A recent clinical trial reveals that an experimental, calcineurin-inhibitor-free immunosuppressant drug, tegoprubart, significantly outperforms the current standard-of-care treatment for preventing kidney transplant rejection.
Developed by Eledon Pharmaceuticals, tegoprubart is a specialized anti-CD40L antibody that selectively blocks the activation of specific immune cells in the CD40L pathway. This offers a highly precise target compared to tacrolimus—the traditional standard therapy used since the 1990s—which broadly suppresses the entire immune system and carries direct nephrotoxicity (kidney toxicity).
Long-term extension data from the Phase 2 BESTOW trial (Adams, 2025) was presented at the recent 2026 American Transplant Congress in Boston by study leader Dr. Andrew Adams, Professor of Surgery and Chief of the Division of Transplantation at the University of Minnesota.
The updated results highlight the drug’s clear clinical superiority:
Zero Late Rejection: Patients taking tegoprubart experienced no graft loss and zero biopsy-proven acute rejection (BPAR) episodes after the first six months post-transplant. In contrast, the tacrolimus group experienced ongoing rejections, with roughly 64% of their total rejection events occurring after the six-month mark.
Superior Organ Function: Tegoprubart patients maintained significantly higher kidney function over time, showing a statistically significant 12 mL/min/1.73 m² advantage in mean estimated glomerular filtration rate (eGFR) at month 18 compared to the tacrolimus group (74 vs. 61 mL/min/1.73 m²).
Fewer Side Effects: Only 2% of tegoprubart patients experienced headaches or acute kidney injury, compared to 12% and 6% for tacrolimus. Standard-of-care patients also suffered from extremity pain (10%), diarrhea (21%), and balance loss (6%), which were minimal or entirely absent in the tegoprubart group.
Driven by these positive outcomes and strong patient-reported satisfaction scores, Eledon has finalized its regulatory framework with the FDA and plans to launch a late-stage Phase 3 clinical trial for kidney recipients in late 2026.
