Spain’s SpliceBio Secures $135M Series B to Advance AAV Gene Therapy Pipeline, Led by Sanofi and Roche

BARCELONA, SPAIN, 11 June 2025-  SpliceBio, a Spanish biotech company, has successfully closed a $135 million Series B funding round, with significant backing from pharmaceutical giants Sanofi and Roche. The substantial capital infusion will primarily fuel the clinical advancement of its lead adeno-associated viral (AAV) gene editing therapy, SB-007, for Stargardt disease.

Stargardt disease, a genetic disorder causing vision loss in both children and adults, is the target of SpliceBio’s cutting-edge AAV SB-007. This specific gene therapy is already undergoing a Phase 1/2 clinical trial for the indication, showcasing the company’s progress with its AAV-based approaches.

The Series B round was co-led by new investors EQT Life Sciences and Sanofi Ventures, and saw strong support from existing investors including Roche Venture Fund, New Enterprise Associates, UCB Ventures, Ysios Capital, Gilde Healthcare, Novartis Venture Fund, and Asabys Partners. The broad investor base underscores confidence in SpliceBio’s AAV gene therapy platform.

Beyond funding the ongoing Phase 1/2 study of SB-007, which is designed to produce a functional copy of the full-length ABCA4 protein via an AAV vector, SpliceBio intends to use the proceeds to “accelerate” the development of its broader pipeline of gene therapy programs. These innovative AAV programs span ophthalmology, neurology, and other undisclosed indications, demonstrating the wide applicability of their technology.

“This financing marks a pivotal milestone for SpliceBio as we advance the clinical development of SB-007 for Stargardt disease and continue to expand our pipeline across ophthalmology, neurology and beyond,” stated Miquel Vila-Perelló, Ph.D., CEO of SpliceBio, in a June 11 release. “The support from such high-quality investors underscores the strength of our AAV programs and our unique Protein Splicing platform and its potential to unlock gene therapies for diseases that remain untreatable today,” Vila-Perelló added, emphasizing the transformative power of their AAV-driven approach. “We are building a company positioned to lead the next wave of genetic medicines through advanced AAV delivery.”

Roche’s Spark Therapeutics unit previously penned a $126 million alliance with SpliceBio back in 2023. This collaboration specifically leverages SpliceBio’s platform, which aims to sidestep a common challenge in AAV gene therapy: where the necessary gene is too large to fit efficiently within traditional AAV vectors. This highlights SpliceBio’s innovative solutions in overcoming delivery limitations.

In this morning’s release, Carole Nuechterlein, head of Roche Venture Fund, said the fund had been “impressed by the momentum behind SB-007 in Stargardt disease, and the platform’s potential to unlock a new class of genetic medicines,” underscoring the strong belief in SpliceBio’s AAV gene therapy capabilities.

SpliceBio emerged in 2022 with 50 million euros ($57 million) to tackle delivery barriers in gene therapy, backed by UCB Ventures and the Novartis Venture Fund. The biotech’s work, focused on improving AAV delivery, is based on technology developed in the Muir Lab at Princeton University.