Cystic Fibrosis Foundation Commits Up To $13M To SpliSense To Advance Inhaled ASO Therapy

The Cystic Fibrosis Foundation will provide up to $13 million in funding to Israeli biotech SpliSense to support continued development of SPL84, an inhaled antisense oligonucleotide (ASO) designed to treat cystic fibrosis (CF) caused by the 3849+10kb C→T CFTR mutation.

Phase IIa Results and Mechanism

SPL84 targets the splicing defect created by the 3849+10kb C→T mutation and is delivered directly to the lungs via inhalation for focused organ-level exposure. In a Phase IIa study (NCT06429176), SpliSense reported favourable safety and encouraging efficacy signals: up to 70% of treated patients showed improvements in lung function. Some trial cohorts included participants who were already receiving standard-of-care CFTR modulators.

Regulatory Status and Next Steps

SPL84 has received several regulatory incentives: Fast Track and Orphan Drug designations from the US Food and Drug Administration (FDA) and PRIME designation from the European Medicines Agency (EMA), each designed to speed development and review. With the Cystic Fibrosis Foundation's backing secured, SpliSense will continue its randomized, placebo-controlled Phase IIb study, which plans to enrol roughly 40 patients across sites in the US, Europe and Israel. Topline results are expected in the second half of 2027.

Gili Hart, CEO of SpliSense: "We are honoured by the Cystic Fibrosis Foundation's investment, which underscores the strength of our Phase II data and the potential for SPL84 to become a transformative treatment option for patients. This support will also help advance earlier pipeline candidates aimed at other lung diseases into the clinic."

Context And Market

In the United States nearly 40,000 children and adults live with cystic fibrosis, a genetic disease caused by defects in the CFTR gene that lead to thick mucus, recurrent infections and progressive lung damage. Current CFTR modulators are mutation-specific and administered orally; Vertex Pharmaceuticals’ Trikafta (elexacaftor/tezacaftor/ivacaftor) remains the leading therapy in the class, with $10.31 billion in sales in 2025, highlighting the commercial and clinical importance of effective CF therapies.

Earlier this year the Cystic Fibrosis Foundation also announced a research collaboration with Antiverse to develop antibodies targeting the extracellular region of the CFTR protein, underscoring the foundation's broader strategic investments in diverse therapeutic approaches.

Note: Data reported by SpliSense from Phase IIa reflect company disclosures. As with all early-stage results, outcomes will be further validated in larger, controlled studies.