R1 Therapeutics Inc of California, US, has made its market debut with $77.5 million in venture finance and an exclusive global license to develop and commercialise a new product for a disorder caused by chronic kidney disease. Announced on 17 March, the financing was co-led by Abingworth LLP of the UK, F-Prime Capital of Cambridge, US, and the US DaVita Venture Group.
The new product, AP306, is a small molecule drug for the treatment of hyperphosphatemia, a disorder that arises when the kidneys cannot filter excess phosphorus from the blood. The condition particularly affects kidney patients on dialysis who represent up to four million people worldwide, according to the company. Current treatments for hyperphosphatemia include sevelamer carbonate (Renvela), a small molecule drug that works by attaching to dietary phosphorus in the intestine to prevent its absorption into the bloodstream. AP306 appears to improve on current treatments by inhibiting multiple phosphate transporters at the same time. This has been observed in a Phase 2a study of dialysis patients receiving AP306 compared with those on sevelamer carbonate. The results, published in the May 2025 edition of Kidney International Reports, showed that serum phosphate levels were significantly lower in the AP306 group than in the sevelamer group at 12 weeks. No serious adverse events were reported.
R1 Therapeutics has in-licensed AP306 from China-based Alebund Pharmaceuticals Ltd. Proceeds of the funding will be used for a Phase 2b study later this year.
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