Belatacept for the prophylaxis of organ rejection in kidney transplant patients: an evidence-based review of its place in therapy

Drug delivery strategies for local immunomodulation in transplantation: Bridging the translational gap

Drug delivery strategies for local immunomodulation hold tremendous promise compared to current clinical gold-standard systemic immunosuppression as they could improve the benefit to risk ratio of life-saving or life-enhancing transplants. Such strategies have facilitated prolonged graft survival in animal models at lower drug doses while minimizing off-target effects. Despite the promising outcomes in preclinical animal studies, progression of these strategies to clinical trials has faced challenges. A comprehensive understanding of the translational barriers is a critical first step towards clinical validation of effective immunomodulatory drug delivery protocols proven for safety and tolerability in pre-clinical animal models. This review overviews the current state-of-the-art in local immunomodulatory strategies for transplantation and outlines the key challenges hindering their clinical translation.

Basiliximab as maintenance immunosuppression in heart transplant recipients: A single pediatric center experience

BACKGROUND

Pediatric heart transplant recipients are at risk for complications from prolonged exposure to immunosuppressive drugs, pharmacokinetic challenges in maintaining consistent immunosuppression, and medication non-adherence. Basiliximab (BAS), an interleukin-2 receptor antagonist, is used for induction therapy across many pediatric heart transplant centers, but use as maintenance immunosuppression has not been well described.

METHODS

This was a retrospective, single pediatric center cohort study of heart transplant recipients who received BAS for maintenance immunosuppression (defined as >2 monthly doses) from January 1, 2011, to December 31, 2021.

RESULTS

Ten patients met study criteria with a median age of 17.5 (5-22) years and median 9.6 (1.2-18.9) years since transplant at time of BAS initiation. The primary indications for BAS use were recurrent rejection (n = 4), fluctuating immunosuppression levels (n = 3), and renal dysfunction (n = 3). A median of 5.5 (3-32) monthly BAS doses were received. Three patients had a rejection event while on BAS. Calcineurin inhibitor exposure was reduced in 70% of patients. Three of the 10 patients were alive at last follow-up. There was one documented infection during BAS use, and no hypersensitivity reactions.

CONCLUSIONS

Monthly BAS infusions were well tolerated and allowed for reduced calcineurin inhibitor exposure in most patients. Mortality commonly occurred despite BAS use, potentially reflecting the acuity of this patient cohort. BAS can be considered for maintenance immunosuppression in pediatric patients with fluctuating immunosuppressive levels and/or renal dysfunction. More studies are needed to determine long-term outcomes and explore expanded use of BAS in the pediatric heart transplant population.

Conversion to Belatacept in kidney transplant recipients with chronic antibody-mediated rejection (CAMR)

BACKGROUND

The costimulatory inhibitor Belatacept (Bela) has been shown to be an effective alternative in several clinical situations, including chronic antibody-mediated rejection, calcineurin toxicity, and de novo alloantibody formation. To further explore the usefulness of Belatacept under various clinical scenarios, we performed a retrospective analysis of a prospective database of all recipients who had a BPAR diagnosis of CAMR and were converted to a Belatacept maintenance immunosuppression regimen after kidney transplantation.

MATERIAL AND METHOD

We conducted a retrospective analysis of a prospectively collected database of all kidney transplants adult patients at SUNY Upstate Medical Hospital from 1 January 2013 to 31 December 2021. Our inclusion criteria were the patients who have been diagnosed with CAMR according to their renal biopsy based on the 2013 Banff criteria. The primary objective was to compare the kidney viability and function using GFR between the two interest groups and finally compare the outcomes.

RESULTS

A total of 48 patients met our inclusion criteria based on the kidney biopsy result, which showed chronic antibody-mediated graft rejection (CAMR). Nineteen patients (39.6%) were converted to the Belatacept, and we continued the previous immunosuppression regimen in 29 patients (60.4%). The mean time from the transplant date to the diagnosis of CAMR was 1385 days in the Belatacept group and 914 days for the non-Belatacept group (P = 0.15). The mean GFR comparison at each time point between the groups did not show a significant difference, and Belatacept did not show superiority compared to the standard immunosuppression regimen in terms of kidney function preservation. 1 (5.2%) patient from the Belatacept group and 1 (3.4%) patient from the non-Belatacept group had a biopsy-proven acute rejection (BPAR) after CAMR confirmation, and it was comparable (P = 0.76). De novo synthesis of the DSA rate was 12.5% in the Belatacept group and 15% In the non-Belatacept group, which was comparable. (P = 0.90). The patient survival rate was 100% in both groups.

CONCLUSIONS

We conclude that compared to the standard Tacrolimus/MMF/Prednisone regimen, Belatacept did not significantly benefit in preserving the GFR in long-term follow-ups and stabilizing the DSA production, which is one of the main factors resulting in chronic graft failure.

Emerging local immunomodulatory strategies to circumvent systemic immunosuppression in cell transplantation

INTRODUCTION

Cell transplantation is a promising curative therapeutic strategy whereby impaired organ functions can be restored without the need for whole organ transplantation. A key challenge in allotransplantation is the requirement for life-long systemic immunosuppression to prevent rejection, which is associated with serious adverse effects such as increased risk of opportunistic infections and the development of neoplasms. This challenge underscores the urgent need for novel strategies to prevent graft rejection while abrogating toxicity-associated adverse events.

AREAS COVERED

We review recent advances in immunoengineering strategies for localized immunomodulation that aim to support allograft function and provide immune tolerance in a safe and effective manner.

EXPERT OPINION

Immunoengineering strategies are tailored approaches for achieving immunomodulation of the transplant microenvironment. Biomaterials can be adapted for localized and controlled release of immunomodulatory agents, decreasing the effective dose threshold and frequency of administration. The future of transplant rejection management lies in the shift from systemic to local immunomodulation with suppression of effector and activation of regulatory T cells, to promote immune tolerance.

Belatacept in Solid Organ Transplant: Review of Current Literature Across Transplant Types

Calcineurin inhibitors (CNIs) have been the backbone immunosuppressant for solid organ transplant recipients for decades. Long-term use of CNIs unfortunately is associated with multiple toxicities, with the biggest concern being CNI-induced nephrotoxicity. Belatacept is a novel agent approved for maintenance immunosuppression in renal transplant recipients. In the kidney transplant literature, it has shown promise as being an alternative agent by preserving renal function and having a minimal adverse effect profile. There are emerging studies of its use in other organ groups, particularly liver transplantation, as well as using with other alternative immunosuppressive strategies. The purpose of this review is to analyze the current literature of belatacept use in solid organ transplantation and discuss its use in current practice.