The Roche deal was interesting. A pessimist would say that Roche just wanted to dump it and its worthless.
There appeared to be some synergy to the deal since ARWR was focused on RNAi delivery before acquiring the Roche assets. If Roche was parring their RNAi assets due to a simple business realignment this would have been an exciting event for ARWR. Unfortunately the best in the industry have hit a dead-end with RNAi delivery so this appears to be a write off of a failed program as opposed to a change in focus for Roche.
I think its because they are very early stage and that is why the deals are all backended.
The backended structure is secondary to what appears to be loose access at an early stage to their acquired IP. ARWR picked up these assets cheaply yet large pharma appears to have worked an even better deal under these terms. This could go either way for ARWR but I'm sceptical of there being value here.
Things like their obesity drug are even earlier then they seem (I think only a monthly injection is viable and they only mentioned that in passing
You astutely questioned the potential market for a sub-q obesity drug. I'm getting drawn too far into this discussion about a company which I lack prior knowledge of or interest in.