Biogen-backed Estuary nabs $93M for kidney disease gene therapy

Estuary Biotherapeutics, a California genetic medicines developer founded in 2022 around Yale research by Stefan Somlo and Michael Caplan, has launched with a $93 million Series A led by RA Capital Management, with participation from Deep Track Capital, 4BIO Capital and Alphabet's GV. Its lead gene therapy programs, EST-201 and EST-101, target autosomal dominant polycystic kidney disease by restoring polycystin function, with human testing expected in 2027 and 2028. Only one drug, tolvaptan, is currently approved for ADPKD, which affects roughly 1 in 400 to 1,000 people.