In its first major announcement as a public company, Alnylam Pharmaceuticals said this week that it has struck another multi-year RNAi-based drug deal with Merck. While not the first partnership between big pharma and an RNAi therapeutics firm — that was a Merck-Alnylam deal signed last year — the collaboration is unique in that it calls for the Merck to take an active role in the RNAi drug development process right off the bat.