Estuary Biotherapeutics raises $93 million Series A to develop gene therapies for ADPKD

Estuary Biotherapeutics, a California gene‑therapy startup backed by Biogen, announced a $93 million Series A financing led by RA Capital.

The capital will support development of two genetic medicines targeting autosomal dominant polycystic kidney disease (ADPKD), an inherited disorder that causes kidney cysts and eventual renal failure.

The program builds on research by co‑founders Stefan Somlo and Michael Caplan at Yale, who showed that reactivating polycystin proteins can shrink cysts in mouse models and that a truncated polycystin fragment is sufficient for therapeutic effect.

The company plans to use standard viral‑vector delivery platforms to transport the therapeutic DNA to patients’ kidneys, aiming to translate the pre‑clinical findings into clinical candidates.