Estuary Biotherapeutics emerged from stealth on October 16, 2026, with $103 million in total committed financing:
a $93 million Series A led by RA Capital Management and an earlier $10 million seed round.
The funding will advance two preclinical gene therapy candidates for autosomal dominant polycystic kidney disease (ADPKD), an inherited condition that causes kidney cysts and can lead to kidney failure.
EST-201 is an AAV-delivered, full-length PKD2 gene therapy for patients with PKD2 mutations; Estuary anticipates clinical entry in 2027.
EST-101 uses the same AAV approach to deliver a functional region derived from the PKD1-encoded polycystin-1 protein; clinical entry is anticipated in 2028.
The Series A included Deep Track Capital, Biogen New Ventures, UPMC Enterprises, Pivotal bioVenture Partners, the National Kidney Foundation Innovation Fund, and others; seed investors GV and 4BIO Capital also participated.
Both programs remain investigational. Their proposed benefits, including restoring polycystin function in kidney cells, have not yet been demonstrated in human trials.
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Estuary Biotherapeutics Launches with $103 Million ...
Estuary flows out of stealth with $103M to propel kidney disease gene therapies into clinic
Estuary sails into kidney disease space with $103M for ...
Estuary Biotherapeutics emerges with $103M for kidney disease drugs
Estuary Launches With $103m To Advance Kidney-Directed Gene Therapies
ADPKD Gene Therapy Development at Newly Launched ...
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ADPKD Gene Therapy Development at Newly Launched Estuary Biotherapeutics
Estuary Biotherapeutics Launches with $103M to Advance ...
Estuary Biotherapeutics Launches With $103 Million for ...
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