# R1 Therapeutics

Startup profile on Capital Atlas: https://capitalatlas.ai/startups/r1-therapeutics

- Industry: Biotechnology
- Headquarters: San Francisco, US
- Website: www.r1therapeutics.com
- Total disclosed funding: $81M
- Latest round: Series A (Sep 30, 2026)
- Investors on record: 7

## About

R1 Therapeutics Ltd, based in the US, develops innovative therapies aimed at improving patient outcomes for those suffering from kidney disease, particularly focusing on hyperphosphatemia associated with chronic kidney disease (CKD).R1 Therapeutics Ltd specializes in the development of therapies for kidney disease. In September 2026, R1 Therapeutics Ltd raised USD 3 million in series A funding from Samsara BioCapital. This funding round was co-led by Abingworth, F-Prime Capital, and DaVita Venture Group, with participation from other investors such as Curie.Bio, Symbiosis, and U.S. Renal Care, Inc. R1 Therapeutics has completed one deal to date, reflecting a focused strategy on advancing their therapeutic offerings in the renal space.R1 Therapeutics specializes in developing innovative therapies for patients with kidney disease, primarily focused on hyperphosphatemia associated with chronic kidney disease (CKD). The company's lead product, AP306, is a first-in-class pan phosphate transporter inhibitor designed to block the active transport of phosphate in the gastrointestinal tract, targeting three key transporters: NaPi-IIb, PiT-1, and PiT-2. This mechanism aims to provide rapid phosphate lowering while reducing treatment burden for patients who rely on traditional phosphate binders. The primary end-users of AP306 are CKD patients, particularly those undergoing dialysis, with anticipated geographical markets including the United States and potential expansion to regions with high kidney disease prevalence.R1 Therapeutics operates in the biotechnology sector, particularly within the renal therapeutics market. The revenue model relies on partnerships with healthcare providers and pharmaceutical collaborations, including licensing agreements for AP306. As a prescription medication, AP306 is expected to be marketed to hospitals, dialysis centers, and specialty pharmacies serving CKD patients. The company will use the September 2026 funding to advance development of AP306.

## Funding rounds

- Series A, Sep 30, 2026, $3M — Samsara BioCapital
- Series A, Mar 17, 2026, $78M — Abingworth, F-Prime Capital, U.S. Renal Care, Inc., DaVita Venture Group, Curie.Bio, Symbiosis

## Investors

- Abingworth (https://capitalatlas.ai/funds/abingworth) — Series A
- F-Prime Capital (https://capitalatlas.ai/funds/f-prime-capital) — Series A
- U.S. Renal Care, Inc. — Series A
- DaVita Venture Group (https://capitalatlas.ai/funds/davita-venture-group) — Series A
- Curie.Bio (https://capitalatlas.ai/funds/curie-bio) — Series A
- Symbiosis — Series A
- Samsara BioCapital (https://capitalatlas.ai/funds/samsara-biocapital) — Series A