In 2010, $16.5 billion was spent on breast cancer treatment in the U.S. and as much as $25 billion could be spent treating the disease by 2010, according to the National Cancer Institute. Additionally, the World Health Organization reports that 1.4 million new cases are diagnosed each year and that more than 450,000 die annually from the cancer.

That means there's a significant and growing need for new and better treatments for this significant and important disease. Fortunately, three companies are working on intriguing new compounds that may offer new hope for patients.

Pfizer (NYSE:PFE), Novartis (NYSE:NVS), and Eli Lilly (NYSE:LLY)are developing new drugs that target a specific enzyme known as CDK 4/6. So far, Pfizer's palbociclib is the closest to reaching the market, but Novartis and Lilly aren't far behind it.

In the following slideshow, you'll learn more about Pfizer, Novartis, and Lilly's drugs and how they may help breast cancer patients in the future.