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.
Patent protection usually ends when the patent expires. Here are the expiration dates: For all utility patents filed before June 8, 1995, the patent term is 20 years from date of filing, or 17 years from date of issuance, whichever period is longer.