Restoring chloride efflux in cystic fibrosis with TMEM16a antisense oligonucleotides.

Patients with cystic fibrosis (CF) who are non-responsive to treatments due to specific mutations need alternative CF transmembrane conductance regulator (CFTR)-independent therapies. This study aims to assess the impact of TMEM16a expression by a specific oligonucleotide (TMEM16a ASO) on dysregulated parameters in CF, which will help prepare for preclinical studies. In this study, we analyzed the effects of TMEM16a oligonucleotide within a CF context by evaluating the impact, optimal administration route, toxicity, and specificity in primary cells and various mouse models. The oligonucleotide enhances TMEM16a activity, increases Cl- efflux, and improves mucociliary clearance in cells from all individuals tested with CF. The TMEM16a antisense oligonucleotide (ASO) effect is detectable in mice 30 days after subcutaneous injection, enhances TMEM16a mRNA expression, and significantly extends the lifespan of CF mice. Acute administration of 50 times the effective dose showed no toxicity. Importantly, TMEM16a ASO is highly specific, not inducing inflammation or altering intracellular calcium mobilization and cell proliferation, instilling confidence in its potential effectiveness. Our study demonstrates that TMEM16a ASO can compensate for CFTR deficiency in CF models. Additionally, it is important to note that this strategy could apply to all CF patients, regardless of their CFTR mutation, thereby broadening the scope of treatment options for CF.