Advancing translational readthrough therapies: genetic and mechanistic insights in Choroideremia nonsense mutation models

Abstract Nonsense variants account for approximately 11% of rare genetic diseases and represent a severe class of mutations for which effective therapies are still lacking. One promising strategy is suppression therapy using translational readthrough-inducing drugs (TRIDs). In this study, we investigated the mechanisms of action and readthrough activity of three TRIDs, NV848, NV914, and NV930, in models of Choroideremia, an X-linked retinal degenerative disease caused by nonsense mutations in the CHM gene. Using the PURE-LITE cell-free translation system, we assessed their ability to promote readthrough and interfere with release factor–mediated termination, revealing mechanisms distinct from that of PTC124. To evaluate their therapeutic potential in cellular contexts, we developed two engineered Choroideremia nonsense cell models and analyzed REP1 protein rescue in patient-derived primary fibroblasts. All three compounds effectively induced readthrough both in the cell-free system and in cellular models, supporting their potential as candidates for treating nonsense mutation-associated retinal diseases.