Long COVIDPhase 2NCT05747534
AT1001 for the Treatment of Long COVID
A Phase 2 study testing Larazotide Acetate in people with Long COVID and Long COVID-19, run by Massachusetts General Hospital at 1 site in United States.
Trial summary
The primary objective of this study is to evaluate the safety and efficacy of Larazotide (AT1001) versus placebo in children and adults 7 to ≤50 years of age who present with symptoms of Long COVID in the presence of SARS-CoV-2 antigenemia. Read more about this study
- Who is it for?
- Ages 7 to 50 years
- Conditions the study is for
- Long COVID, Long COVID-19, Post Acute COVID-19 Syndrome
- What is being tested?
- Larazotide Acetate
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 107 participants
- Where
- 1 siteUnited States
- Study dates
- 31 May 2023to 18 Jun 2026
- Phase
- Phase 2
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 7 to 50 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Age 7 to ≤50 years
- History of SARS-CoV-2 infection, documented by positive PCR and/or antigen test
- Ongoing, worsening, new, or recurrent symptoms present ≥4 weeks after SARS-CoV-2 infection.Symptoms include but are not limited to fatigue, malaise, headache, cognitive impairment, neuropsychiatric symptoms, decreased exercise tolerance, post exertional malaise, dyspnea, cough, chest pain, palpitations, tachycardia, gastrointestinal symptoms, musculoskeletal symptoms, fever, lightheadedness, insomnia and other sleep disturbances, anosmia or dysgeusia, pain, paresthesia, menstrual cycle irregularities, erectile dysfunction.
Who cannot join
- Age ≤6 years or >50 years at time of enrollment
- Pregnancy and/or lactation
- Female participant of childbearing age unwilling to use an acceptable method of birth control for the duration of the study
- Inability to tolerate drug
- Unstable medical conditions or significant co-morbid disease that, by the investigator's determination would make the participant unsuitable for enrollment
- Participation in any other clinical investigation using an experimental drug within 30 days prior to screening
Show all 11Show fewer
- Intent to participate in another clinical study while participating in this clinical trial
- Blood/plasma donation and or blood loss greater than 400 mL within 90 days, or greater than 200 mL within 30 days prior to screening
- Known hypersensitivity to any of the formulation components of AT1001.
- Abnormal baseline liver function as indicated by AST or ALT ≥3 times the upper limit of normal (ULN), or total bilirubin ≥2x ULN for age
- Abnormal baseline renal function, defined as glomerular filtration rate ≤50 mL/min/1.73m2
Trial locations and contacts
1 site in 1 country.
United States1 site
Massachusetts General Hospital
Boston, Massachusetts, 02114
About this study
Official title: Phase 2a Randomized, Double-Blind, Placebo-Controlled, Multi-Center Study to Evaluate the Safety and Efficacy of Larazotide (AT1001) for the Treatment of Long COVID in Children and Adults
The primary objective of this study is to evaluate the safety and efficacy of Larazotide (AT1001) versus placebo in children and adults 7 to ≤50 years of age who present with symptoms of Long COVID in the presence of SARS-CoV-2 antigenemia. AT1001 (n=100) or placebo (n=50) will be administered orally four times a day (QID) for 21 days.
Read the detailed description
This is a Phase 2a randomized, double-blind, placebo-controlled clinical trial to evaluate the safety and efficacy of AT1001 for use in children and adults with symptoms of Long COVID. Eligible participants (N= 150) will be treated with AT1001 (n= 100) or matching placebo (n= 50) orally four times a day (QID for 21 days). The study will consist of two phases:
- Baseline Visit and Treatment phase
After confirming subject eligibility, a licensed physician investigator will obtain informed consent. Subjects will be asked to complete baseline surveys (SBQ™-LC, PedsQL, and Symptom Severity Survey) to assess organ involvement and symptom severity. A venous blood sample will be obtained to, among other things, assess for SARS COV-2 antigenemia (such as Spike protein) and obtain a comprehensive metabolic panel and liver function test. Patients who meet inclusion criteria will be treated with AT1001 or matching placebo at a dose of 250 μg or 500 μg for 21 days. Drug dose will be determined by weight: patients <25.0 kg will receive 250 μg of Larazotide or Placebo, and patients ≥25.0 kg will receive 500 μg of Larazotide or Placebo. Randomization and initial dosing will occur on Visit 1 (Day 1). Visits will then occur on a weekly basis during the treatment phase and will consist of data and/or specimen collection. Visit 2 (Week 1) and Visit 3 (Week 2) will take place virtually and will not involve sample collection. Once the subject has completed 21 days of dosing, Visit 4 (Week 3) will take place in person and require the collection of blood, stool and nasal swabs.
II. Follow-up phase
Patients will have two additional virtual follow-up visits after completing their 21-day course of treatment with the study drug. The first follow up visit will occur one week after completing the study drug (ie. at week 4), and the second will occur one month later (ie. at week 8). Week 8 visit will serve as the end of study visit. Biospecimens will not be collected during the follow-up phase.
Safety monitoring, including physical examination, vitals, and clinical laboratory testing will be performed during the baseline phase and after completion of treatment. Adverse events and concomitant medications will be recorded during the entire study.
Total duration of the participants' participation in the study is approximately 8 weeks (with 21 days treatment period). Total duration of the study is projected to be roughly 42 months, dependent on enrollment timeline.
- Being tested
- Larazotide Acetate, Placebo
- Keywords
- SARS-CoV-2, Long COVID, Pediatrics
- Medical subject headings
- Post-Acute COVID-19 Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Larazotide AcetateDrug
Also called AT1001
AT1001 (Larazotide) is a locally acting, non-systemic, octapeptide inhibitor of the zonulin receptor that has shown efficacy in a large variety of animal models of inflammation. The effectiveness of AT1001 in controlling paracellular permeability as a tight junction regulator has been widely demonstrated in animal models both in vitro and in vivo. In MIS-C, prolonged presence of SARS-CoV-2 in the GI tract leads to release of zonulin, a biomarker of intestinal permeability, with subsequent trafficking of SARS-CoV-2 antigens into the bloodstream, leading to hyperinflammation (Yonker, et. al. 2021). Five children treated with AT1001 (through an Emergency Investigational New Drug request authorized by the FDA) displayed a decrease in plasma SARS-CoV-2 Spike antigen levels, inflammatory markers, and symptom improvement superior to that achieved with the current standard of treatment for MIS-C (ie. immunoglobulin, systemic steroids) (Yonker, et. al. 2021) (Yonker, et. al. 2022)
PlaceboDrug
Matching placebo will be administered orally four times a day (QID) to participants in the placebo arm.
| Study group | Role | What they receive |
|---|---|---|
| Larazotide Acetate (AT1001) | Experimental | Subjects will receive 250 or 500 µg of Larazotide Acetate orally four times a day (QID) for 21 days. Subjects <25.0 kg will receive 250 µg dose of Larazotide Acetate (AT1001), and subjects ≥25.0 kg will receive 500 µg dose of Larazotide Acetate (AT1001). Receives: Drug: Larazotide Acetate |
| Placebo | Placebo comparator | Subjects will receive 250 or 500 µg of placebo orally four times a day (QID) for 21 days. Subjects <25.0 kg will receive 250 µg dose of placebo and subjects ≥25.0 kg will receive 500 µg dose of placebo. Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Adverse Event Profiling and Time to Symptom Resolution
The primary objective of this study is to evaluate the safety and efficacy of Larazotide (AT1001) versus placebo in children and young adults 7 to ≤50 years of age who present with symptoms of Long COVID. Safety will be assessed by means of adverse event monitoring, and efficacy will be evaluated using the Symptom Burden Questionnaire™ for Long COVID (SBQ™-LC) survey. Additional surveys will be used to monitor symptoms, quality of life and limitation of activities before, during and after treatment with Larazotide or Placebo.
Measured: 8 weeks
Secondary outcomes (1)
Cytokine profiling, Antigen Testing and Humoral and Cellular Responses
The secondary objective of this study is to characterize the inflammatory response observed in children and young adults 7 to ≤21 years of age with Long COVID and SARS-CoV-2 antigenemia. To assess inflammatory responses, blood, stool and nasal epithelial specimens will be obtained at baseline prior to treatment with Larazotide or Placebo, and at completion of the study's treatment phase (21 days). Inflammatory responses will be evaluated by means of antigen testing, cytokine profiling, among others.
Measured: 21 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Feb 2023
- Study start31 May 2023
- Primary completion18 Jun 2026
- Study completion18 Jun 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Long COVIDStudies of the same condition, open and under way.
- More trials run by Massachusetts General HospitalThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Drug arm Placebo arm Subjects \<25.0 kg will receive 250 µg of AT1001 or placebo, and subjects ≥25.0 kg will receive 500 µg of AT1001 or placebo
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 107 participants (actual)
Sponsor and investigators
- Lead sponsor
- Massachusetts General Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Lael Yonker, M.D., Massachusetts General Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05747534
- Sponsor's protocol ID
- 2023P000240
- Status last verified
- Aug 2026
- First submitted
- 24 Feb 2023
- Last updated
- 18 Aug 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 18 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Phase 2a Randomized, Double-Blind, Placebo-Controlled, Multi-Center Study to Evaluate the Safety and Efficacy of Larazotide (AT1001) for the Treatment of Long COVID in Children and Adults
- ClinicalTrials.gov ID
- NCT05747534
- Acronym / sponsor ID
- 2023P000240
- Keywords
- SARS-CoV-2, Long COVID, Pediatrics
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 107 participants (actual)
- Lead sponsor
- Massachusetts General HospitalUniversity, hospital or other
- Study start
- 31 May 2023 (actual)
- Primary completion
- 18 Jun 2026 (actual)
- Study completion
- 18 Jun 2026 (actual)
- First posted
- 28 Feb 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The primary objective of this study is to evaluate the safety and efficacy of Larazotide (AT1001) versus placebo in children and adults 7 to ≤50 years of age who present with symptoms of Long COVID in the presence of SARS-CoV-2 antigenemia. AT1001 (n=100) or placebo (n=50) will be administered orally four times a day (QID) for 21 days.
Detailed description
This is a Phase 2a randomized, double-blind, placebo-controlled clinical trial to evaluate the safety and efficacy of AT1001 for use in children and adults with symptoms of Long COVID. Eligible participants (N= 150) will be treated with AT1001 (n= 100) or matching placebo (n= 50) orally four times a day (QID for 21 days). The study will consist of two phases:
- Baseline Visit and Treatment phase
After confirming subject eligibility, a licensed physician investigator will obtain informed consent. Subjects will be asked to complete baseline surveys (SBQ™-LC, PedsQL, and Symptom Severity Survey) to assess organ involvement and symptom severity. A venous blood sample will be obtained to, among other things, assess for SARS COV-2 antigenemia (such as Spike protein) and obtain a comprehensive metabolic panel and liver function test. Patients who meet inclusion criteria will be treated with AT1001 or matching placebo at a dose of 250 μg or 500 μg for 21 days. Drug dose will be determined by weight: patients <25.0 kg will receive 250 μg of Larazotide or Placebo, and patients ≥25.0 kg will receive 500 μg of Larazotide or Placebo. Randomization and initial dosing will occur on Visit 1 (Day 1). Visits will then occur on a weekly basis during the treatment phase and will consist of data and/or specimen collection. Visit 2 (Week 1) and Visit 3 (Week 2) will take place virtually and will not involve sample collection. Once the subject has completed 21 days of dosing, Visit 4 (Week 3) will take place in person and require the collection of blood, stool and nasal swabs.
II. Follow-up phase
Patients will have two additional virtual follow-up visits after completing their 21-day course of treatment with the study drug. The first follow up visit will occur one week after completing the study drug (ie. at week 4), and the second will occur one month later (ie. at week 8). Week 8 visit will serve as the end of study visit. Biospecimens will not be collected during the follow-up phase.
Safety monitoring, including physical examination, vitals, and clinical laboratory testing will be performed during the baseline phase and after completion of treatment. Adverse events and concomitant medications will be recorded during the entire study.
Total duration of the participants' participation in the study is approximately 8 weeks (with 21 days treatment period). Total duration of the study is projected to be roughly 42 months, dependent on enrollment timeline.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- Drug arm Placebo arm Subjects <25.0 kg will receive 250 µg of AT1001 or placebo, and subjects ≥25.0 kg will receive 500 µg of AT1001 or placebo
| Arm | Type | Receives |
|---|---|---|
| Larazotide Acetate (AT1001) | Experimental | Drug: Larazotide AcetateSubjects will receive 250 or 500 µg of Larazotide Acetate orally four times a day (QID) for 21 days. Subjects <25.0 kg will receive 250 µg dose of Larazotide Acetate (AT1001), and subjects ≥25.0 kg will receive 500 µg dose of Larazotide Acetate (AT1001). |
| Placebo | Placebo comparator | Drug: PlaceboSubjects will receive 250 or 500 µg of placebo orally four times a day (QID) for 21 days. Subjects <25.0 kg will receive 250 µg dose of placebo and subjects ≥25.0 kg will receive 500 µg dose of placebo. |
Who may qualify
- Ages
- 7 to 50 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (3 listed)
- Age 7 to ≤50 years
- History of SARS-CoV-2 infection, documented by positive PCR and/or antigen test
- Ongoing, worsening, new, or recurrent symptoms present ≥4 weeks after SARS-CoV-2 infection.Symptoms include but are not limited to fatigue, malaise, headache, cognitive impairment, neuropsychiatric symptoms, decreased exercise tolerance, post exertional malaise, dyspnea, cough, chest pain, palpitations, tachycardia, gastrointestinal symptoms, musculoskeletal symptoms, fever, lightheadedness, insomnia and other sleep disturbances, anosmia or dysgeusia, pain, paresthesia, menstrual cycle irregularities, erectile dysfunction.
Key exclusion criteria (11 listed)
- Age ≤6 years or >50 years at time of enrollment
- Pregnancy and/or lactation
- Female participant of childbearing age unwilling to use an acceptable method of birth control for the duration of the study
- Inability to tolerate drug
- Unstable medical conditions or significant co-morbid disease that, by the investigator's determination would make the participant unsuitable for enrollment
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Larazotide AcetateAlso: AT1001AT1001 (Larazotide) is a locally acting, non-systemic, octapeptide inhibitor of the zonulin receptor that has shown efficacy in a large variety of animal models of inflammation. The effectiveness of AT1001 in controlling paracellular permeability as a tight junction regulator has been widely demonstrated in animal models both in vitro and in vivo. In MIS-C, prolonged presence of SARS-CoV-2 in the GI tract leads to release of zonulin, a biomarker of intestinal permeability, with subsequent trafficking of SARS-CoV-2 antigens into the bloodstream, leading to hyperinflammation (Yonker, et. al. 2021). Five children treated with AT1001 (through an Emergency Investigational New Drug request authorized by the FDA) displayed a decrease in plasma SARS-CoV-2 Spike antigen levels, inflammatory markers, and symptom improvement superior to that achieved with the current standard of treatment for MIS-C (ie. immunoglobulin, systemic steroids) (Yonker, et. al. 2021) (Yonker, et. al. 2022) | Drug | Larazotide Acetate (AT1001) |
| PlaceboMatching placebo will be administered orally four times a day (QID) to participants in the placebo arm. | Drug | Placebo |
Primary outcome
Adverse Event Profiling and Time to Symptom Resolution
Time frame: 8 weeks
The primary objective of this study is to evaluate the safety and efficacy of Larazotide (AT1001) versus placebo in children and young adults 7 to ≤50 years of age who present with symptoms of Long COVID. Safety will be assessed by means of adverse event monitoring, and efficacy will be evaluated using the Symptom Burden Questionnaire™ for Long COVID (SBQ™-LC) survey. Additional surveys will be used to monitor symptoms, quality of life and limitation of activities before, during and after treatment with Larazotide or Placebo.
1 secondary outcome
Cytokine profiling, Antigen Testing and Humoral and Cellular Responses
Time frame: 21 days
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Aug 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Larazotide Acetate in people with Long COVID and Long COVID-19, run by Massachusetts General Hospital at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 18 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Adverse Event Profiling and Time to Symptom Resolution (time frame: 8 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Aug 2026.