SpliceBio Secures $135M Series B to Advance Gene Therapy for Stargardt Disease

SpliceBio announced the closing of a $135 million Series B financing round to support the clinical advancement of SpliceBio’s lead gene therapy candidate, SB-007, for Stargardt disease. There are currently no approved treatments for the disease, which is caused by mutations in the ABCA4 gene. SB-007, based on SpliceBio’s proprietary Protein Splicing platform, is designed to deliver a full-length, functional ABCA4 protein using a dual adeno-associated viral (AAV) vector approach. 

SB-007 is the first dual AAV gene therapy for Stargardt disease cleared by the FDA to enter clinical development. The therapy also received regulatory clearance from the UK’s Medicines and Healthcare products Regulatory Agency (MHRA). The company is currently conducting two studies: the interventional phase 1/2 ASTRA study and the observational POLARIS study. 

The round was co-led by new investors EQT Life Sciences and Sanofi Ventures, and joined by Roche Venture Fund as well as all existing backers: New Enterprise Associates (NEA), UCB Ventures, Ysios Capital, Gilde Healthcare, Novartis Venture Fund, and Asabys Partners.

“This financing marks a pivotal milestone for SpliceBio as we advance the clinical development of SB-007 and continue to expand our pipeline across ophthalmology, neurology and beyond,” said Miquel Vila-Perello, PhD, CEO and Co-Founder of SpliceBio. “The support from such high-quality investors underscores the strength of our programs and our unique Protein Splicing platform, which has the potential to unlock gene therapies for diseases previously deemed untreatable.”

According to a company news release, SpliceBio's 'Protein Splicing' technology addresses a fundamental challenge in the field of gene therapy: the limited 4.7 kilobase packaging capacity of AAV vectors. Many diseases are caused by mutations in large genes that exceed this limit. SpliceBio solves this by splitting the gene into multiple segments delivered by separate AAV vectors. Once inside the cell, proprietary engineered inteins—originally developed at Princeton University—splice the resulting proteins together, recreating the full-length therapeutic protein.

The Series B proceeds will also accelerate the development of SpliceBio’s broader pipeline of gene therapy candidates targeting additional ophthalmologic, neurologic, and undisclosed indications.