SpliceBio Raises $135 Million in Series B to Advance Gene Therapy for Stargardt Disease

SpliceBio has announced the successful closing of a $135 million Series B financing round to accelerate the clinical development of SB-007, the company’s lead gene therapy candidate for Stargardt disease. This inherited retinal condition, caused by mutations in the ABCA4 gene, currently has no approved treatments.

SB-007: Dual AAV Gene Therapy Candidate for Stargardt Disease

SB-007 is the first dual adeno-associated viral (AAV) gene therapy for Stargardt disease to receive FDA clearance for clinical development. It has also been approved by the UK’s Medicines and Healthcare products Regulatory Agency (MHRA). The therapy leverages SpliceBio’s proprietary Protein Splicing platform to deliver a full-length, functional ABCA4 protein, overcoming the gene size limitations inherent to conventional AAV systems.

Clinical Development Progress: ASTRA and POLARIS Studies

SpliceBio is currently conducting two studies in support of SB-007:

       • ASTRA: An interventional Phase 1/2 clinical trial

       • POLARIS: An observational study designed to provide complementary clinical insights

These studies represent a major step forward in the potential treatment of Stargardt disease, addressing an area of high unmet need in retinal genetics.

Series B Funding and Platform Development Update

The Series B round was co-led by EQT Life Sciences and Sanofi Ventures, and included participation from Roche Venture Fund, along with returning investors: 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.”

Proprietary Protein Splicing Platform: Solving AAV Size Limitations

SpliceBio’s Protein Splicing technology is designed to overcome the 4.7 kilobase payload constraint of AAV vectors—a major barrier in gene therapy. The approach involves splitting large genes into multiple segments, each delivered by separate AAV vectors. Once inside the cell, engineered inteins (originally developed at Princeton University) reassemble the fragments into a full-length, functional protein.

This platform not only enables the treatment of Stargardt disease but also opens the door to gene therapy applications for other large-gene conditions.

Pipeline Expansion into Additional Therapeutic Areas

In addition to SB-007, the proceeds from the Series B financing will support the advancement of SpliceBio’s broader pipeline, targeting additional ophthalmologic, neurologic, and undisclosed indications.