UPDATE 1-Pfizer-Allergan to take healthcare M&A deals to above $600 bln in 2015 By: Reuters: Company News November 23, 2015 at 14:42 PM EST * Mega-merger may be exception amid bolt-ons, divestments (Adds Breakingviews link) Read More >> Related Stocks: AbbVie Allergan Plc Gsk Plc ADR Merck & Co Pfizer