INC Research, a global Phase I–IV CRO, and inVentiv Health, Inc., a privately held, global CRO and Contract Commercial Organization (CCO), have approved a definitive merger agreement to combine in an all-stock transaction that values inVentiv at approximately $4.6 billion, and the combined company at approximately $7.4 billion.   Upon closing, INC Research will own approximately 53% and inVentiv will own approximately 47% of the combined company. The transaction, subject to customary closing c...