Phase II BESTOW trial: Tegoprubart vs tacrolimus for prevention of kidney transplant rejection

Results from the multicenter, randomized, open-label, active-controlled, phase II BESTOW trial (NCT05983770) and subsequent BESTOW EXTENSION (NCT06126380), evaluating tegoprubart vs tacrolimus in adult kidney transplant recipients, were presented at the 31st International Congress of The Transplantation Society (TTS), September 20–23, 2026, Sydney, AU, by Andrew Adams. In BESTOW, patients (N = 127) were randomized to tegoprubart (n = 63) or tacrolimus (n = 64). The primary endpoint was mean estimated glomerular filtration rate (eGFR) at Month 12. BESTOW EXTENSION evaluated long-term safety and efficacy.

Key data: At Month 12, mean ± standard error of the mean (SEM) eGFR was 69 ± 2.8 mL/min/1.73 m² with tegoprubart vs 66 ± 3.1 mL/min/1.73 m² with tacrolimus (p > 0.05). Among patients who completed their assigned treatment and continued in BESTOW EXTENSION, mean ± SEM eGFR at Month 24 was 71 ± 3.6 mL/min/1.73 m² with tegoprubart vs 58 ± 3.7 mL/min/1.73 m² with tacrolimus (p < 0.05). At Month 12, new-onset diabetes mellitus after transplantation (NODAT; 2.2% vs 15.9%), tremor (1.6% vs 25.0%), hyperkalemia (11.1% vs 26.6%), and bacteremia (1.6% vs 10.9%) occurred less frequently with tegoprubart vs tacrolimus. In BESTOW EXTENSION, new-onset diarrhea (10.2% vs 20.8%) and headache (2.0% vs 12.5%) were less frequent with tegoprubart, while cytomegalovirus (CMV) DNAemia was more frequent (12.2% vs 6.3%). No new-onset CMV disease, BK virus (BKV) nephropathy, malignancies, progressive multifocal leukoencephalopathy (PML), or post-transplantation lymphoproliferative disorder were reported during the extension. 

Key learning: In this analysis, tegoprubart was associated with improved kidney function compared with tacrolimus at Month 24 in kidney transplant recipients, supporting its continued evaluation as a potential alternative immunosuppressive therapy.