1. Copaxone
2013 Revenue:
$4.33 billion

Teva ($TEVA) got a big surprise last year--the kind every drugmaker dreads--when a court invalidated its patents on top-seller Copaxone. The move bumped up the drug's patent expiration by 18 months, sending the Israeli pharma--which at the time derived more than half its profit from the med--scrambling.

But a couple of key things have gone Teva's way since then. For one, the Supreme Court agreed to hear Teva's appeal, a process that could begin this fall. And two, the FDA approved a new, long-acting version of Copaxone, to which Teva has been converting patients at a rate that's both surprised and impressed analysts.

When all is said and done, the company thinks it can have 65% of patients on the new, patent-protected version of the drug by the end of this year. But that doesn't mean all is rosy over in Petah Tikvah. A decision on Teva's appeal could come as late as next summer, and until then, the company is vulnerable to generic competition. This spring, it tried unsuccessfully to convince SCOTUS to stay Copaxone copies until the case is closed. And its latest attempt to keep any would-be knockoffs at bay: filing a petition with the FDA to push for full-scale, placebo-controlled clinical trials for all Copaxone copies. -- Carly Helfand (email | Twitter)

For more:
Mylan, Momenta, Sandoz join assault on Teva's new-and-improved Copaxone
Teva gets more than half of U.S. Copaxone patients converted to long-lasting version
Teva trots out genetics in new petition against Copaxone copies
Desperate to ward off Copaxone copies, Teva sues FDA