It is very difficult to estimate how many mergers and acquisitions in the pharmaceutical industry have succeeded. It is even more difficult to define what success means. K. Sreekanth Reddy, V. Balamuralidhara, Shilpi Khattri and T. M. Pramod Kumar of JSS College of Pharmacy, JSS University, Mysore look into the challenges of corporate takeovers, showing us why 80% of mergers do not meet their pre-merger financial goals and 50% become failures.
https://international-pharma.com/wp-content/uploads/2014/07/Merging.pdf