Copaxone (glatiramer acetate injection)
Company: Teva
Disease: Multiple sclerosis
Global 2013 sales: $4.33 billion
U.S. patent expiration date: September 2015

Copaxone's patent expiration date has been causing some serious consternation at Teva ($TEVA) for a while now. Last July, a U.S. court upturned the Israeli company's protection on its top-selling drug, bumping up the patent deadline by 16 months to May 2014.

With more than half the company's profits in jeopardy, layoffs, labor protests, a CEO exit and shareholder discontent followed. Teva's been working to get things back on track ever since, and key to that effort has been FDA approval for a new, long-acting version of the multiple sclerosis blockbuster.

The agency gave the 40-mg formulation the green light in January, and the Petah Tikva-based drugmaker has been racing to convert patients ever since. So far, it's surpassed analysts' expectations, with ISI Group analysts reporting in October that close to 60% of patients had already made the switch.

But that doesn't mean the company has nothing to lose if generics hit. Though the Supreme Court has already heard oral arguments in Teva's patent case, a decision might not come down till next summer. And that could be "effectively too late to prevent irreparable harm to Teva," the company's lawyers wrote in an April court filing.

As of now, though, Copaxone's sales are intact. Generics teams of Mylan ($MYL) and India's Natco Pharma, and Novartis' ($NVS) Sandoz and Momenta Pharmaceuticals ($MNTA) haven't yet launched their copies. If they do, they face the possibility of paying reparations if SCOTUS sides with Teva.

For more:
If Teva wanted a clear sign from Supreme Court on Copaxone, no such luck
Corks are a-popping at Teva with FDA nod for its new Copaxone formula
U.S. court upturns Teva's patents on cash-cow Copaxone

-- Carly Helfand (email | Twitter)