Sanofi steps deeper into RNAi work, opts in on Alnylam hemophilia drug

Genzyme CEO David Meeker

Sanofi ($SNY) cautiously waded deeper into RNAi development waters this week, following up on last year's big $700 million buy-in at Alnylam ($ALNY). The pharma giant's Boston subsidiary, Genzyme Sanofi, has picked up some regional rights to the hemophilia treatment ALN-AT3, setting up a complicated set of next steps as Sanofi juggles just what it will opt into and where it wants to leap into commercialization.

Back at the beginning of 2014 Sanofi spent $700 million to buy into Alnylam, picking up a 12% share of the company as it set out to replicate the kind of close (and bountiful) relationship it has with Regeneron. That deal included opt-in rights and helped put the spotlight back on RNAi, which had fallen out of favor at a number of Big Pharmas, like Novartis ($NVS).

The initial deal gave Sanofi rights to patisiran and revusiran. This third opt-in on the hemophilia program--ALN-AT3 knocks down antithrombin, providing more natural formation of blood clots hemophiliacs need to stop bleeding--started with Sanofi gaining rights to commercialize the drug outside of North America and Western Europe. But it doesn't end there, and dealmakers all over the world might enjoy the details.

In the next step Sanofi can either step in to co-develop the drug for the prime North American and Western European rights, or it can keep the rest-of-world territory and opt in on global rights to a new drug--ALN-AS1--for acute hepatic porphyrias. They get to choose once the ALN-AS1 proof-of-concept study is wrapped up next year.

On any regional pacts it makes, Sanofi will pick up 20% of the development tab. That rises to 50% for co-development deals and 100% when it goes in for global control. There's a similar sliding scale for milestone packages for each drug, rising from $75 million to $200 million for worldwide rights. And there's a hefty royalty package that goes up to 20% for Alnylam, unless they're using a simple revenue splitting formula on a drug.

"ALN-AT3 represents a unique and promising new approach for the potential treatment of hemophilia," said David Meeker, the CEO of Genzyme.

- here's the release