Lantus

5. Lantus
The company: Sanofi
Worldwide sales: $7.59 billion

Sanofi's ($SNY) got the top-selling diabetes drug in the world in a market that's only getting bigger. Sales of Lantus have made leaps and bounds in recent years, swelling by 20% between 2012 and 2013 and by 19.3% the year before that.

That's good news for the French drugmaker, for whom Lantus pulled in 17% of total sales and 21% of pharmaceutical sales last year. The pharma giant has relied on the med to pull it out of patent-cliff struggles, and, more recently, a generics fumble in Brazil that cost the company nearly as much as knockoff competition to two if its biggest drugs in 2013's second quarter.

But that's not to say Sanofi has been sitting idly by as the diabetes patient pool widens. The company caught a huge break when the FDA sidelined would-be rival Tresiba from Novo Nordisk ($NVO), but it has also been aggressively protecting its position at the top.

For one, Sanofi has been pushing hard into emerging markets like China, where it has a strong foothold. It opened a handful of plants there in 2013, in addition to starting on a facility in Vietnam and beginning commercial production at an insulin pen plant in Russia. It has also raised prices on the market-leading Lantus, taking a 10% hike on Lantus vials and SoloSTAR injection pens in April and following up with another boost in August.

Then, there's the successor Sanofi's developing in advance of Lantus' 2015 patent expiration. In a study released in December, the candidate, know as U300, posted a 23% drop in the number of patients suffering from low blood sugar when compared with the Lantus arm.

Most recently, Sanofi used its legal powers to ward off a Lantus challenger from Eli Lilly ($LLY), suing the Indianapolis-based drugmaker over infringement claims on four of the drug's patents. The lawsuit put into play an automatic 30-month stay of approval by the FDA, which will keep Lilly's biosimilar off the U.S. market until mid-2016; if Sanofi wins in court, that protection could be extended.

For more:
Special Report: 10 Top-selling Diabetes Drugs - 2012
Sanofi wards off Lilly's Lantus challenger with infringement lawsuit
Sanofi has Lantus for now but says its successor is looking good
Easing U.S. drug spending gives Sanofi, Novo room to raise insulin prices
Sanofi uses multi-pronged strategy to defend its place in diabetes market

-- Carly Helfand (email | Twitter)

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