Regulus Deal Makes GSK Clear Force in MicroRNA Therapeutics

Only months after closing a similar agreement for the development of antiviral microRNA therapeutics with LNA company Santaris (Santaris PR), GSK today agreed to a co-development partnership with the Alnylam-ISIS microRNA therapeutics joint venture Regulus Therapeutics in the inflammatory disease area (Regulus PR).

In both deals, GSK has the option to select up to 4 microRNA therapeutics candidates developed by Santaris or Regulus in the respective disease areas for comparable financial terms that gives the microRNA therapeutics companies important and largely undilutive upfront cash, development milestones, and royalties (for exact terms, please refer to the Santaris and Reguls PRs).

It is also a vote of confidence by Big Pharma that it sees microRNA therapeutics as a significant new emerging treatment modality. While the antiviral programs with Santaris should be based on the straight-forward targeting of either viral or host microRNAs directly implicated in viral infection, the anti-inflammatory programs with Regulus may be based on more complex microRNA pathway biology.

Interestingly, in both cases the emphasis is on microRNAs as targets for antisense antagonists and much of the discussion in today’s conference call on Regulus’ general microRNA therapeutics activities centered on such antagonist approaches, although I previously was under the impression that microRNA agonist approaches would also fall within the scope of Regulus.

Actually, when I woke up this morning and saw the headlines, I thought that the GSK-Regulus alliance would relate to a mystery surrounding microRNA-122 in HCV replication that is currently being developed by both Santaris and Regulus. Since miR-122 is by far the most advanced antiviral microRNA therapeutics candidate program, it is no stretch of the imagination that GSK will exercise their rights to Santaris’ HCV program that, in collaboration with the Sarnow lab, was subject to a recent high-profile publication in Nature. The issue here is that the Sarnow patents for targeting miR-122 in HCV from Stanford were exclusively licensed to Alnylam (now part of Regulus IP) and GSK-Santaris would therefore ultimately need access to this important patent. A Regulus-Santaris collaboration, however, is complicated by the fact that this program pits ISIS’ against Santaris’ LNA antisense chemistries. It is hoped that miR-122 will eventually aid in synergizing microRNA therapeutics efforts rather than leading to a Merck-like situation where GSK would end up in mutually exclusive collaborations. This issue probably should be addressed early on before it may cause harm down the line.