Any agreement on the licensing of the patents that does not reflect the profit sharing terms, incents one party to act in their own interest against their partner.
1) The existing terms clearly already incentivize a division of interests - as I noted long ago. E.g. in an extreme instance Momenta is clearly incentivized to take up front licensing cash vs royalties of any form if they get the nice split now - but get reamed on royalties. But similar division of interests exists even related to the way that the triggers in royalties trip.
2) The existing terms are clearly about preventing the entrance of another generic (i.e. secrecy) - something that patents are poorly designed to do per the licensing terms in the contract (e.g. the recent triggering of move to hybrid was a hair trigger - something the patents would have a hard time preventing). I would expect defense of the patents (including creating them) to be differently incentivized.
All that said, I am not so extreme as Dew in thinking that nothing will accrue to Sandoz except the duration of exclusivity. It MIGHT happen that way - but my confidence in that outcome is not Dew's apparent 90+ percent.
PS Clearly Momenta is soon going to have to disclose any prior agreements on this topic - since it is almost certainly material at this point.