SpliceBio Secures $135 Million Series B Funding to Advance Protein Splicing Technology

Barcelona-based genetic medicines company SpliceBio has successfully raised $135 million in a Series B funding round, marking a significant milestone in the development of its innovative protein-splicing drug delivery system. The funding will primarily support the advancement of the company's lead gene therapy candidate for Stargardt disease, a rare inherited form of macular degeneration.

Novel Intein-Based Technology Tackles Gene Size Limitations

SpliceBio's groundbreaking approach addresses a critical challenge in gene therapy: delivering large genes that exceed the capacity of traditional adeno-associated viral (AAV) vectors. The company's technology, which focuses on protein splicing rather than gene splicing or editing, offers a unique solution for genes like ABCA4, implicated in Stargardt disease.

"It's like putting together the pieces of a puzzle," explained Miquel Vila-Perelló, CEO of SpliceBio. The company's lead gene therapy, SB-007, splits the ABCA4 gene into two parts, each delivered by a separate AAV vector. These gene fragments are then translated independently before being spliced together by engineered intein sequences to form the complete, functional protein.

Clinical Progress and Strategic Focus on Ophthalmology

SpliceBio has made significant strides in bringing its technology to the clinic. In March, the company dosed its first patient in the Phase I/II ASTRA trial for SB-007. The trial is currently in a dose escalation phase, with the Series B funding set to support its continuation.

The choice to target Stargardt disease is strategic, leveraging the eye's relative immune privilege. This approach allows for a substantially lower dosage of AAVs compared to therapies targeting other parts of the body, potentially enhancing the safety profile of the treatment.

"We have shown that [the company's intein technology] does indeed work in multiple diseases and multiple organs," Vila-Perelló stated, hinting at the broader potential of SpliceBio's platform beyond ophthalmology.

Investor Confidence and Future Prospects

The substantial Series B round, which follows a $57 million Series A in 2022, demonstrates strong investor confidence in SpliceBio's technology. Notably, the funding round saw participation from the venture capital arms of major pharmaceutical companies, including Novartis, Sanofi, and Roche.

While SpliceBio's immediate focus remains on advancing SB-007 for Stargardt disease, the company is also developing molecules for undisclosed indications, showcasing the versatility of its intein-based platform. As SpliceBio continues to progress its pipeline, the pharmaceutical industry will be watching closely to see if this innovative approach can overcome long-standing challenges in gene therapy delivery.