A recent Kilpatrick Townsend presentation on pharmaceutical patent law included these key takeaways on double patenting: -

No recapture of double patenting safe harbor after issue: In In re Janssen Biotech, Inc., the Federal Circuit stated that to receive the 35 U.S.C. § 121 protection from an obviousness-type double patenting (ODP) rejection based on a related application, a patent application had to be designated as a divisional before issue.