subjects with autoimmune disorders, chronic inflammatory disorders or neurological disorders with a potential autoimmune correlation. - Known allergies to study compound or components of the study vaccine. - Special populations, e.g., non-English speakers, children, illiterate or non-writing individuals, vulnerable populations.


Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02531685


Contacts
Contact: David I Bernstein 15136367625 david.bernstein@cchmc.org

Locations
United States, Ohio
Cincinnati Children's Hospital Medical Center - Infectious Diseases Recruiting
Cincinnati, Ohio, United States, 45206-1613
Sponsors and Collaborators
National Institute of Allergy and Infectious Diseases (NIAID)

Responsible Party: National Institute of Allergy and Infectious Diseases (NIAID)
ClinicalTrials.gov Identifier: NCT02531685     History of Changes
Other Study ID Numbers: 13-0013
HHSN272201300022I
First Posted: August 24, 2015    Key Record Dates
Last Update Posted: October 13, 2017
Last Verified: July 19, 2017

Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
Product Manufactured in and Exported from the U.S.: No

Keywords provided by National Institute of Allergy and Infectious Diseases (NIAID):
dmLT
Enteric
Escherichia coli Infections
Shigella
Toxin LTR192G/L211A

Additional relevant MeSH terms:
Gastroenteritis
Gastrointestinal Diseases
Digestive System Diseases
Vaccines
Immunologic Factors
Physiological Effects of Drugs