Israel-based SpliSense announced a funding agreement with the Cystic Fibrosis Foundation under which the Foundation will provide up to USD 13 million to advance the Phase IIb clinical development of SPL84, its inhaled antisense oligonucleotide therapy for cystic fibrosis. The capital is directed at a patient subpopulation carrying the 3849+10kb C→T mutation who continue to have unmet need despite access to approved CFTR modulators — a group for which no targeted therapy currently exists. The funding follows positive Phase II results reported in September 2025 showing lung function improvement in up to 70% of SPL84-treated participants and an estimated mean absolute improvement of 10 percentage points in ppFEV1 versus placebo.
The agreement is structured as a philanthropic funding arrangement with The Cystic Fibrosis Foundation as the sole funder, with no dilutive securities, interest obligations, or repayment terms disclosed. The Foundation has a prior funding relationship with SpliSense, having previously provided up to USD 8.5 million to support the Phase II initiation of SPL84 in April 2024, making this its fourth known investment in the program.
SpliSense is a clinical-stage biotechnology company headquartered in Jerusalem developing antisense oligonucleotide-based therapies for pulmonary diseases. Its proprietary inhaled ASO platform is designed to modulate RNA processing and gene expression directly in the lungs via inhalation, enabling targeted delivery to the primary site of disease.
Its lead asset, SPL84, is an inhaled ASO designed to correct the splicing defect caused by the 3849+10kb C→T mutation in the CFTR gene. By binding to mutant CFTR RNA, SPL84 promotes production of functional CFTR protein. The therapy is administered weekly by inhalation. SPL84 holds FDA Fast Track and Orphan Drug designations, and in March 2026 received EMA Early PRIME designation, recognizing remaining unmet need and supportive clinical data in this mutation subgroup.
The ongoing Phase IIb study is a randomized, placebo-controlled trial evaluating the safety, tolerability, and efficacy of SPL84 in patients carrying the 3849+10kb C→T mutation who are receiving standard-of-care CFTR modulators. The study is expected to enroll approximately 40 participants across sites in the US, Europe, and Israel, with topline results anticipated in H2 2027. Management has explicitly linked the current CFF funding to supporting this trial through to data readout.
Beyond SPL84, SpliSense is advancing two earlier-stage programs: SPL5AC, targeting MUC5AC expression for muco-obstructive diseases including COPD, non-cystic fibrosis bronchiectasis, asthma, and CF; and SPL5B, targeting MUC5B expression for idiopathic pulmonary fibrosis. Both are expected to enter the clinic, with first-in-human studies previously guided for 2026. The company's investors include OrbiMed, Israel Biotech Fund, Integra Holdings, and Biotel Limited, alongside the Cystic Fibrosis Foundation.