The pending Abbvie Inc. merger with Allergan plc, expected to close in the first quarter, brought good tidings to another “A” company on Monday, allowing Astrazeneca plc to regain global rights to its late-stage Crohn’s disease and ulcerative colitis (UC) drug, brazikumab, an anti-IL-23 therapy that was out-licensed to Allergan in a $1.27 billion deal in 2016.