SPL23

SPL23 (also known as SPL23-2) is an inhaled antisense oligonucleotide (ASO) developed by SpliSense for the treatment of cystic fibrosis (CF) in patients carrying the W1282X nonsense mutation. The drug works by binding to the CFTR pre-mRNA and inducing the skipping of exon 23. This mechanism bypasses the premature termination codon introduced by the W1282X mutation and prevents nonsense-mediated mRNA decay (NMD), thereby allowing the production of a shortened but functional CFTR protein. This approach is particularly significant for CF patients who do not produce functional CFTR protein and are ineligible for current CFTR modulator therapies.