13. Teva

It was a tough year for Teva, despite nailing down its $40.5 billion deal for Allergan's generics business.

13. Teva Pharmaceutical Industries 
Headquarters: Petah Tikva, Israel
2016 revenues: $21.90 billion
2015 revenues: $20.00 billion 

2016 wasn’t exactly the best year to be Teva. The Israeli generics giant did finally manage to seal its $40.5 billion deal for Allergan’s generics unit in August, though, helping swell generics unit revenues by 13.7% to $11.99 billion. Over five months, the unit chipped in $1.2 billion of that haul, Teva said.

That's not to say investors and analysts loved the deal by the time it eventually closed. Deutsche Bank analysts cut their forecasts for the unit shortly before Teva officially absorbed it, and December's sudden departure of generics CEO Siggi Olafsson—a major champion of the buy—spooked shareholders. 

Generics sales did end up taking a hit in the U.S., decreasing by 5% from 2015’s total. Teva had losses of exclusivity on its generic versions of AstraZeneca’s Nexium and Otsuka’s Abilify to thank for much of the decline, though a dip in generic Pulmicort sales and the divestments Teva made to get the Allergan deal past regulators hurt, too.

Among Teva’s best-selling generics? A pair of ADHD copies: versions of Johnson & Johnson treatment Concerta and Shire’s Adderall XR.

As usual, though, Teva’s multiple sclerosis star Copaxone brought in the lion’s share of revenue—9%, to be exact. The med accounted for $4.2 billion, $3.5 billion of which came in the U.S.

That revenue stream is in grave danger, though, especially after a U.S. District Court this January upturned four patents on the long-acting version of the product. But a recent FDA warning letter may have bought Teva some time before knockoffs hit: Regulators hit Momenta with a manufacturing-focused rebuke, likely delaying an approval of its generic.

Back to 2016, though. Copaxone helped Teva’s specialty unit rake in $8.7 billion, an increase of 4% over 2015. U.S. specialty revenues swelled by the same margin to hit $6.7 billion overall.

2017 is already figuring to be a bit of a rocky year, and CEO Erez Vigodman's February exit did little to change that perception. Whatever happens, though, Teva's leaders say they're committed to preserving their $23.8 billion to $24.5 billion revenue guidance range, which they've already walked back by more than $1 billion.

13. Teva