Tacrolimus in Pregnancy

NCT07422012 | Not Yet Recruiting

• 1 other identifier: 026-140
• Study Type: observational
• Target: 55
• Locations: 1 country
• Sites: 1

Brief 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.

Conditions

Unbound Tacrolimus in Pregnant Uterus Transplant Recipients; Whole Blood Tacrolimus in Pregnant Uterus Transplant Recipients

Outcome Measures

Primary Outcomes (1)

• Understanding Tacrolimus Levels in Pregnancy

  Develop a joint non-linear mixed effect population pharmacokinetic model describing bound and unbound tacrolimus pharmacokinetics in pregnant subjects.

  2nd (weeks 13-26) and 3rd (weeks 27-40) trimester of pregnancy

Secondary Outcomes (2)

• Adjusting Tacrolimus Blood Levels by Trimester

  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

  1 week postpartum, 4 weeks, 5 weeks and 6 weeks postpartum

Study Arms (1)

Pregnant Individuals

Individuals who had a uterus transplant that are using tacrolimus during pregnancy.

Biological: Modeling of unbound and whole blood tacrolimus in pregnant uterus transplant recipients

Interventions

Modeling of unbound and whole blood tacrolimus in pregnant uterus transplant recipients BIOLOGICAL

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.

Pregnant Individuals

Eligibility Criteria

• Age: 18 Years - 50 Years
• Gender Eligibility Details: biologically born women
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

Uterus transplant recipient over 18 years of age receiving tacrolimus for immunosuppression.

You may qualify if:

• Uterus transplant recipient
• to 50 years of age
• receiving tacrolimus for immunosuppression.

You may not qualify if:

• Individuals who have not had a uterine transplant
• individuals over 50 years old

Sponsors & Collaborators

• Baylor Research Institute: lead
• Children's Hospital Medical Center, Cincinnati: collaborator
• University of Washington: collaborator

Study Sites (1)

Baylor University Center of Dallas

Dallas, Texas, 75246, United States

Location

Related Publications (10)

• 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.

  BACKGROUND

• Yo JH, Fields N, Li W, et al. Adverse Pregnancy Outcomes in Solid Organ Transplant Recipients: A Systematic Review and Meta-Analysis. JAMA Netw Open. 2024;7(8):e2430913.

  BACKGROUND

• Rodrigues-Diez R, González-Guerrero C, Ocaña-Salceda C, et al. Calcineurin inhibitors cyclosporine A and tacrolimus induce vascular inflammation and endothelial activation through TLR4 signaling. Sci Rep. 2016;6:27915.

  BACKGROUND

• Naesens M, Kuypers DRJ, Sarwal M. Calcineurin inhibitor nephrotoxicity. Clin J Am Soc Nephrol. 2009;4(2):481-508.

  BACKGROUND

• Zheng S, Easterling TR, Umans JG, et al. Pharmacokinetics of tacrolimus during pregnancy. Ther Drug Monit. 2012;34(6):660-670.

  BACKGROUND

• Schagen MR, Ulu AN, Francke MI, et al. Modelling changes in the pharmacokinetics of tacrolimus during pregnancy after kidney transplantation: A retrospective cohort study. Br J Clin Pharmacol. 2024;90(1):176-188.

  BACKGROUND

• Versluis J, Bourgonje AR, Touw DJ, et al. Pharmacokinetics of tacrolimus in pregnant solid-organ transplant recipients: a retrospective study. The Journal of Clinical Pharma. 2024;64(4):428-436.

  BACKGROUND

• Brännström M. A decade of human uterus transplantation. Acta Obstet Gynecol Scand. 2025;104(3):434-436.

  BACKGROUND

• Testa, G., McKenna, G. J., Gunby Jr, R. T., Anthony, T., Koon, E. C., Warren, A. M., Johannesson, L. (2018). First live birth after uterus transplantation in the United States. American Journal of Transplantation, 18(5), 1270-1274.

  BACKGROUND

• Wilson NK, Schulz P, Wall A, et al. Immunosuppression in uterus transplantation: experience from the dallas uterus transplant study. Transplantation. 2023;107(3):729-736.

  BACKGROUND

Biospecimen

Retention: SAMPLES WITH DNA

Blood

Study Officials

• Nicole Wilson, Pharmacist

  Baylor Scott and White Health

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Ashley McAllister

CONTACT

214-820-1710; ashley.mcallister@bswhealth.org

Taryn Kruse

CONTACT

214-820-1767; taryn.kruse@bswhealth.org

Study Design

• Study Type: observational
• Observational Model: CASE ONLY
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: February 6, 2026
• First Posted: February 19, 2026
• Study Start: May 31, 2026
• Primary Completion (Estimated): February 1, 2028
• Study Completion (Estimated): March 1, 2028
• Last Updated: April 28, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)