FOR IMMEDIATE RELEASE

SANTA BARBARA, CA – May 20, 2026 – Santa Barbara Nutrients (SBN) is pleased to announce the 12-month interim results from an ongoing clinical trial evaluating the safety and efficacy of SBN’s medical food KetoCitra® in combination with a structured ketogenic nutrition and lifestyle program in individuals with moderate-to-advanced Autosomal Dominant Polycystic Kidney Disease (ADPKD). The new results were presented at the World Congress of Nephrology (WCN 2026) and extend and reinforce the previous, highly encouraging three-month interim data reported earlier this year.

A Year of Sustained Organ Volume Reduction

This study — the first clinical investigation in Asia of a ketogenic metabolic intervention for ADPKD — is led by Dr. Shigeo Horie and Dr. Haruna Kawano at Juntendo University in Tokyo, Japan, in collaboration with Santa Barbara Nutrients. Building on the earlier 3-month interim analysis — which already showed a statistically significant reduction in Total Kidney Volume (TKV) at the first imaging timepoint — the 12-month data demonstrate that these benefits are sustained over a full year of intervention and extend beyond the kidneys to the liver, a commonly affected organ in ADPKD.

Ten ADPKD patients (Mayo Imaging Class C or higher; median age 44 years; median baseline eGFR 57 mL/min/1.73 m²) followed the ketogenic diet protocol under multidisciplinary clinical supervision, with individualized guidance from dietitians trained in ketogenic therapies and incorporation of KetoCitra® to supply exogenous beta-hydroxybutyrate (BHB) and alkaline citrate. Three of the ten participants chose to discontinue the ketogenic diet at the end of the 3-month education program and return to their usual diet, while seven continued the intervention through 12 months. MRI-based volumetric measurements and laboratory parameters were assessed at baseline, 3 months, and 12 months.

Key 12-month interim findings include:

•      Sustained Kidney Volume Reduction in 12-Month Completers: Among the seven participants who maintained the intervention for the full year, Total Kidney Volume (TKV) significantly decreased at 12 months (paired t-test p = 0.026; Wilcoxon p = 0.016) — a striking departure from the typical natural history of Mayo Class C ADPKD, in which TKV is expected to grow by approximately 5–10% per year.

•      Significant Liver Volume Reduction: Total Liver Volume (TLV) significantly decreased at both 3 and 12 months across the full cohort (Wilcoxon p = 0.049 at 12 months). Liver enlargement is a common and burdensome extra-renal manifestation of ADPKD.

•      Stable Kidney Function: No significant change in eGFR was observed over the treatment period — a meaningful result in a cohort with advanced baseline disease and a historical pre-trial eGFR decline of approximately −5.6 mL/min/1.73 m²/year.

•      Strong Ketone–Volume Dose-Response Relationship: Mean blood ketone levels at 3 months showed a strong, statistically significant negative correlation with TKV change in the 12-month completers (Spearman’s ρ = −0.86, p = 0.012). Higher ketone levels were associated with greater attenuation of kidney volume expansion, providing mechanistic evidence suggesting that BHB itself is a key driver of the benefit.

•      Kidney and Liver Respond Through Partially Distinct Pathways: While kidney volume change tracked most closely with ketone levels, liver volume change correlated more strongly with weight and body-fat reduction — suggesting that, although the overall metabolic intervention benefits both organs, the underlying mechanisms may not be identical.

•      Tolerability: Ketogenic metabolic therapy incorporating KetoCitra® was well tolerated in this Japanese ADPKD cohort.

These interim results were presented at the World Congress of Nephrology 2026 (abstract WCN26-7921, published in Kidney International Reports).

A Qualitatively Different Magnitude of Effect

The 12-month results are best understood in the context of what has previously been achievable in ADPKD. In the landmark TEMPO 3:4 trial — the pivotal phase 3 study that led to regulatory approval of tolvaptan, the only pharmacotherapy currently approved for ADPKD — tolvaptan reduced the annual rate of TKV growth from +5.51% per year on placebo to +2.80% per year on tolvaptan. In other words, the best available drug slows the rate at which kidneys continue to grow, but they still grow.

In the Juntendo 12-month completers, TKV decreased — not slowed, not stabilized, but reduced. The magnitude of effect is on a different axis altogether from what pharmacotherapy has been able to produce. While these are early-phase, single-arm, interim data in a small cohort and require confirmation in the planned controlled comparison, the qualitative difference is striking: a metabolic intervention is producing kidney volume reductions that no drug has been shown to achieve.

From Mechanism to Disease-Modifying Therapy: The Role of KetoCitra® and Ren-Nu™

The trial design integrates KetoCitra® with a structured, dietitian-led nutrition program, a rigorous curriculum, personal consultations, and digital self-monitoring of ketones, glucose, and nutrient intake. KetoCitra® delivers exogenous beta-hydroxybutyrate to support nutritional ketosis, together with alkaline citrate to help normalize urinary citrate and pH — reducing the risk of calcium oxalate and uric acid microcrystal formation that can otherwise accompany metabolic shifts.

This same combination is the foundation of Ren-Nu™, SBN’s dietitian-led nutrition program already offered to individuals with ADPKD. Ren-Nu™ provides the educational and clinical framework for patients to reach nutritional ketosis safely, emphasizing low-oxalate intake and renal-safe nutrient ratios. The Juntendo findings provide the most rigorous 12-month clinical evidence to date that this combined approach can favorably alter the natural history of ADPKD.

Expert Commentary

“The 12-month data strengthen the case that ketogenic metabolic therapy is doing something fundamentally different from conventional approaches to ADPKD,” said Dr. Thomas Weimbs, Chief Scientific Officer of Santa Barbara Nutrients and Professor at the University of California, Santa Barbara. “Seeing total kidney volume actually decrease — rather than continue to expand — over a full year in patients with advanced disease is something that no pharmacotherapy has been shown to achieve. The best available drug only slows kidney growth but the kidneys continue to enlarge. Here we are seeing them get smaller. Equally important is the strong dose-response relationship between blood ketone levels and the magnitude of kidney volume reduction. That is precisely what we would predict from the underlying biology, in which beta-hydroxybutyrate acts as a signaling molecule that suppresses cyst growth.”

Looking Ahead

The Juntendo trial has completed enrollment of over 50 participants in the intervention group, and an additional control group, to confirm and extend these findings in a larger, controlled setting. Final results are expected in about a year. SBN remains committed to advancing rigorous clinical evidence for metabolic approaches to ADPKD and to making KetoCitra® and the Ren-Nu™ program broadly accessible to the global PKD community.

About Santa Barbara Nutrients

Santa Barbara Nutrients is a Public Benefit Corporation dedicated to bringing science-based metabolic therapies to the kidney community. Its flagship offerings, the Ren-Nu™ program and KetoCitra®, represent the frontier of metabolic nephrology.

For more information, please visit www.SantaBarbaraNutrients.com, Ren-Nu.org, or contact info@sbnutrients.com.