I also expect that the royalties will be divided under provisions of the contract with Sandoz. I have asked if we know those terms and not gotten an answer. Best guess is that the royalties get divided just like profits. IF they are NOT divided then I would think Sandoz gets all of the royalties.
Possible - but I doubt that the patent-suit split is just the same as profit just because that would highly disincetivize Momenta both in the suit and leading up to the suit (some of the patents were written well after the agreement with Sandoz was signed). Not something Sandoz would want to do when they too stand to lose from entry of a generic on the market. And I would expect that Momenta would have made exactly this argument when they were negotiating the original agreement.
To say this another way - the whole royalty agreement was clearly designed to very significantly incentivize Momenta to do the right things to protect the franchise. I would expect that something similar occurred with the rewards from a patent suit.