Eledon Pharmaceuticals (NASDAQ:ELDN) executives discussed recent clinical results and upcoming regulatory plans for its investigational immunosuppressive therapy, referred to in the discussion as “tego,” highlighting data from the company’s Phase II BESTOW kidney transplant study, longer-term follow-up from an earlier trial, and progress across islet cell transplantation and xenotransplant collaborations.
Phase II BESTOW kidney transplant data: endpoint context and safety
The company said it remains “very excited” about outcomes from the Phase II, open-label BESTOW study, which was presented at the American Society of Nephrology (ASN) meeting last year. Management noted the study’s primary endpoint was kidney function and said it did not meet that endpoint, but added that kidney function comparisons versus standard of care were favorable “in every single aspect” on deeper review of the data.
On kidney function, management pointed to subgroup analyses that showed what it described as a “10-point delta” that would have met the study’s kidney function endpoint, except for an imbalance in randomization tied to donor kidney quality (KDPI). The company said one subgroup contained “really great quality kidneys” that were imbalanced between arms and included an approximate 10-year donor age difference between the control group and the tego arm, which it said affected tacrolimus performance in that population. Management said excluding that subgroup would have resulted in meeting the kidney function endpoint, though it characterized this as post hoc analysis.
The company characterized safety as a key “home run” from BESTOW, citing multiple numerical differences favoring tego compared with calcineurin inhibitor-based standard of care. Management highlighted:
- A “ninefold” difference in tremors (described as a major issue with calcineurin inhibitors)
- A “sevenfold” difference in infection rates with bacteremia
- “Two- to four-fold” differences in sepsis and delayed graft function
- A “twofold” difference in certain cardiovascular events
Management also said infection rates for CMV and BK were the same between the standard-of-care and tego arms.
Acute rejection rates and protocol execution
In response to investor questions about acute rejection, management said there was a numerical difference between the arms: 20% in the tego arm versus 14% in the tacrolimus arm. However, it noted that 100% of rejections in the tego arm occurred within the first six months, with none observed after that point.
For the tacrolimus arm, management said only 40% of rejections were identified in the first 12 months, with most captured during the protocol-specified 12-month biopsy. The company suggested this pattern indicated differences in how biopsies were triggered based on changes in kidney function during the study.
Looking ahead, the company said it plans to work closely with sites and investigators in Phase III to ensure the protocol is “balanced” between arms so that rejection detection and management do not differ based on treatment assignment.
Longer-term Phase I follow-up and rationale for Phase III design
The company also discussed 24-month follow-up from an open-label Phase I study, describing the results as “really, really exciting.” Management said no additional rejections were observed during longer-term follow-up and reported 100% survival in the smaller group discussed. It also said estimated glomerular filtration rate (eGFR) remained “really, really good,” describing stable or increasing eGFR over time as notable given management’s view that tacrolimus can be toxic to the transplanted organ over time.
Management said long-term follow-up will continue not only from the Phase I trial but also from both arms of BESTOW via a long-term extension option. The company said sharing those longer-term data with regulators will be important to support the case for improving long-term outcomes relative to current standard of care.
FDA timing and Phase III planning; added quality-of-life measures
On regulatory timing, management said it is preparing briefing book materials and expects to complete them in the first quarter, then request an end-of-Phase II meeting with the FDA in late Q1 or early Q2. The company said it is still guiding to launch a Phase III registrational trial by the end of the year, though it cautioned that plans may change after FDA discussions.
Management said the Phase III study would be powered to the long-established composite endpoint (biopsy-proven rejection and patient/graft survival at 12 months) under a non-inferiority design. It also said it expects to formally capture key toxicities associated with standard of care—such as new-onset diabetes and tremors—as secondary endpoints.
A new element the company plans to incorporate is patient-reported outcomes. Management said BESTOW did not formally capture patient-reported outcomes, and it intends to include formal quality-of-life endpoints in Phase III to better quantify the impact of safety and tolerability differences on patients.
Management also cited lessons learned from BESTOW regarding investigator management of immunosuppression. It described imbalances between arms in ATG induction dosing, bolus methylprednisolone dosing around transplant, and prednisone taper timing—saying the steroid wean “ironically favored” tacrolimus over tego because investigators weaned prednisone faster in the tego arm. It further said physicians often adjust methylprednisolone and mycophenolate mofetil (MMF) in response to BK viremia, CMV, neutropenia, and leukopenia, and argued Phase III should include tighter guidance to prevent overcorrections that could raise rejection risk.
Pipeline updates: islet cell transplant and xenotransplant collaborations; cash runway
Beyond kidney transplant, management discussed an islet cell transplant program being followed publicly by an investigator on social media. It cited a recent update from Dr. Rutkowski indicating nine patients have been enrolled; seven have come off exogenous insulin, and an eighth was described as “pretty close.” Management said the function seen in the islet cell transplant setting under the company’s drug “has really never been seen before” and reported no safety issues in the study to date. It described the approach as a “functional cure” for people with Type 1 diabetes and said it is working toward converting the investigator-initiated effort into a sponsored study in 2026.
On regulatory planning for islet cell transplantation, management said the FDA has provided “pretty specific guidance” for a new immunosuppressive regimen, describing a Phase I/II/III bridging-type design. The company said it expects to file an IND by the end of the year and indicated it anticipates a separate FDA meeting later in the year to discuss the islet cell path.
In xenotransplant, management said it has preclinical collaborations globally across multiple organs, including kidney, heart, and heart valves, and called the preclinical data encouraging. It referenced United Therapeutics and eGenesis having INDs intended to transition xenotransplant work from compassionate use to formally sponsored studies, and said eGenesis plans to roll into sponsored studies in 2026, with Eledon continuing to support them. Management said it has not yet discussed its own regulatory path with the FDA for xenotransplant, but expects to supply tego as part of an immunosuppressive regimen, leveraging safety and efficacy data generated under a partner’s IND to support approval for prevention of xenotransplant rejection.
The company also discussed the broader potential impact of xenotransplant as a bridge strategy given organ shortages, citing roughly 100,000 people on the kidney transplant waiting list and noting many may never receive an organ. As an example, management referenced a patient (“Mr. Andrews”) transplanted at Massachusetts General Hospital who lost a xenograft around nine months post-transplant but was subsequently bridged to an allotransplant and discharged about a day and a half later, with management saying he is “doing fantastic.”
On capital, management said the company has cash through the second quarter of 2027. It outlined expected milestones supported by that runway, including the FDA end-of-Phase II discussion and Phase III planning in kidney transplant, moving islet cell transplantation toward a sponsored study, continued support for University of Chicago studies (including a second islet study in a Type 1 diabetes population with kidney dysfunction), a potential investigator-initiated liver transplant study, and ongoing xenotransplant support.
About Eledon Pharmaceuticals (NASDAQ:ELDN)
Eledon Pharmaceuticals, Inc (NASDAQ:ELDN) is a clinical-stage biopharmaceutical company focused on the discovery and development of therapies for diseases characterized by smooth muscle dysfunction. The company leverages a proprietary ion-channel modulation platform to identify and optimize small-molecule compounds that can either restore or inhibit smooth muscle activity, with the goal of addressing gastrointestinal, hepatic and cardiovascular disorders.
Eledon’s pipeline comprises several preclinical and early-phase clinical programs targeting high-unmet-need indications.
