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.
For applications filed before June 8, 1995 and for patents that were still in force on June 8, 1995, the patent term is either 17 years from the issue date or 20 years from the filing date of the earliest U.S. or international (PCT) application to which priority is claimed (excluding provisional applications), the longer term applying.