The drug: Herceptin
The company: Roche
Estimated worldwide sales 2012: $6.08 billion

Herceptin has long been the dominant breast cancer drug on the market. And Roche ($RHHBY) has been steadily building sales around the world. In a recent report, Decision Resources noted that overall the entire category for breast cancer therapies is likely to rise significantly for another 6 years. And with patent expiration coming in 2014 for Europe and 2018 or 2019 for the U.S.--which will open the way for biosimilars now in development--Roche has a limited window open to capitalize on the opportunity.

New Herceptin data came to light at the European Society of Medical Oncology meeting in October. On the bright side for Roche, a French study failed to show that 6 months of Herceptin therapy after surgery was as effective as the current one-year treatment standard. Positive data on that score would have eaten into sales significantly.

On the other hand, its own HERA study showed that continuing Herceptin treatment for two years after surgery wasn't significantly better than one year of treatment. So don't look for dramatic increases in use next year.

Still, Roche is looking at an increase in sales, from $4.8 billion in 2011.

For more:
Herceptin data fends off $1.5B threat to Roche sales
T-DM1 survival rate wows as Roche pushes for megablockbuster approval
When Herceptin gets under the skin--literally
Cancer drugs lift Roche sales as charges slash earnings