Unbound Tacrolimus in Pregnant Uterus Transplant RecipientsNCT07422012
Tacrolimus in Pregnancy
An observational study of Unbound Tacrolimus in Pregnant Uterus Transplant Recipients and Whole Blood Tacrolimus in Pregnant Uterus Transplant Recipients, run by Baylor Research Institute at 1 site in United States.
Trial summary
To create a formula that adjusts tacrolimus blood levels. This is needed because pregnant patients have higher levels of unbound tacrolimus. The adjusted formula will give a more accurate measure of the active drug in pregnant uterus transplant patients. Read more about this study
- Who is it for?
- Ages 18 to 50 years, women only
- Conditions the study is for
- Unbound Tacrolimus in Pregnant Uterus Transplant Recipients, Whole Blood Tacrolimus in Pregnant Uterus Transplant Recipients
- What is being tested?
- Modeling of unbound and whole blood tacrolimus in pregnant uterus transplant recipients
- How many people
- 55 participants
- Where
- 1 siteUnited States
- Study dates
- 31 May 2026to Mar 2028
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 18 to 50 years
- Women only
- Adult
Study population: Uterus transplant recipient over 18 years of age receiving tacrolimus for immunosuppression.
Who may be able to join
- Uterus transplant recipient
- 18 to 50 years of age
- receiving tacrolimus for immunosuppression.
Who cannot join
- Individuals who have not had a uterine transplant
- individuals over 50 years old
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site
Baylor University Center of Dallas
Dallas, Texas, 75246
About this study
Official title: Optimization of Tacrolimus Management During Pregnancy: Modeling of Unbound and Whole Blood Tacrolimus in Pregnant Uterus Transplant Recipients
To create a formula that adjusts tacrolimus blood levels. This is needed because pregnant patients have higher levels of unbound tacrolimus. The adjusted formula will give a more accurate measure of the active drug in pregnant uterus transplant patients.
Read the detailed description
A non-linear mixed effects model describing tacrolimus exposure in pregnant and non-pregnant subjects will be developed using prospectively collected de-identified data from pregnant uterus transplant recipients at BUMC.
The model will be analyzed to develop an estimating equation for tacrolimus unbound concentrations from whole blood concentrations, albumin and hematocrit during each trimester of pregnancy.
The estimating equation will then be applied to data from uterus transplant recipients enrolled in this study and retrospectively to uterus recipients transplanted since October 2020 to clinically validate the findings.
- Conditions
- Unbound Tacrolimus in Pregnant Uterus Transplant Recipients, Whole Blood Tacrolimus in Pregnant Uterus Transplant Recipients
- Being tested
- Modeling of unbound and whole blood tacrolimus in pregnant uterus transplant recipients
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Modeling of unbound and whole blood tacrolimus in pregnant uterus transplant recipientsBiological
Develop an estimating equation to correct tacrolimus whole blood concentrations given the known increase in the unbound tacrolimus concentration in pregnant patients to obtain a more accurate picture of active tacrolimus exposure (unbound drug) in pregnant uterus transplant recipients.
| Study group | Role | What they receive |
|---|---|---|
| Pregnant Individuals | Individuals who had a uterus transplant that are using tacrolimus during pregnancy. Receives: Biological: Modeling of unbound and whole blood tacrolimus in pregnant uterus transplant recipients |
What is being measured
The primary outcome is the main question the study is designed to answer.
Understanding Tacrolimus Levels in Pregnancy
Develop a joint non-linear mixed effect population pharmacokinetic model describing bound and unbound tacrolimus pharmacokinetics in pregnant subjects.
Measured: 2nd (weeks 13-26) and 3rd (weeks 27-40) trimester of pregnancy
Secondary outcomes (2)
Adjusting Tacrolimus Blood Levels by Trimester
Create an equation to adjust whole blood tacrolimus concentrations for changes in drug binding during each trimester at the point of care
Measured: 2nd (weeks 13-26) and 3rd (weeks 27-40) trimester of pregnancy
Linking the Mixed Pharmacokinetic Model and the Equation to Adjust Whold Blood Tacrolimus Concentrations to Active Tacrolimus Levels During and After Pregnancy
Correlate clinical outcomes with estimated unbound tacrolimus concentrations from uterus transplant recipients during each trimester and outside of pregnancy using whole blood trough concentrations and the model developed in Outcome 1
Measured: 1 week postpartum, 4 weeks, 5 weeks and 6 weeks postpartum
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Feb 2026
- Study start31 May 2026 (estimated)
- Primary completionFeb 2028 (estimated)
- Study completionMar 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (10)Papers the sponsor has linked to this study.
- Other trials for Unbound Tacrolimus in Pregnant Uterus Transplant RecipientsStudies of the same condition, open and under way.
- More trials run by Baylor Research InstituteThe 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
- Observational
- Observational model
- Case only
- Time perspective
- Prospective
- Enrolment
- 55 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Baylor Research Institute
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Nicole Wilson, Pharmacist, Principal investigator, Baylor Scott and White Health
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07422012
- Sponsor's protocol ID
- 026-140
- Status last verified
- Apr 2026
- First submitted
- 6 Feb 2026
- Last updated
- 28 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Organ Procurement and Transplantation Network (OPTN) and Scientific Registry of Transplant Recipients (SRTR). OPTN/SRTR 2023 Annual Data Report. U.S. Department of Health and Human Services, Health Resources and Services Administration; 2025.
Yo JH, Fields N, Li W, Anderson A, Marshall SA, Kerr PG, Palmer KR. Adverse Pregnancy Outcomes in Solid Organ Transplant Recipients: A Systematic Review and Meta-Analysis. JAMA Netw Open. 2024 Aug 1;7(8):e2430913. doi: 10.1001/jamanetworkopen.2024.30913.
PubMed 39207751Rodrigues-Diez R, Gonzalez-Guerrero C, Ocana-Salceda C, Rodrigues-Diez RR, Egido J, Ortiz A, Ruiz-Ortega M, Ramos AM. Calcineurin inhibitors cyclosporine A and tacrolimus induce vascular inflammation and endothelial activation through TLR4 signaling. Sci Rep. 2016 Jun 13;6:27915. doi: 10.1038/srep27915.
PubMed 27295076Naesens M, Kuypers DR, Sarwal M. Calcineurin inhibitor nephrotoxicity. Clin J Am Soc Nephrol. 2009 Feb;4(2):481-508. doi: 10.2215/CJN.04800908.
PubMed 19218475Zheng S, Easterling TR, Umans JG, Miodovnik M, Calamia JC, Thummel KE, Shen DD, Davis CL, Hebert MF. Pharmacokinetics of tacrolimus during pregnancy. Ther Drug Monit. 2012 Dec;34(6):660-70. doi: 10.1097/FTD.0b013e3182708edf.
PubMed 23007747Schagen MR, Ulu AN, Francke MI, van de Wetering J, van Buren MC, Schoenmakers S, Matic M, van Schaik RHN, Hesselink DA, de Winter BCM. Modelling changes in the pharmacokinetics of tacrolimus during pregnancy after kidney transplantation: A retrospective cohort study. Br J Clin Pharmacol. 2024 Jan;90(1):176-188. doi: 10.1111/bcp.15886. Epub 2023 Sep 4.
PubMed 37596793Versluis J, Bourgonje AR, Touw DJ, Meinderts JR, Prins JR, de Jong MFC, Mian P. Pharmacokinetics of Tacrolimus in Pregnant Solid-Organ Transplant Recipients: A Retrospective Study. J Clin Pharmacol. 2024 Apr;64(4):428-436. doi: 10.1002/jcph.2393. Epub 2024 Jan 4.
PubMed 38084781Brannstrom M. A decade of human uterus transplantation. Acta Obstet Gynecol Scand. 2025 Mar;104(3):434-436. doi: 10.1111/aogs.15080. Epub 2025 Feb 19. No abstract available.
PubMed 39968606Testa G, McKenna GJ, Gunby RT Jr, Anthony T, Koon EC, Warren AM, Putman JM, Zhang L, dePrisco G, Mitchell JM, Wallis K, Klintmalm GB, Olausson M, Johannesson L. First live birth after uterus transplantation in the United States. Am J Transplant. 2018 May;18(5):1270-1274. doi: 10.1111/ajt.14737. Epub 2018 Apr 12.
PubMed 29575738Wilson NK, Schulz P, Wall A, Parrott M, Testa G, Johannesson L, Sam T. Immunosuppression in Uterus Transplantation: Experience From the Dallas Uterus Transplant Study. Transplantation. 2023 Mar 1;107(3):729-736. doi: 10.1097/TP.0000000000004437. Epub 2023 Feb 21.
PubMed 36445981
Study at a glance
From the registry record, last updated by the sponsor on 28 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Optimization of Tacrolimus Management During Pregnancy: Modeling of Unbound and Whole Blood Tacrolimus in Pregnant Uterus Transplant Recipients
- ClinicalTrials.gov ID
- NCT07422012
- Acronym / sponsor ID
- 026-140
- Conditions
- Unbound Tacrolimus in Pregnant Uterus Transplant Recipients, Whole Blood Tacrolimus in Pregnant Uterus Transplant Recipients
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 55 participants (estimated)
- Lead sponsor
- Baylor Research InstituteUniversity, hospital or other
- Collaborators
- Children's Hospital Medical Center, Cincinnati, University of Washington
- Study start
- 31 May 2026 (estimated)
- Primary completion
- Feb 2028 (estimated)
- Study completion
- Mar 2028 (estimated)
- First posted
- 19 Feb 2026 (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.
To create a formula that adjusts tacrolimus blood levels. This is needed because pregnant patients have higher levels of unbound tacrolimus. The adjusted formula will give a more accurate measure of the active drug in pregnant uterus transplant patients.
Detailed description
A non-linear mixed effects model describing tacrolimus exposure in pregnant and non-pregnant subjects will be developed using prospectively collected de-identified data from pregnant uterus transplant recipients at BUMC.
The model will be analyzed to develop an estimating equation for tacrolimus unbound concentrations from whole blood concentrations, albumin and hematocrit during each trimester of pregnancy.
The estimating equation will then be applied to data from uterus transplant recipients enrolled in this study and retrospectively to uterus recipients transplanted since October 2020 to clinically validate the findings.
Study design
- Observational model
- Case only
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Pregnant Individuals | – | Biological: Modeling of unbound and whole blood tacrolimus in pregnant uterus transplant recipientsIndividuals who had a uterus transplant that are using tacrolimus during pregnancy. |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- Female only
- Age groups
- Adult
- Study population
- Uterus transplant recipient over 18 years of age receiving tacrolimus for immunosuppression.
Key inclusion criteria (3 listed)
- Uterus transplant recipient
- 18 to 50 years of age
- receiving tacrolimus for immunosuppression.
Key exclusion criteria (2 listed)
- Individuals who have not had a uterine transplant
- individuals over 50 years old
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 |
|---|---|---|
| Modeling of unbound and whole blood tacrolimus in pregnant uterus transplant recipientsDevelop an estimating equation to correct tacrolimus whole blood concentrations given the known increase in the unbound tacrolimus concentration in pregnant patients to obtain a more accurate picture of active tacrolimus exposure (unbound drug) in pregnant uterus transplant recipients. | Biological | Pregnant Individuals |
Primary outcome
Understanding Tacrolimus Levels in Pregnancy
Time frame: 2nd (weeks 13-26) and 3rd (weeks 27-40) trimester of pregnancy
Develop a joint non-linear mixed effect population pharmacokinetic model describing bound and unbound tacrolimus pharmacokinetics in pregnant subjects.
2 secondary outcomes
Adjusting Tacrolimus Blood Levels by Trimester
Time frame: 2nd (weeks 13-26) and 3rd (weeks 27-40) trimester of pregnancy
Linking the Mixed Pharmacokinetic Model and the Equation to Adjust Whold Blood Tacrolimus Concentrations to Active Tacrolimus Levels During and After Pregnancy
Time frame: 1 week postpartum, 4 weeks, 5 weeks and 6 weeks postpartum
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Apr 2026.
- BackgroundOrgan Procurement and Transplantation Network (OPTN) and Scientific Registry of Transplant Recipients (SRTR). OPTN/SRTR 2023 Annual Data Report. U.S. Department of Health and Human Services, Health Resources and Services Administration; 2025.
- Background: PubMed 39207751Yo JH, Fields N, Li W, Anderson A, Marshall SA, Kerr PG, Palmer KR. Adverse Pregnancy Outcomes in Solid Organ Transplant Recipients: A Systematic Review and Meta-Analysis. JAMA Netw Open. 2024 Aug 1;7(8):e2430913. doi: 10.1001/jamanetworkopen.2024.30913.
- Background: PubMed 27295076Rodrigues-Diez R, Gonzalez-Guerrero C, Ocana-Salceda C, Rodrigues-Diez RR, Egido J, Ortiz A, Ruiz-Ortega M, Ramos AM. Calcineurin inhibitors cyclosporine A and tacrolimus induce vascular inflammation and endothelial activation through TLR4 signaling. Sci Rep. 2016 Jun 13;6:27915. doi: 10.1038/srep27915.
- Background: PubMed 19218475Naesens M, Kuypers DR, Sarwal M. Calcineurin inhibitor nephrotoxicity. Clin J Am Soc Nephrol. 2009 Feb;4(2):481-508. doi: 10.2215/CJN.04800908.
- Background: PubMed 23007747Zheng S, Easterling TR, Umans JG, Miodovnik M, Calamia JC, Thummel KE, Shen DD, Davis CL, Hebert MF. Pharmacokinetics of tacrolimus during pregnancy. Ther Drug Monit. 2012 Dec;34(6):660-70. doi: 10.1097/FTD.0b013e3182708edf.
- Background: PubMed 37596793Schagen MR, Ulu AN, Francke MI, van de Wetering J, van Buren MC, Schoenmakers S, Matic M, van Schaik RHN, Hesselink DA, de Winter BCM. Modelling changes in the pharmacokinetics of tacrolimus during pregnancy after kidney transplantation: A retrospective cohort study. Br J Clin Pharmacol. 2024 Jan;90(1):176-188. doi: 10.1111/bcp.15886. Epub 2023 Sep 4.
- Background: PubMed 38084781Versluis J, Bourgonje AR, Touw DJ, Meinderts JR, Prins JR, de Jong MFC, Mian P. Pharmacokinetics of Tacrolimus in Pregnant Solid-Organ Transplant Recipients: A Retrospective Study. J Clin Pharmacol. 2024 Apr;64(4):428-436. doi: 10.1002/jcph.2393. Epub 2024 Jan 4.
- Background: PubMed 39968606Brannstrom M. A decade of human uterus transplantation. Acta Obstet Gynecol Scand. 2025 Mar;104(3):434-436. doi: 10.1111/aogs.15080. Epub 2025 Feb 19. No abstract available.
- Background: PubMed 29575738Testa G, McKenna GJ, Gunby RT Jr, Anthony T, Koon EC, Warren AM, Putman JM, Zhang L, dePrisco G, Mitchell JM, Wallis K, Klintmalm GB, Olausson M, Johannesson L. First live birth after uterus transplantation in the United States. Am J Transplant. 2018 May;18(5):1270-1274. doi: 10.1111/ajt.14737. Epub 2018 Apr 12.
- Background: PubMed 36445981Wilson NK, Schulz P, Wall A, Parrott M, Testa G, Johannesson L, Sam T. Immunosuppression in Uterus Transplantation: Experience From the Dallas Uterus Transplant Study. Transplantation. 2023 Mar 1;107(3):729-736. doi: 10.1097/TP.0000000000004437. Epub 2023 Feb 21.
- Individual participant dataSharing planned: No
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.
Nicole Wilson, Pharmacist principal investigator
Baylor Scott and White Health
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Unbound Tacrolimus in Pregnant Uterus Transplant Recipients and Whole Blood Tacrolimus in Pregnant Uterus Transplant Recipients, run by Baylor Research Institute 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 2 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: opening soon, as of the sponsor's last update on 28 Apr 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. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Ashley McAllister (214-820-1710, ashley.mcallister@bswhealth.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Understanding Tacrolimus Levels in Pregnancy (time frame: 2nd (weeks 13-26) and 3rd (weeks 27-40) trimester of pregnancy). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07422012, which also lists 10 linked publications.
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 28 Apr 2026.