With last week’s news that pharmaceutical giants Pfizer Inc. and Allergan plc will join together in a tax inversion valued at $160 billion, 2015 appears to be the year of the deal. The transaction brings total M&A value to $3.82 trillion for the year to date—4.3 percent higher than the record set in 2007, according to Mergermarket data.

The combination—the second-largest merger in history after Vodafone’s 1999 purchase of Mannesmann for about $172 billion—could have ramifications around the globe, pushing up drug prices and spurring more such deals in the fast-consolidating health care sector and other fields.