Eledon Pharmaceuticals Presents Long-Term Phase 2 BESTOW Data Showing Tegoprubart Benefits Over Tacrolimus in Kidney Transplant

Eledon Pharmaceuticals presented long-term extension results from its Phase 2 BESTOW trial at the American Transplant Congress, showing that patients treated with the investigational immunosuppressive tegoprubart maintained significantly higher kidney function and reported improved symptoms compared to those receiving standard tacrolimus therapy.

Tegoprubart-treated patients demonstrated a statistically significant advantage in estimated glomerular filtration rate (eGFR). At month 18, the mean eGFR was approximately 12 mL/min/1.73 m² higher for the tegoprubart group compared to the tacrolimus group (74 vs. 61 mL/min/1.73 m²; p<0.05). Kidney graft function stabilized after the first month of treatment and remained higher in tegoprubart-treated patients at each reported time point.

The trial also showed a favorable rejection profile. No biopsy-proven acute rejection (BPAR) events were observed in tegoprubart-treated patients after the first six months post-transplant. In contrast, the tacrolimus arm experienced seven BPAR events, representing 9.4% of that group, with most occurring after six months. Patient-reported outcome measures at 52 weeks favored tegoprubart, with statistically significant improvements on two validated scales of symptom burden, including the Modified Transplant Symptom Occurrence and Symptom Distress Scale (MTSOSD-59R) and the KDQOL-36 Symptoms and Problems domain.

Safety analysis revealed lower rates of key adverse events in the tegoprubart arm. Central nervous system and kidney-related events, including headache (12% vs. 2%), extremity pain (10% vs. 0%), fall or loss of balance (6% vs. 0%), and acute kidney injury (6% vs. 2%), were more frequent in the tacrolimus group. Diarrhea was also more common with tacrolimus (21% vs. 10%). The company highlighted other numerical differences favoring tegoprubart, such as a "ninefold" difference in tremors and a "sevenfold" difference in bacteremia infection rates. No graft loss, progressive multifocal leukoencephalopathy, post-transplant lymphoproliferative disorder, or new malignancies were reported.

Management discussed subgroup analyses indicating a "10-point delta" in kidney function that would have met the study’s primary endpoint, except for an imbalance in donor kidney quality between the treatment arms. The company also noted that while acute rejection rates were 20% in the tegoprubart arm versus 14% in the tacrolimus arm, 100% of tegoprubart rejections occurred within the first six months, whereas most tacrolimus rejections were identified during a protocol-specified 12-month biopsy.

Looking ahead, Eledon has established a regulatory framework for a Phase 3 kidney transplantation program following a successful FDA End-of-Phase 2 meeting. The planned Phase 3 study will be powered to a composite endpoint of biopsy-proven rejection and patient/graft survival at 12 months under a non-inferiority design. Secondary endpoints will formally capture key toxicities associated with standard of care, such as new-onset diabetes and tremors, and will include patient-reported outcomes.

The company is preparing briefing book materials and expects to request an end-of-Phase 2 meeting with the FDA in late Q1 or early Q2. It is guiding to launch the Phase 3 registrational trial by the end of the year, though plans may change after FDA discussions. Longer-term follow-up from Phase 1 showed no additional rejections after six months, 100% survival, and stable or increasing eGFR over time, supporting the rationale for the Phase 3 design.