Abstract: TH-PO0095
Trial in Progress: A Phase 2b, Randomized, Double-Blind, Placebo-Controlled Study Evaluating AP306 for Hyperphosphatemia in Patients Receiving Maintenance Hemodialysis
Session Information
- Fluid, Electrolyte, and Acid-Base Disorders: Clinical Research
October 22, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Fluid, Electrolytes, and Acid-Base Disorders
- 1102 Fluid, Electrolyte, and Acid-Base Disorders: Clinical
Authors
- Block, Geoffrey A., US Renal Care Inc, Decatur, Georgia, United States
- Moe, Sharon M., Indiana University School of Medicine, Indianapolis, Indiana, United States
- Zuo, Li, Peking University People's Hospital, Beijing, China
- Ketteler, Markus, Robert-Bosch-Krankenhaus GmbH, Stuttgart, BW, Germany
- Sinha, Smeeta, Northern Care Alliance NHS Foundation Trust, Salford, England, United Kingdom
- Trotman, Marie-Louise, R1 Therapeutics, San Diego, California, United States
- Lim, Allison, R1 Therapeutics, San Diego, California, United States
- Zhang, Weifeng, Shanghai Alebund Pharmaceuticals Co Ltd, Shanghai, China
- Zhang, Huading, Shanghai Alebund Pharmaceuticals Co Ltd, Shanghai, China
- Xia, Gavin G., Shanghai Alebund Pharmaceuticals Co Ltd, Shanghai, China
- Smith, L. Mary, R1 Therapeutics, San Diego, California, United States
- Polu, Krishna, R1 Therapeutics, San Diego, California, United States
- Chertow, Glenn M., Stanford University School of Medicine, Stanford, California, United States
Background
Hyperphosphatemia remains a persistent challenge in patients with chronic kidney disease receiving maintenance hemodialysis, despite the availability of multiple phosphate-lowering therapies. Limitations of current therapies include high pill burden, gastrointestinal intolerance, and suboptimal phosphate control. AP306 is an investigational pharmaceutical agent, first-in-class, orally administered pan-phosphate active transport inhibitor. AP306 was previously evaluated in a phase 2a trial and resulted in improved phosphate control compared to sevelamer. This study will evaluate fixed doses of AP306 administered three times (TID) or two times daily (BID).
Methods
This is a Phase 2b, multicenter, randomized, double-blind, placebo-controlled, parallel-group trial evaluating the safety, tolerability, and efficacy of fixed-dose AP306 in adult participants with hyperphosphatemia undergoing maintenance hemodialysis. Approximately 168 participants will be enrolled.
Eligible participants (≥18 years) on maintenance hemodialysis will discontinue existing phosphate-lowering therapies prior to randomization. Participants will be randomized at equal allocation ratio to receive AP306 at fixed doses (75mg, 100mg, or 125mg TID; or 75mg, 125mg or 150mg BID) or placebo for 8 weeks with a 4-week follow-up period.
The primary endpoint is change in serum phosphate from baseline to end of treatment (or prior to rescue therapy or the interruption of study treatment due to serum phosphate <2.5mg/dL). A key secondary endpoint is the achievement of serum phosphate concentrations within the target range (3.5 to 5.5mg/dL) at any time during the treatment period. Safety assessments include treatment-emergent adverse events, laboratory parameters, and electrocardiograms. Rescue therapy is permitted for persistently elevated serum phosphate concentrations ≥8.5mg/dL after at least 4 weeks of treatment.
Results
This trial is currently ongoing in the US and China. No efficacy or safety results are available at this time.
Conclusion
This trial will evaluate the efficacy and safety of AP306, a novel investigational treatment for hyperphosphatemia in participants receiving maintenance hemodialysis. Results from this trial will inform the design of a planned Phase 3 trial and elucidate the potential role of AP306 in the management of hyperphosphatemia.
Funding
- Commercial Support – R1 Therapeutics