Phase 2
N=32
COVID Protection After Transplant-Immunosuppression Reduction
Kidney Transplant Recipients · Liver Transplant Recipients
Bottom Line
View on ClinicalTrials.gov: NCT05077254 ↗Enrolled (actual)
32
Serious AEs
15.6%
Results posted
Apr 2026
Primary outcome: Primary: The -Fold Change in Antibody Titer (Using the Roche Elecsys® Anti-SARS-CoV-2 S Assay) From Before Receiving the Study Dose of Vaccine to 30 Days After the Study Dose of Vaccine. — 13; 31 dimensionless ratio
Study Design & Population
- Study type
- Interventional
- Phase
- Phase 2
- Interventions
- Pfizer-BioNTech COVID-19 Vaccine 2023-2024 (Biological); Moderna COVID-19 Vaccine 2023-2024 (Biological); SOC IS Regimen (Drug); SOC IS Reduction (Drug)
- Age
- Adult, Older Adult · 18+ yrs
- Sex
- All
- Sponsor
- National Institute of Allergy and Infectious Diseases (NIAID)
- Primary completion
- Feb 2024
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY The -Fold Change in Antibody Titer (Using the Roche Elecsys® Anti-SARS-CoV-2 S Assay) From Before Receiving the Study Dose of Vaccine to 30 Days After the Study Dose of Vaccine. |
13; 31 | — |
| SECONDARY Frequency of Solicited Systemic Allergic Reaction Adverse Events (AEs) to the mRNA-Based COVID-19 Vaccine |
0; 0 | — |
| SECONDARY Proportion of Participants With Local Solicited Adverse Reactions Within 7 Days After Additional Vaccine Dose |
7; 6; 7; 6; 0; 1 | — |
| SECONDARY Proportion of Participants With Systemic Solicited Adverse Reactions Within 7 Days After Additional Vaccine Dose |
4; 3; 0; 1; 0; 1 | — |
| SECONDARY Proportion of Participants With Solicited Potential Allergic Reactions Within 7 Days After Additional Vaccine Dose |
0; 0; 0; 0; 0; 0 | — |
| SECONDARY Frequency of Any Serious Adverse Events (SAEs) During the 30 Days Following the Additional Dose of Vaccine |
2; 0; 16; 14 | — |
| SECONDARY Proportion of Participants Treated for Acute Cell-Mediated and/or Antibody-Mediated Allograft Rejection |
0; 0 | — |
| SECONDARY Proportion of Participants Who Develop de Novo Donor-Specific Anti-Human Leukocyte Antigens (HLA) Antibody |
0; 0 | — |
| SECONDARY Proportion of Participants With Graft Loss |
0; 0 | — |
| SECONDARY Occurrence of Death Among Participants |
0; 0 | — |
| SECONDARY Frequency of Positive SARS-CoV-2 Test Results Using Real-Time Polymerase Chain Reaction (RT-PCR) |
0; 0; 0; 2; 0; 0 | — |
| SECONDARY Occurrence of Symptomatic COVID-19 |
9; 7 | — |
| SECONDARY Occurrence of COVID-19 Requiring Hospitalization |
4; 1; 14; 13 | — |
| SECONDARY Change From Baseline in Anti-SARS-CoV-2 Antibody Levels at Day 30 |
104; 294 | — |
| SECONDARY Change From Baseline in SARS-CoV-2 Antibody Levels |
685; 1878 | — |
| SECONDARY Fold Change in SARS-CoV-2 Antibody Levels: Limited to Participants With Detectable Antibody Levels at Baseline (Day 0). (Values > 1 Represent an Increase From Baseline; Values < 1 Represent a Decrease From Baseline). |
13; 31 | — |
Summary
This study will enroll individuals who have:
* Completed primary series of mRNA COVID-19 vaccine, and
* An antibody response ≤ 2500 U/mL measured at least 30 days after the last dose of vaccine.
This group of patients is at high risk for severe COVID-19 disease due to pharmacologic immunosuppression and a high prevalence of non-transplant risk factors such as obesity and diabetes.
Eligibility Criteria
Inclusion Criteria
Individuals who meet all the following criteria are eligible for enrollment as study participants-
- Able to understand and provide informed consent
- Individual ≥18 years of age.
- Recipient of a kidney or liver transplant ≥12 months prior to enrollment, without allograft rejection in the 6 months preceding enrollment
- Negative for anti-donor human leukocyte antigens (HLA) antibodies at screening (Central Lab Test Determination).
- Currently taking one of the following tacrolimus-based immunosuppressive regimens:
- Tacrolimus plus Mycophenolate Mofetil (MMF) or Mycophenolic Acid (MPA), with or without a corticosteroid
- Tacrolimus with trough ≥ 5ng/mL with or without ≤5 mg of prednisone or equivalent
- Received a minimum of 3 doses of either the Moderna coronavirus infectious disease 19 (COVID-19) vaccine or Pfizer-BioNTech COVID-19 vaccine
- Participant must be ≥ 60 days after completion of primary vaccination or receipt of the most recent booster dose with any authorized or approved monovalent or bivalent COVID-19 vaccine at the time of study vaccine.
- Serum antibody negative or low (titer ≤ 2500 U/mL) at ≥ 30 days from the last dose of mRNA COVID-19 vaccine and ≥ 30 days following receipt of a monoclonal antibody product or convalescent plasma for COVID-19, measured using the Roche Elecsys® anti-SARS-CoV-2 S assay.
- Participant's transplant physician or midlevel practitioner who is clinically licensed to prescribe and manage immunosuppression must confirm the participant's eligibility based on medical history.
Exclusion Criteria
Individuals who meet any of these criteria are not eligible for enrollment as study participants-
- Currently on an immunosuppressive regimen different from the three regimens described in the Inclusion Criteria, for example (but not limited to) those including sirolimus, everolimus, belatacept, or azathioprine
- Recipient of any allograft other than a kidney or liver
- Participant is pregnant
- Any past history of Donor Specific Antibody (DSA) using local site standards
- Prior receipt of the Moderna COVID-19 Vaccine 2023-2024 or Pfizer-BioNTech COVID-19 Vaccine 2023-2024.
- Currently taking any systemic immunosuppressive agent, other than their prescribed transplant immunosuppression
- Known history of severe allergic reaction to any component of an authorized or licensed COVID-19 vaccine
- Thrombotic events, myocarditis, or pericarditis temporally associated with a prior dose of COVID-19 vaccine
- History of heparin-induced thrombocytopenia
- Any change in transplant immunosuppression regimen (drug or dose) in response to suspected or proven rejection within the last 6 months
- More than minimal graft dysfunction, in accordance with study definition
- Receipt of any cellular depleting agent (e.g. antithymocyte globulins (ATG), rituximab, alemtuzumab, Cyclophosphamide) within 12 months preceding enrollment
- Concurrent autoimmune disease at risk for exacerbation with immunosuppression reduction
- Any untreated active infection including BK viremia >10^4 copies
- Infection with human immunodeficiency virus (HIV)
- Recent (within one year) or ongoing treatment for malignancy with the exception of:
- Non- melanomatous skin cancer definitively treated by local therapy, and
- Definitively treated carcinoma-in-situ of the cervix (Stage 0 cervical cancer)
- Treatment or prophylaxis of COVID-19 with a monoclonal antibody product or convalescent plasma within 6 months preceding enrollment, or
- Any past or current medical problems, treatments, or findings which, in the opinion of the investigator, may:
- pose additional risks from participation in the study,
- interfere with the candidate's ability to comply with study requirements, or
- impact the quality or interpretation of the data obtained from the study.
Data sourced from ClinicalTrials.gov (NCT05077254). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.