In Agile, you are supposed to ship product on a regular cadence. All features are added to a product backlog, divided into small projects that fit within a sprint, and then prioritized. The backlog is just a way to keep track of all of the ideas people have, requests from customers, major bugs and other things.
The first patent for Pristiq is set to expire in February 2022. This is the earliest predictable date that a generic version of the drug could become available. However, other circumstances could come up to extend or shorten the exclusivity period.
The first patent for Intuniv currently expires in September 2015. However, a generic version is expected earlier, in December 2014, as the result of a settlement agreement between Shire (the manufacturer of Intuniv) and Actavis (a generic manufacturer). This is the earliest predictable date that a generic version of Intuniv could become available.