**5. Summary and conclusion**

In summary the antisense oligonucleotides are short, synthetic, single-stranded oligodeoxynucleotides that can alter RNA and reduce, restore, or modify protein expression through several distinct mechanisms by targeting the source of the pathogenesis; antisense-mediated therapies have a higher chance of success than therapies targeting downstream pathways. The advancement in the understanding of antisense pharmacology has provided new energy to translate these therapeutics into the clinic. Further advancement of antisense technology in the clinical settings requires more optimization of antisense delivery, target engagement, and safety profile. This technology holds the potential to change the therapeutic landscape for many disease conditions in near future. Most recently, the first gene therapy-based product, Gendicine (Ad-p53), got approved to treat head and neck squamous cell carcinoma in combination with radiotherapy. Also, the drug, Vitravene (known as fomivirsen), was approved for cytomegalovirus retinitis, Macugen (known as pegaptanib) for age-related macular degeneration, Kynamro (known as mipomersen) for homozygous familial hypercholesterolemia, Exondys 51 (known as eteplirsen) for Duchenne muscular dystrophy, Defitelio (known as defibrotide) for severe hepatic veno-occlusive disease, and Spinraza (known as nusinersen) for spinal muscular atrophy by the FDA. The development of antisense therapeutics has now become a clinical reality. The true advancement in the antisense design, chemistries, synthesis, and delivery technologies has been made for adequate stability, efficacy, specificity, and immune evasion. Finally, antisense technology is beginning to bear fruit.
