I just wanted to post this video by KENS 5 on the anti-miR122 studies in HCV-infected chimpanzees by Danish LNA company Santaris and researchers from the San Antonio Southwest Foundation for Biomedical Research. The study, just published online in Science, shows surprisingly potent reduction of HCV levels (2 1/2 logs) with an miR-122 antisense inhibitor and, at least equally important, without the emergence of viral escape mutants. While this study only involved four chimpanzees and human studies are still in the early phases (phase I, healthy volunteers), these results justify hopes that such a first-in-class agent could be a valuable component of future combination therapies with increased cure-rates, shortened treatment times, and maybe without the need for current standard-of-care component ribavirin.
Curiously in light of these promising results, it appears as if GSK let an option to the Santaris compound expire. While Big Pharma may have multiple reasons why it does not want to pursue a certain compound aside from the science (e.g. the fact that HDL-cholesterol was lowered as a result of miR-122 inhibition could warrant caution), for example product portfolio considerations, one possibility is that IP concerns and GSK's relationship with Regulus were important factors: Regulus has an exclusive license to the IP surrounding the fundamental work by Jopling and Sarnow on the role of miR-122 in HCV replication. While this may be good news for Regulus, I was made aware that the broad Esau and Tuschl patent applications on microRNAs as therapeutic targets and held by Regulus are being narrowed down considerably by the patent offices.
Note: For a more detailed discussion of this paper, please read the review by Mark Kay and myself in Molecular Therapy (click here).
