Kidney disease biotech R1 Therapeutics launches with oversubscribed $77.5M Series A
What's the deal? R1 Therapeutics, a Redwood City, California-based clinical-stage biotech, has launched with an oversubscribed $77.5M Series A to develop AP306 — a potential first-in-class pill for a dangerous complication of chronic kidney disease (CKD).
The round was co-led by AbingworthDealroom has a profile for this one. Try Dealroom →, F-Prime, and DaVita Venture GroupDealroom has a profile for this one. Try Dealroom →, with participation from Curie.BioDealroom has a profile for this one. Try Dealroom →, SymBiosisDealroom has a profile for this one. Try Dealroom →, and US Renal CareDealroom has a profile for this one. Try Dealroom →. At the helm is Krishna PoluDealroom has a profile for this one. Try Dealroom →, a nephrologist and biotech veteran with over 20 years of industry experience.
Why now? The target condition, hyperphosphatemia — a build-up of phosphate in the blood — affects the majority of dialysis patients and, if uncontrolled, drives serious bone and heart complications. Over 500,000 Americans are on dialysis, yet more than 40% fail to hit treatment targets.
The drugs currently used have barely changed in 60 years: they work by binding phosphate in the gut and are notorious for requiring patients to swallow handfuls of pills with every meal, with poor results.
AP306 works differently, blocking the body's own mechanism for absorbing phosphate rather than just mopping it up. Early trial data published in early 2025 showed patients on AP306 were around 20% more likely to reach recommended phosphate levels than those on Sanofi's widely used Renvela.
What could go wrong? AP306 still has a long road to approval, and mid-stage trial success is far from guaranteed. It will also need to prove it can beat cheap, entrenched generics on both results and cost. The financial terms of the Alebund licensing deal remain undisclosed. And running a global trial in partnership with a Chinese biotech — which retains rights in Greater China — adds execution complexity.
The signal: R1's launch reflects growing investor appetite for kidney care, a long-underserved field with a massive patient population. The backing of DaVita Venture Group and US Renal Care — two of the largest dialysis providers in the US — gives R1 real-world clinical reach from day one.
More broadly, the deal is a clean example of a rising playbook in biotech: Western startups licensing Chinese-developed drugs with existing trial data, shaving years off development timelines.
Sources:
R1 Therapeutics
GlobeNewswire
Fierce Biotech
Reuters
Biopharma Dive
BioSpace
Endpoints News
Image credit:
R1 Therapeutics
J.V.
