Phase 2 findings point to a possible shift in transplant immunosuppression
A phase 2 clinical trial has found that tegoprubart, an anti-CD40L antibody therapy, preserved kidney function better than tacrolimus in adults receiving their first kidney transplant. The results come from the BESTOW trial and are scheduled for presentation at ASN Kidney Week 2026.
Tacrolimus is a current standard component of immunosuppressive treatment after transplantation. It helps prevent organ rejection, but the source describing the trial notes that it can carry substantial side effects, including kidney toxicity, hypertension, diabetes, tremors and brain fog.
The findings do not establish a new standard of care. They are from a phase 2 trial and are being presented at a medical meeting. But they provide an early clinical signal for a treatment approach intended to prevent rejection while potentially reducing some of the burdens associated with tacrolimus-based therapy.
Kidney function remained higher through 18 months
In BESTOW, kidney graft function stabilized after the first month of treatment. It remained higher among patients treated with tegoprubart than among those receiving tacrolimus at every reported time point, according to the trial summary.
The reported kidney-function advantage was statistically significant at 18 months. That outcome is particularly relevant in kidney transplantation, where maintaining graft function is central to the long-term success of the transplant and to patients’ health after surgery.
The study involved 127 treated patients. Of those, 107 completed study treatment through week 52: 51 people taking tegoprubart and 56 taking tacrolimus. The completion figures describe the participants who remained on their assigned study treatment through that point; they do not by themselves answer every question about the therapy’s broader safety or effectiveness.
How tegoprubart differs
Tegoprubart works by targeting the CD40L pathway, which is central to communication between immune cells. That mechanism is the basis for its proposed role in an immunosuppressive regimen for transplant recipients.
Andrew Adams of the University of Minnesota Medical School, the study’s corresponding author, said the new therapy has the potential to replace tacrolimus across transplant types. That is a forward-looking interpretation rather than a conclusion that the phase 2 results alone can settle. The available findings specifically concern adults receiving their first kidney transplant.
Quality-of-life results add another measure
A recent analysis of BESTOW data also compared patient-reported health-related quality of life. At week 52, patients receiving tegoprubart showed improvements from baseline across all five reported subscales. Patients receiving tacrolimus improved across four of the five subscales.
The tegoprubart group had greater improvements on a mental component summary. It also had a numerically greater reduction in total symptom score from baseline. These measures do not replace clinical outcomes such as kidney function, but they add context about how participants reported their health and symptoms while on treatment.
For transplant medicine, that distinction is important. A regimen’s value is not limited to whether it suppresses rejection; the day-to-day effects of treatment can shape patients’ ability to live with a transplanted organ and with long-term medication use. The BESTOW analysis suggests that quality-of-life outcomes should remain part of the evaluation as the treatment is studied further.
Why the result deserves caution
The data are encouraging, but they are preliminary in several practical senses. BESTOW is a phase 2 trial, and the findings cited here are due to be presented at ASN Kidney Week rather than described as final evidence from a later-stage program. The supplied report does not provide a complete accounting of rejection outcomes, adverse events, longer-term durability or how tegoprubart would compare across other transplant populations.
It is also focused on first-time kidney-transplant recipients. Claims about use in other organ transplants will require their own supporting evidence. The trial’s kidney-function and patient-reported outcomes are meaningful signals, but they are not a substitute for the larger and longer studies needed to assess a potential change in routine treatment.
What comes next
- Further study will need to confirm the kidney-function benefit in larger populations.
- Longer follow-up will be important for evaluating the durability of graft outcomes.
- Safety, rejection prevention and treatment tolerability will remain central questions.
- Any expansion beyond first-time kidney transplantation will require dedicated evidence.
For now, BESTOW offers evidence that an anti-CD40L approach may preserve kidney function better than tacrolimus in the population studied, while also producing stronger results on several patient-reported measures. The presentation at ASN Kidney Week will put those results before the nephrology community, where the next question will be whether subsequent research can validate them strongly enough to change clinical practice.
This article is based on reporting by Medical Xpress. Read the original article.
Originally published on medicalxpress.com
