NCT05975450: RTB-016

Subcutaneous Abatacept in Renal Transplant Recipients

Completed Phase 1 Results posted Last updated 3 April 2026

What this trial tests

Phase 1 trial testing Abatacept 125Mg/Ml Syringe in Kidney Transplant Recipient in 16 participants. Completed in 14 February 2025.

Timeline

2 August 2023

Primary endpoint
14 February 2025

14 February 2025

Quick facts

Lead sponsor	Idelberto Badell
Phase	Phase 1
Status	Completed
Study type	INTERVENTIONAL
Allocation	na
Design	single group
Masking	none
Primary purpose	treatment
Enrollment	16
Start date	2 August 2023
Primary completion	14 February 2025
Estimated completion	14 February 2025
Sites	2 locations across United States

Drugs / interventions tested

• Abatacept 125Mg/Ml Syringe — full drug profile →

Conditions studied

• Kidney Transplant Recipient — all drugs for Kidney Transplant Recipient →

Sponsor

Idelberto Badell — full company profile →

Who can join

Adults 18 to 70, any sex, with Kidney Transplant Recipient. Patients with the condition only — healthy volunteers not accepted.

Results — posted to ClinicalTrials.gov

Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.

Number of Participants Who Are Compliant With Self-administration Primary · Up to 12 months post-transplantation, an average of 8 months

Compliance and self-administration will be measured using the abatacept administration logs and autoinjector accountability.

Group	Value	95% CI
Abatacept	8
Abatacept	5
Abatacept	1

Number of Participants Who Remain Free of Biopsy-proven Acute T-cell Mediated Rejection (aTCMR) or Antibody-mediated Rejection (ABMR) as Defined by Banff Criteria at or Before 12 Months After Transplantation. Primary · Up to 12 months post-transplantation, an average of 8 months

For-cause biopsies may be performed as dictated by the clinical team. A for-cause biopsy (i.e., graft dysfunction) may be performed in cases of increased serum creatinine, proteinuria, or other clinical symptoms at the discretion of the site Investigator.

Group	Value	95% CI
Abatacept	13

Number of Participants Presenting Serious Adverse Events Primary · Up to 12 months post-transplantation, an average of 8 months

Assessments of serious adverse events will be completed at each study visit from the time abatacept starts through 12 months post-transplant.

Group	Value	95% CI
Abatacept	1

Number of Participants With Serious Infections Primary · Up to 12 months post-transplantation, an average of 8 months

Any serious infection requiring hospitalization or prolonged therapy, including but not limited to treatment ≥ 20 days, will be documented.

Group	Value	95% CI
Abatacept	0

Number of Patients With Cytomegalovirus (CMV) Viremia Stratified by the Magnitude Primary · Up to 12 months post-transplantation, an average of 8 months

All subjects will be monitored for CMV infection by quantitative polymerase chain reaction (PCR) in the blood per the Emory Transplant Center standard of care protocol, CMV viremia stratified by count ≥35 but \<10,000 or ≥ 10,000.

≥35 but <10,000

Group	Value	95% CI
Abatacept	1

≥ 10,000

Group	Value	95% CI
Abatacept	1

Number of Patients With BK Viremia Stratified by the Magnitude Primary · Up to 12 months post-transplantation, an average of 8 months

Undetected, \>0 but \< 1,000, ≥ 1,000 but \<10,000, or ≥ 10,000 - 100,000, ≥100,000 or stratified by log, which is reported as a result.

Group	Value	95% CI
Abatacept	13
Abatacept	0
Abatacept	1
Abatacept	0

Number of Participants Who Develop Any Malignancy Primary · Up to 12 months post-transplantation, an average of 8 months

Incidence of any malignancy, including Post-Transplant Lymphoproliferative Disorder (PTLD)

Group	Value	95% CI
Abatacept	0

Number of Participants Experiencing the Composite Outcome of Death or Allograft Failure Secondary · Up to 12 months post-transplantation, an average of 8 months

Death and/or allograft failure at or before 12 months after transplantation

Group	Value	95% CI
Abatacept	0

Number of Participants With Biopsy-proven Acute T-cell Mediated Cellular Rejection (BP-aTCMR) Secondary · Up to 12 months post-transplantation, an average of 8 months

Incidence of biopsy-proven acute T-cell mediated cellular rejection (BP-aTCMR)

Group	Value	95% CI
Abatacept	1

Number of Participants Treated for Rejection Secondary · Up to 12 months post-transplantation, an average of 8 months

The number of participants treated for rejection with any of the following: i) corticosteroids within 12 months, ii) T-cell depleting therapy within 12 months, iii) any other treatment for rejection within 12 months of transplantation

Group	Value	95% CI
Abatacept	1

Number of Participants Treated for Acute Rejection Due to Clinical Suspicion Rather Than BP-aTCMR or BP-aABMR Within 12 Months of Transplantation. Secondary · Up to 12 months post-transplantation, an average of 8 months

For-cause biopsies may be performed as dictated by the clinical team. A for-cause biopsy (i.e., graft dysfunction) may be performed in cases of increased serum creatinine, proteinuria, or other clinical symptoms at the discretion of the site Investigator.

Group	Value	95% CI
Abatacept	1

Number of Participants With Biopsy-proven Active Antibody-mediated Rejection (BP-aABMR) Secondary · Up to 12 months post-transplantation, an average of 8 months

For-cause biopsies may be performed as dictated by the clinical team. A for-cause biopsy (i.e., graft dysfunction) may be performed in cases of increased serum creatinine, proteinuria, or other clinical symptoms at the discretion of the site Investigator.

Group	Value	95% CI
Abatacept	1

Adverse events — posted to ClinicalTrials.gov

Time frame: Information on adverse events was collected from all participants throughout the study intervention and up to 12 months post-transplant, with an average of 8 months.. Reporting threshold: 0%. Adverse-event reports describe events observed during the trial — not all are caused by the drug.

Abatacept

Serious: 1/14 (7%)

Deaths: 0/14

Serious adverse events (1 terms)

Reaction	System	Abatacept
Acute Rejection	Blood and lymphatic system disorders	—

Other adverse events (8 terms — click to expand)

Reaction	System	Abatacept
Irritability	General disorders	—
Hematospermia	Reproductive system and breast disorders	—
Atrial Fibrillation	Cardiac disorders	—
Increased creatinine	Investigations	—
Possible Class II Donor-Specific Antibodies (DSA)	Immune system disorders	—
Acute kidney injury (AKI)	Renal and urinary disorders	—
Low white blood cell (WBC) count	Investigations	—
Viremia	Infections and infestations	—

Most-reported serious reactions: Acute Rejection.

Data from ClinicalTrials.gov NCT05975450 adverse events section.

Sponsor's own description

After a kidney transplant, patients take drugs called anti-rejection drugs (immunosuppressives) to prevent their bodies from rejecting the new kidney. At present it is not possible to have a successful transplant without these drugs. These drugs make it possible for a person who receives the transplant to accept the "foreign" kidney. Most patients who get a transplant need to take anti-rejection medications for the rest of their lives, or for as long as the kidney continues to work.

Researchers are looking to learn whether abatacept is as good as belatacept in preventing rejection, whether there are other benefits or harms associated with abatacept treatment, and possibly allows greater flexibility on patient's travel and time since abatacept is self-administered at home.

This study is being done to answer these questions:

Are weekly abatacept injections under the skin a safe and effective substitute for monthly belatacept intravenous (IV) infusions? and How well does the kidney function after switching from belatacept to abatacept?

Publications & conference data

1 peer-reviewed publication reference this trial (live from Europe PMC):

1. Belatacept and regulatory T cells in transplantation: synergistic strategies for immune tolerance and graft survival.
   Kim GR, Nam KH, Choi JM. · · 2024 · PMID 39690903 · DOI 10.4285/ctr.24.0057