High-throughput screening discovers arginine-depleted peptides for improved DMD antisense therapy delivery
Researchers used high-throughput screening of over 15,000 synthetic peptides to discover new cell-penetrating peptides (CPPs) with reduced arginine content that can deliver antisense therapeutics more effectively to muscle tissue in Duchenne muscular dystrophy. Conventional arginine-rich CPPs cause dose-limiting toxicity including renal damage, limiting their clinical use. The lead candidate, CXP1, showed ~10-fold lower toxicity than standard CPPs while achieving superior exon-skipping activity in mouse models, potentially enabling more effective DMD treatment with lower doses.
Researchers developed a charge-based chromatographic enrichment platform to screen over 15,000 synthetic peptides, including those with noncanonical amino acids, to identify improved cell-penetrating peptides for delivering antisense therapeutics to muscle tissue. Current approved PMO-based exon-skipping treatments for DMD suffer from poor muscle uptake and require frequent high-dose administration, with conventional arginine-rich CPPs causing significant toxicity including renal damage. Four lead candidates demonstrated efficient nuclear PMO delivery with substantially lower toxicity than standard CPPs like penetratin. The top candidate, CXP1, showed robust splice-switching activity in cellular and animal models, with CXP1-PMO conjugates achieving greater exon skipping than standard R6G-PMO conjugates at equivalent doses in dystrophic mdx mice. Tissue levels of CXP1-PMO correlated directly with exon-skipping efficacy, establishing a clear pharmacokinetic-pharmacodynamic relationship that supports clinical translation.
What's missing
The study's own limitations and open questions are not detailed in the abstract provided. Typical considerations for such work would include: whether findings in mdx mice will translate to human DMD patients; long-term safety and tolerability data; manufacturing scalability of the novel peptides; and whether the approach generalizes to other neuromuscular disorders beyond DMD.
What different sources said
- bioRxivCenter
High-throughput discovery of arginine-depleted peptides enables effective antisense delivery for Duchenne muscular dystrophy
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