Isis Pharmaceuticals and Alnylam Pharmaceuticals received a patent that lays claim to certain chemical modifications of oligonucleotides, which can be used to introduce drug-like properties in antisense oligonucleotides, including siRNAs. "This newly issued patent broadly covers certain chemical modifications that are used to improve potency, stability, and selectivity of siRNAs, including so-called no-ribose or siNA derivatives," says John Maraganore, Ph.D., president and CEO of Alnylam.
The new patent broadly covers oligonucleotide compositions containing more than one 2'-ribose modifications, such as 2'-O-methyl and 2'-fluoro groups. The Journal of Medicinal Chemistry reported that these chemical modifications can be used to improve potency and stability of siRNAs and can also be used to optimize their selectivity.
The issued patent is owned by Isis and is licensed exclusively to Alnylam for double-stranded RNAi therapeutic applications, according to the terms of a 2004 collaboration and license agreement between the companies.