Factbox: Who is next in big pharma's merger spree?

(Reuters) - Consolidation in the U.S. healthcare industry, which has already witnessed a string of multi-billion dollar deals, is expected to remain a major theme for the rest of 2019. Bristol-Myers Squibb's $74 billion (£60.9 billion) acquisition of Celgene set the M&A ball rolling in January, and was followed by AbbVie Inc's $63 billion bid for troubled smaller rival Allergan Plc .Regulators are pressuring companies to cut drug costs and takeovers have become the preferred method of..