If the deal doesn't renew in 2015, then there is a five year wind down period where Veeva can sell a limited number new licenses but still use the platform. Presumably if this happens, they'll have to rebuild it. It's addressed in the S1.
Interesting thing about Veeva is that unlike every other saas company on earth, they actually have a healthy operating margin despite being in hyper-growth mode. This will close on the first day of trading with a $4.5 billion enterprise value.