CRISPR‐Cas9 in Cancer Therapy: Overcoming Delivery Barriers and Off‐Target Effects for Clinical Translation

ABSTRACT Background and Aims CRISPR‐Cas9 gene editing has transformed molecular biology and has great potential as a therapeutic tool for cancer and many other human diseases. This perspective review elaborates on the recent advances in CRISPR‐Cas9 technology and its application as an innovative cancer treatment. Additionally, this perspective outlines the current barriers to clinical translation, including in vivo delivery and off‐target effects, as well as potential mitigation strategies. Discussion CRISPR‐Cas9 has enabled the development of innovative methods to enhance immunotherapy, overcome drug resistance, and identify new therapeutic targets. Importantly, CRISPR‐Cas9‐induced DNA double‐strand breaks can activate p53‐mediated selection and cause unintended on‐target genomic alterations, including large deletions, chromosomal rearrangements, and chromosome loss. While progress has been made toward addressing these significant obstacles, optimizing delivery systems, minimizing off‐target effects, and addressing immunogenicity are critical for the successful clinical application of CRISPR‐Cas9. Emerging strategies, including high‐fidelity Cas9 variants, optimized guide RNAs, and advanced non‐viral delivery systems such as lipid nanoparticles (LNPs) and exosomes, may improve the precision, safety, and delivery of CRISPR‐Cas9‐based therapies. Continued innovation in base editing and prime editing may enable the development of more refined approaches for precise genome modification. Conclusion From a translational perspective, we argue that improvements in editing efficiency alone will be insufficient; clinical success will require the simultaneous achievement of tumor‐selective delivery, genomic integrity, and acceptable long‐term safety. Therefore, the continued development of novel approaches should be promoted to realize the full potential of CRISPR‐Cas9 technology in oncology and other therapeutic applications.