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Thymosin-α1 for Recurrent Implantation Failure

Thymosin-α1 for Recurrent Implantation Failure Following Transfer of PGT-a Tested Embryo: A Randomized, Double-Blind, Placebo-Controlled Trial

Status
Recruiting
Phases
Phase 2Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07675980
Acronym
Thy-α1 for RIF
Enrollment
136
Registered
2026-06-30
Start date
2026-02-11
Completion date
2027-06-01
Last updated
2026-06-30

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Recurrent Implantation Faliure

Keywords

Thymosin, recurrent implantation failure, Thymosin alpha, PGT-a tested embryos

Brief summary

Clinical trial evaluating the safety and efficacy of Thymosin-α1 (Tα1) as an adjunctive immunomodulatory therapy in women with unexplained recurrent implantation failure (RIF) undergoing IVF/ICSI cycles.

Detailed description

Despite significant advancements in assisted reproductive technologies (ART), recurrent implantation failure (RIF) remains a persistent challenge. Growing evidence implicates dysregulation of both local endometrial and systemic immune components in the pathophysiology of RIF. This has led to increasing attention on immune dysregulation, including aberrant cytokine signaling, altered Th1/Th2 balance, heightened NK cell cytotoxicity, and impaired maternal-fetal tolerance as possible contributors. These immunological pathways are critical for embryo implantation and pregnancy continuation; their disruption can create an environment hostile to the developing conceptus. Thymosin-α1 (Tα1) is a naturally occurring thymic peptide with immune-modulatory properties. It has been historically used in the management of chronic viral infections and certain cancers, where it demonstrated the ability to enhance T-cell function, rebalance cytokine networks, and improve immune resilience. Its safety profile in non-obstetric conditions is well established. Although comprehensive safety evaluation of thymosin alpha in pregnant women has not yet been completed, emerging evidence from observational studies, case reports, and proposed clinical trials suggests that thymosin alpha is generally regarded as safe during pregnancy, with no reported adverse effects linked to its use to date. Specifically, a published case report documented successful pregnancy following thymosin alpha administration in a woman with recurrent implantation failure, noting an absence of fetal anomalies or significant adverse events and emphasizing the need for further prospective trials to establish broader safety and efficacy. Preliminary clinical protocols continue to monitor for adverse events in patients undergoing reproductive treatments, and none have identified safety concerns thus far. Emerging reproductive data suggest a potential role of Tα1 in implantation and pregnancy maintenance. Observational work reported lower maternal Tα1 levels in women whose pregnancies ended in miscarriage compared with those that continued to viability; this effect was not seen with thymosin-β4, suggesting specificity. Mechanistically, Tα1 enhances T-cell maturation, restores Th1/Th2 balance, and promotes regulatory T-cell activity-processes central to maternal immune tolerance during early pregnancy. Taken together, these findings highlight a gap: Tα1 has biological plausibility and early signals but no definitive RCT evidence. This underlines the need for a rigorous, placebo-controlled study of Tα1 in women with RIF. To our knowledge, this is the first randomized placebo-controlled study looking at Tα1 in RIF patients undergoing treatment using PGT-a tested embryos.

Interventions

Start at luteal start in ART cycles and continue until 10+6 weeks' gestation.

OTHERPlacebo Control

Matching placebo injections on the same schedule and duration.

Sponsors

Fakih IVF Fertility Center
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Masking description

This is double blind randomized controlled trial

Intervention model description

Thymosin alpha will be started during luteal phase of frozen embryo transfer cycle and continued till 12 weeks of pregnancy.

Eligibility

Sex/Gender
FEMALE
Age
18 Years to 40 Years
Healthy volunteers
No

Inclusion criteria

1. -Women 18-40 years 2. -RIF- ≥2 failed embryo transfers with PGT-a tested euploid embryos 3. \- Normal parental karyotypes 4. \- Normal uterine cavity on imaging 5. \- Negative antiphospholipid panel 6. \- Thyroid and prolactin controlled within local reference standards

Exclusion criteria

1. Identified/correctable non-immune cause of RPL (chromosomal, anatomic, endocrine) 2. \- Active malignancy 3. -Active infection 4. \- Uncontrolled systemic disease 5. \- Current systemic immunosuppression

Design outcomes

Primary

MeasureTime frameDescription
Live birth more than 24 weeksApproximately 40 weeksFrom date of randomization (luteal start ART) until end of intervention at 10 + 6 weeks and assessed up to live birth or miscarriage. Approximately 40 weeks.
Determine whether Tα1 increases live birth versus placebo.Approximately 40 weeksLive birth (singleton or multiple)

Countries

United Arab Emirates

Contacts

CONTACTDr. Lamiya Mohiyiddeen, MD, FRCOG
lamiya.mohiyiddeen@fakihivf.com+971543676002
CONTACTFatma Bathawab, PhD
fatma.bathawab@fakihivf.com+971585707393
PRINCIPAL_INVESTIGATORMichael Fakih, MD

Fakih IVF Abu Dhabi

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jul 1, 2026