Regulus Therapeutics Inc. has not yet put anything in the clinic from its microRNA discovery platform, but it has translated the technology's potential into a pair of lucrative deals with pharma partners before reaching its third birthday.

Two years after signing a discovery deal with a potential value of more than $500 million with GlaxoSmithKline plc, Regulus last week entered a partnership with sanofi-aventis Group that could turn out to be even bigger. The biotech thinks it has the bandwidth to do another deal or two over the next couple of years, but recognizes the importance of ring-fencing a few programs to build its own business.