BESTOW: Tegoprubart Showcases Safer Prevention of Kidney Transplant Rejection Over Tacrolimus

Tegoprubart was well-tolerated in people receiving kidney transplant, with similar improvements in estimated glomerular filtration rate (eGFR) seen compared to those receiving tacrolimus.1

These findings, from the phase 2 BESTOW trial, were presented at the American Society of Nephrology (ASN) Kidney Week 2025, held November 5-9, 2025, in Houston, Texas, by Andrew B. Adams, MD, PhD, Professor and Chief, Division of Transplantation, and John S Najarian Surgical Chair in Clinical Transplantation, University of Minnesota Medical School, and Executive Medical Director, Solid Organ Transplant Service Line M Health Fairview.

“There remains a significant unmet need for safer alternatives to traditional tacrolimus-based immunosuppression regimens—options that can reduce harmful side effects without compromising efficacy. The Phase 2 results presented at ASN Kidney Week highlight the potential of tegoprubart to deliver strong graft function after kidney transplantation, while avoiding the long-term toxicities often associated with current standard of care,” Andrew Adams, MD, PhD, Professor of Surgery and Chief, Division of Transplantation, John S. Najarian Surgical Chair in Clinical Transplantation, Department of Surgery, University of Minnesota, said in a statement.2 “It’s been more than a decade since we’ve seen true innovation in transplant immunosuppression. These data offer real hope that patients may soon have a transformative therapy that improves their health outcomes and overall quality of life.”

BESTOW was a 12-month, randomized, head-to-head, Phase 2 trial evaluating 126 kidney transplant recipients receiving either tegoprubart (n = 63) or tacrolimus (n = 64) across 44 global sites. All patients also received rabbit antithymocyte globulin (rATG) induction and maintenance therapy with mycophenolate mofetil (MMF/MPA) and corticosteroids. The study primarily evaluated the change in eGFR at 12 months post-transplant. Also assessed were biopsy-proven acute rejection (BPAR), patient and graft survival, composite efficacy failure, iBox score, donor-specific antibodies (DSAs), delayed graft function (DGF), and new-onset diabetes after transplantation (NODAT).1

The trial did not meet its primary end point, with participants on tegoprubart reaching an eGFR of 69 mL/min/1.73 m² (n=51) at 12 months compared with 66 mL/min/1.73 m² for tacrolimus (n=56). However, nearly all tegoprubart subgroups demonstrated higher eGFRs than tacrolimus, with living-related donor recipients (~72 mL/min/1.73 m² vs. 62 mL/min/1.73 m²) and high Kidney Donor Profile Index (KDPI > 35) transplants (~62 mL/min/1.73 m² vs. 53 mL/min/1.73 m²) having particularly strong responses. In the deceased donor subgroup, participants on tegoprubart achieved a mean eGFR of approximately 68 mL/min/1.73 m² at 12 months.1

The tegoprubart group achieved the efficacy failure composite endpoint (comprising death, graft loss and biopsy proven acute rejection) at a rate of 22% compared to 17% in the tacrolimus group, demonstrating noninferiority. In its statement, Eledon asserted that these results support tegoprubart’s approvability.

Importantly, Adams and colleagues found that patients generally experienced a more favorable safety profile with tegoprubart over tacrolimus. Approximately 1 in 6 patients receiving tacrolimus developed new-onset diabetes versus 1 in 47 receiving tegoprubart, 25.0% of the tacrolimus group had tremor compared with 1.6% of the tegoprubart group, 15.9% had hypertension compared with 25.0%, 1,6% had hypertensive crisis compared with 7.8%, and 0% had heart failure compared with 4.7%.1

Notably, less participants on tegoprubart experienced delayed graft function (14.3%) and participants required shorter dialysis (4.6 days) compared to those on tacrolimus (25.0% and 6.1 days, respectively. These figures correlate to a potential reduction of 115 days on dialysis post-transplant per 100 deceased donor kidney recipients with tegoprubart compared with tacrolimus.1

Furthermore, sepsis or bacteremia occurred more frequently in the tacrolimus arm (17.2% vs. 4.8%) while rates of viral infections (CMV, BK, EBV, fungal) were similar across groups. There were no cases of Post-Transplant Lymphoproliferative Disorder (PTLD) or Progressive Multifocal Leukoencephalopathy (PML) and the overall rates of serious adverse events were comparable between treatment arms.1

The investigators also found that the rate of acute rejection in all biopsies was 20.6% in the tegoprubart group compared with 14.1% in the tacrolimus group. Among those in the tegoprubart group who experienced acute rejection and remained on treatment through month 12, mean eGFR was 73 mL/min/1.73 m², compared with 50 mL/min/1.73 m² in those who switched to tacrolimus. Donor-specific antibody cases emerged in 1 participant in the tegoprubart arm compared with 2 in the tacrolimus arm.1

“The Phase 2 BESTOW data results demonstrate tegoprubart’s potential to maintain excellent kidney function while reducing the chronic metabolic, neurologic, and cardiovascular toxicities that burden patients on tacrolimus,” David-Alexandre C. Gros, MD, Chief Executive Officer of Eledon, added.2 “By pairing strong immunosuppressive efficacy with a differentiated safety profile, including dramatically lower rates of new-onset diabetes, tremor, and dialysis-requiring delayed graft function, tegoprubart represents a promising next-generation option for kidney transplant immunosuppression as we advance into Phase 3.”

References

1. Adams AB, Tedesco-Silva H, Potter S, et al. Efficacy and Safety of Tegoprubart for the Prevention of Rejection in Kidney Transplantation: Results from the Phase 2 BESTOW Trial. Presented at: Presented at: ASN Kidney Week. Houston, Texas. November 05-09, 2025. # TH-OR089

2. Eledon Presents Phase 2 BESTOW Trial Results for Tegoprubart for the Prevention of Rejection in Kidney Transplantation at the American Society of Nephrology’s Kidney Week 2025 Annual Meeting. News release. Eledon Pharmaceuticals. November 6, 2025. https://www.globenewswire.com/news-release/2025/11/06/3183316/0/en/Eledon-Presents-Phase-2-BESTOW-Trial-Results-for-Tegoprubart-for-the-Prevention-of-Rejection-in-Kidney-Transplantation-at-the-American-Society-of-Nephrology-s-Kidney-Week-2025-Annu.html