Estuary Biotherapeutics is seeking to address the root cause of autosomal dominant polycystic kidney disease with two gene therapy programs based on science from Yale.
Estuary Biotherapeutics is ready to sail the seas, with $103 million in financing and two lead gene therapy programs for kidney disease.
The biotech emerged from stealth on Friday, announcing a $93 million series A and an earlier $10 million seed financing. Co-founder Wayne Sackett, previously of MyoKardia, will serve as CEO.
Estuary is aiming to tackle the root cause of autosomal dominant polycystic kidney disease (ADPKD), which is the most common genetic form of end-stage kidney disease worldwide. The disease causes fluid-filled cysts in the kidneys which gradually leads to a decline in function.
The company’s pipeline is built around the science of Stefan Somlo and Michael Caplan at the Yale School of Medicine. The scientists demonstrated that restoring the expression of polycystin in kidneys that have evidence of cystic disease can reverse the condition in mice.
The scientists have teamed up with Estuary to develop two distinct therapies to further test the theory. EST-201 is a full-length PKD2 gene therapy delivered via AAV that is set to enter the clinic in 2027 in patients with ADPKD whose disease has a PKD2 mutation. PKD2 is a calcium channel involved in polycystic kidney disease.
Another AAV gene therapy, EST-101 will deliver a polycystin-1 (PC1)-derived functional region. The therapy is expected to enter the clinic in 2028.
Estuary is not alone in its mission to address ADPKD. In June, SonoThera raised $125 million for a pipeline of genetic medicines that includes a gene therapy for the kidney disease.
And last year, Novartis dropped $800 million upfront to buy Regulus Therapeutics, which is developing miRNA-targeting therapies. At the center of the deal was farabursen, an oligonucleotide for ADPKD. The therapy is currently in Phase 1 testing, according to Novartis’ pipeline.
Estuary’s series A was led by RA Capital Management, with additional funds from Deep Track Capital, Biogen New Ventures and others. 4BIO Capital and GV, which contributed the original seed financing, also participated.
