The top 15 biopharma M&A mistakes of the last decade

Bayer's Monsanto deal and many others made our report featuring top M&A mistakes from the last decade. (Kritchanut/iStock/Getty Images Plus/Getty Images)

Biopharma companies have spent hundreds of billions of dollars on M&A over the last decade in moves that reshaped the drug industry and together led to thousands of layoffs, manufacturing and lab shutdowns, abandoned R&D programs, and, for some, enormous levels of debt.

Of course, many of those deals helped bring game-changing treatments to market. Gilead Sciences' 2011 Pharmasset deal delivered a suite of hepatitis C drugs that were so successful at curing patients, they shrunk their own market. Others put cash-ginning products in the hands of drugmakers that needed them.

But others weren't so lucky.

In this report, we're featuring 15 deals that didn't work out as the buyers had hoped. The deals fell short for a variety of reasons: failed launches, for instance, or outsized legal problems.

Of course, the purchases also vary in size and in how much their shortfalls pained their buyers. For instance, Bayer's hurting more from its $63 billion Monsanto merger than Merck is suffering from its $8.3 billion Cubist deal.

In all, the list features Bayer's Monsanto deal, Teva's purchase of Allergan's generics, Shire's Baxalta buy and much more. The deals range in size from $63 billion to Valeant's failed $1 billion purchase of Sprout Pharmaceuticals.

This report doesn't include deal proposals that never came together, such as Pfizer's high-profile pursuits of AstraZeneca and Allergan. AbbVie sought to buy Shire but changed its mind after the U.S. government ushered in new tax rules to put a damper on inversions. Instead, AbbVie is now buying Allergan in a bid to shore up its post-Humira future. 

Please click through to read more on biopharma's M&A mistakes of the last decade. If you have any thoughts, please get in touch. — Eric Sagonowsky (email)