Solving Big Gene Therapy Hurdle Leads to Spain’s Biggest Biotech Series A Round

Gene therapy has a capacity problem. The engineered viruses used to deliver these therapies have limited leeway to transport genetic cargo. SpliceBio is developing technology that could enable the delivery of larger genes and has raised €50 million to support its research which includes its first goal: gene therapy for a rare, inherited eye disorder.

The Series A funding round announced on Wednesday was co-led by UCB Ventures and Ysios Capital.

Gene therapies typically reach their cellular destinations via adeno-associated viruses (AAV). Although these viral vectors continue to be the delivery vector of choice, their limited capabilities put certain diseases out of reach. Barcelona-based SpliceBio aims to enable the delivery of larger genetic cargoes by splitting the load. Biotechnology accomplishes this with a family of proteins called inteins. These proteins are responsible for protein splicing, a biochemical process that involves the cleavage and formation of peptide bonds.

Inteins as they occur in nature are not suitable for applications in human therapies. SpliceBio designs inteins to perform protein splicing. According to the company, these modified inteins allow the splicing of a protein, which is then reconstituted along its entire length inside the body. The startup’s technology is based on research from Princeton University’s Muir Lab.

SpliceBio’s main program concerns Stargardt’s disease, a rare eye disease that causes degeneration of the macula, a part of the retina. It is caused by a mutation in the ABCA4 gene, a gene too large to be carried by a single AAV vector. SpliceBio said it would use the Series A money to move its gene therapy for Stargardt disease into testing in humans. While ophthalmic applications are the startup’s primary focus, the company says its technology has been validated in “several other organs beyond the retina.”

The Princeton spin-out was originally called ProteoDesign and its original focus was cancer. In 2020, the startup was rebranded as Splice Bio after raising seed funding from Ysios and Asabys Partners. (The one-word company name overhaul appears to have happened this year.) Asabys also invested in the latest funding announced Wednesday, which SpliceBio says is the largest Series A round for a Spanish biotech company. . Other new investors in the round include New Enterprise Associates, Gilde Healthcare and Novartis Venture Fund.

“We are proud to have been involved in the business since its inception and are very impressed with the progress made to date,” Ysios managing partner Joël Jean-Mairet said in a prepared statement. “SpliceBio’s platform represents an unprecedented opportunity to expand the universe of diseases that can be treated with gene therapy. This funding also testifies to the growing potential of Barcelona’s biotechnology cluster.

Photo by Flickr user Jorge Franganillo via Creative Commons license