R1 Therapeutics has officially launched as a new clinical-stage biopharmaceutical company, backed by an oversubscribed $77.5 million Series A financing and a strategic licensing agreement aimed at advancing a novel treatment for chronic kidney disease (CKD). The company will focus on developing AP306, an investigational therapy targeting hyperphosphatemia, a common and serious complication in CKD patients.
The financing round was co-led by Abingworth, F-Prime, and DaVita Venture Group, with additional participation from Curie.Bio, SymBiosis, and U.S. Renal Care. The funds will support R1’s global development program for AP306, including the initiation of a Phase 2b clinical trial expected to begin later this year. In parallel, R1 has secured exclusive global rights to develop and commercialize the drug outside of Greater China through a licensing agreement with Alebund Pharmaceuticals.
AP306 represents a first-in-class approach to treating hyperphosphatemia by targeting the active transport of phosphate in the gastrointestinal tract. This mechanism distinguishes it from existing therapies, which primarily rely on binding phosphate to limit its passive absorption. Current standard treatments, including phosphate binders, have remained largely unchanged for decades and are often associated with limitations such as high pill burden, poor tolerability, and suboptimal patient adherence.
Hyperphosphatemia remains a significant challenge in CKD management, particularly among patients undergoing dialysis. In the United States alone, more than 500,000 individuals receive dialysis treatment, and globally the number exceeds four million. Despite available therapies, over 40% of patients fail to achieve recommended phosphate control targets, increasing the risk of bone disorders, cardiovascular complications, and mortality.
Early clinical data for AP306 have shown promising results. A Phase 2a study conducted in dialysis patients demonstrated a significant reduction in serum phosphate levels, along with favorable safety and tolerability outcomes. These findings, published in a peer-reviewed medical journal, support further clinical development of the therapy.
R1 Therapeutics is led by Co-Founder, President, and CEO Dr. Krishna Polu, a nephrologist with more than two decades of experience in the biopharmaceutical sector. He is joined by Co-Founder and Chief Operating Officer Dr. L. Mary Smith, a seasoned biotech executive with prior leadership roles in drug development.
Dr. Polu emphasized that AP306 has the potential to transform treatment paradigms by offering improved efficacy with a lower pill burden compared to current therapies. He suggested that, if successful, the drug could redefine phosphate-lowering treatments for CKD patients.
Alebund Pharmaceuticals CEO Gavin Xia also highlighted the partnership’s significance, noting the large unmet need among CKD patients struggling with inadequate phosphate control. He expressed confidence that the collaboration with R1 Therapeutics could help bring a much-needed innovation to the global market.
With investigational new drug applications already active in both the United States and China, AP306 is positioned to advance through the next stages of clinical development, offering hope for improved outcomes in a large and underserved patient population.