Abatacept Rescue Therapy in Kidney Transplant Recipients: A Case Series of Five Patients

Costimulation blockade: the next generation

PURPOSE OF REVIEW

Calcineurin inhibitors (CNIs) are central to immunosuppression in kidney transplantation (KT), improving short-term outcomes but falling short in enhancing long-term outcomes due to cardiovascular, metabolic, and renal complications. Belatacept, an FDA-approved costimulation blocker, offers a less toxic alternative to CNIs but is limited by its intravenous administration and reduced efficacy in high-immunological-risk patients.

RECENT FINDINGS

Emerging therapies target more specific pathways to improve efficacy and accessibility. Abatacept, a first-generation cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) immunoglobulin, has shown favorable outcomes in small studies. VEL-101 and Lulizumab selectively block CD28 while preserving CTLA-4 signaling, showing promise in early trials. In the CD40/CD40L pathway, results have been mixed. Iscalimab (CD40 antibody) was inferior to tacrolimus in Phase 2 trials, and Bleselumab (CD40 antibody) showed variable rejection rates despite being noninferior to tacrolimus. CD40L-targeting agents such as TNX-1500, Tegoprubart, and Dazodalibep have demonstrated promising efficacy and safety in rejection prophylaxis.

SUMMARY

The focus in transplantation is shifting toward safer, long-term therapies with greater accessibility. Investigational agents with subcutaneous delivery methods could overcome logistical challenges, improve adherence, and redefine posttransplant care. These advancements in costimulation blockade may enhance long-term graft survival and transform the management of KT recipients.

New Developments and Therapeutic Drug Monitoring Options in Costimulatory Blockade in Solid Organ Transplantation: A Systematic Critical Review

PURPOSE

In this review, the authors summarized the latest developments in costimulatory blockade to prevent rejection after solid organ transplantation (SOT) and discussed possibilities for future research and the need for therapeutic drug monitoring (TDM) of these agents.

METHODS

Studies about costimulatory blockers in SOT in humans or animal transplant models in the past decade (2014-2024) were systematically reviewed in PubMed, European Union clinical trials (EudraCT), and ClinicalTrials.gov .

RESULTS

Seventy-five registered clinical trials and 58 published articles were found on costimulation blockade of the CD28-CD80/86, CD40-CD40L, and OX40-OX40L pathways. Belatacept, an antagonist of the CD28-CD80/86 pathway, is the only approved costimulatory agent in SOT, hence accounting for most of the research. Other identified costimulatory blocking agents included abatacept and CD28 antagonists tegoprubart, dazodalibep, and TNX-1500. Although tegoprubart was unsuccessful in pancreas transplantation in nonhuman primates, trials in human kidney transplantation are underway. Dazodalibep trials faced recruitment challenges. TNX-1500 was unsuccessful in animal studies and is currently not pursued in humans. After discontinuation of iscalimab (CD40-CD154 pathway antagonist) in SOT, the alternatives, bleselumab and KPL404, showed promising results in kidney transplantation and cardiac xenotransplantation. Studies on secondary costimulatory pathway antagonists, such as OX40-OX40L, have only used animal models. Despite the low interindividual variability in pharmacokinetics (PK) in all studied agents, TDM could be useful for optimizing dosing in PK/pharmacodynamic (PD) studies.

CONCLUSIONS

The routine use of costimulation blockade in SOT is hindered by problems in efficacy compared with the standard of care. Costimulatory inhibitors could be combined in a calcineurin inhibitor-free regimen. Future PK/pharmacodynamic studies in costimulatory agents and personalized medicine could warrant TDM of these agents.

Cationic nanoparticles-based approaches for immune tolerance induction in vivo

The development of autoimmune diseases and the rejection of transplanted organs are primarily caused by an exaggerated immune response to autoantigens or graft antigens. Achieving immune tolerance is crucial for the effective treatment of these conditions. However, traditional therapies often have limited therapeutic efficacy and can result in systemic toxic effects. The emergence of nanomedicine offers a promising avenue for addressing immune-related diseases. Among the various nanoparticle formulations, cationic nanoparticles have demonstrated significant potential in inducing immune tolerance. In this review, we provide an overview of the underlying mechanism of autoimmune disease and organ transplantation rejection. We then highlight the recent advancements and advantages of utilizing cationic nanoparticles for inducing immune tolerance in the treatment of autoimmune diseases and the prevention of transplant rejection.

Costimulatory Blockade and Solid Organ Transplantation: The Past, Present, and Future

Belatacept is the first costimulatory blockade agent clinically approved for transplant immunosuppression. Although more than 10 years of study have demonstrated that belatacept offers superior long-term renal allograft and patient survival compared to conventional calcineurin inhibitor (CNI)-based immunosuppression regimens, the clinical adoption of belatacept has continued to lag because of concerns of an early risk of acute cellular rejection (ACR) and various logistical barriers to its administration. In this review, the history of the clinical development of belatacept is examined, along with the findings of the seminal BENEFIT and BENEFIT-EXT trials culminating in the clinical approval of belatacept. Recent efforts to incorporate belatacept into novel CNI-free immunosuppression regimens are reviewed, as well as the experience of the Emory Transplant Center in using a tapered course of low-dose tacrolimus in belatacept-treated renal allograft patients to garner the long-term outcome benefits of belatacept without the short-term increased risks of ACR. Potential avenues to increase the clinical adoption of belatacept in the future are explored, including surmounting the logistical barriers of belatacept administration through subcutaneous administration or more infrequent belatacept dosing. In addition, belatacept conversion strategies and potential expanded clinical indications of belatacept are discussed for pediatric transplant recipients, extrarenal transplant recipients, treatment of antibody-mediated rejection (AMR), and in patients with failed renal allografts. Finally, we discuss the novel immunosuppressive drugs currently in the development pipeline that may aid in the expansion of costimulation blockade utilization.

Safe and Efficient Use of Tocilizumab in Rheumatoid Arthritis Patient on Maintenance Hemodialysis: A Case Report

Background: Rheumatoid arthritis (RA) is a chronic systemic autoimmune and inflammatory disease. Conventional synthetic and biologic disease-modifying antirheumatic drugs (DMARDs), Janus kinase inhibitors, and rituximab are used to treat the disease. There are no recommendations or guidelines for the treatment of patients with both inflammatory arthritis and end-stage renal disease (ESRD), despite the safety and efficacy of the mentioned drugs. The anti-interleukin-6 receptor antibody tocilizumab (TCZ) has not been used as a long-term therapy for hemodialysis (HD) patients with RA, except in a few case reports. Case Description: We present the case of a 41-year-old patient with RA and ESRD on maintenance HD due to type 1 diabetes-related complications. Due to high RA disease activity, the patient was not a suitable candidate for a kidney transplant. Because TCZ is used to treat both RA and kidney transplant rejection, therapy with a full dose of TCZ was administered. The patient has achieved sustained clinical remission (for the past four years) with no adverse events reported. Conclusions: Herein, we present the safe and effective use of TCZ in an RA patient on HD who is also a candidate for kidney transplant. Consequently, TCZ could be the treatment of choice for RA patients with ESRD who have not achieved disease control (low activity or remission) with conventional synthetic DMARDs. Clinical studies are required to evaluate the efficacy and safety of biologic DMARDs and Janus kinase inhibitors in patients with both inflammatory arthritis and ESRD.

Conversion From Intravenous In-Hospital Belatacept Injection to Subcutaneous Abatacept Injection in Kidney Transplant Recipients During the First COVID-19 Stay-at-Home Order in France

The first COVID-19 stay-at-home order came into effect in France on 17 March 2020. Immunocompromised patients were asked to isolate themselves, and outpatient clinic visits were dramatically reduced. In order to avoid visits to the hospital by belatacept-treated kidney transplant recipients (KTRs) during the initial period of the pandemic, we promptly converted 176 KTRs at two French transplant centers from once-monthly 5 mg/kg in-hospital belatacept infusion to once-weekly 125 mg subcutaneous abatacept injection. At the end of follow-up (3 months), 171 (97.16%) KTRs survived with a functioning graft, 2 (1.14%) had died, and 3 (1.70%) had experienced graft loss. Two patients (1.1%) experienced acute T cell-mediated rejection. Nineteen patients (10.80%) discontinued abatacept; 47% of the KTRs found the use of abatacept less restrictive than belatacept, and 38% would have preferred to continue abatacept. Mean eGFR remained stable compared to baseline. Seven patients (3.9%) had COVID-19; among these, two developed severe symptoms but survived. Only one patient had a de novo DSA. Side effects of abatacept injection were uncommon and non-severe. Our study reports for the first time in a large cohort that once-weekly injection of abatacept appears to be feasible and safe in KTRs previously treated with belatacept.