Individualized Antisense Oligonucleotide Therapies: How to Approach the Challenge of Manufacturing These Oligos from a Chemistry, Manufacturing, and Control-Regulatory Standpoint.

With the development of antisense oligonucleotides over more than 30 years and the increasing number of identified unique severely debilitating or life-threatening diseases affecting only 1 person in the world-now referred to as N-of-1 diseases-it is more and more appealing to use antisense technology to treat N-of-1 diseases when they are caused by well-identified mutations in single genes. N-of-1 patients present unique challenges to the health care system because the patient may be, and often is, the single patient in the world with the specific mutation in question, thus requiring an approach particular to that patient. Yet, we now know that there are millions of such patients, requiring scalable solutions.

Inhibition of hepatitis B virus replication in vivo using lipoplexes containing altritol-modified antiviral siRNAs.

Chronic infection with the hepatitis B virus (HBV) occurs in approximately 6% of the world's population and carriers of the virus are at risk for complicating hepatocellular carcinoma. Current treatment options have limited efficacy and chronic HBV infection is likely to remain a significant global medical problem for many years to come. Silencing HBV gene expression by harnessing RNA interference (RNAi) presents an attractive option for development of novel and effective anti HBV agents.

Allele-selective inhibition of mutant huntingtin expression with antisense oligonucleotides targeting the expanded CAG repeat.

Huntington's disease (HD) is a currently incurable neurodegenerative disease caused by the expansion of a CAG trinucleotide repeat within the huntingtin (HTT) gene. Therapeutic approaches include selectively inhibiting the expression of the mutated HTT allele while conserving function of the normal allele. We have evaluated a series of antisense oligonucleotides (ASOs) targeted to the expanded CAG repeat within HTT mRNA for their ability to selectively inhibit expression of mutant HTT protein.

Oligodeoxynucleotides containing N1-methyl-2'-deoxyadenosine and N6-methyl-2'-deoxyadenosine.

This unit describes a simple and efficient synthesis of the phosphoramidite derivative of N(1)-methyl-2'-deoxyadenosine from 2'-deoxyadenosine. The synthesis starts with the monomethoxytritylation of 2'-deoxyadenosine followed by methylation of 5'-O-protected nucleoside at N-1. Subsequent N-chloroacetylation leads to N(6)-chloroacetyl-N(1)-methyl-5'-O-(p-anisyldiphenylmethyl)-2'-deoxyadenosine, which is finally converted to its 3' phosphoramidite derivative.

Local RNA target structure influences siRNA efficacy: a systematic global analysis.

The efficiency with which small interfering RNAs (siRNAs) down-regulate specific gene expression in living cells is variable and a number of sequence-governed, biochemical parameters of the siRNA duplex have been proposed for the design of an efficient siRNA. Some of these parameters have been clearly identified to influence the assembly of the RNA-induced silencing complex (RISC), or to favour the sequence preferences of the RISC endonuclease. For other parameters, it is difficult to ascertain whether the influence is a determinant of the siRNA per se, or a determinant of the target RNA, especially its local structural characteristics.