Every year, the promise of safer and more effective drugs coming to market gives an aging population hope. According to the Phrma organization's website, roughly $49 billion was spent on researching some 2,900 compounds last year alone. The truly amazing part is that we've only touched the tip of the iceberg on what diseases are left to be researched and/or cured. We still have a long way to go with regards to cancer research, and many rare diseases still have largely unmet needs.

Each week for a total of five weeks, I'm going to look at an upcoming drug that has every indication of being not only a revenue blockbuster, but a true life changer. Keep in mind that none of the five drug hopefuls I'll be highlighting are approved by the Food and Drug Administration, so there are plenty of obstacles left to be encountered, including safety data, which could still stand in the way of an ultimate approval.

 In the previous three parts of this five part series I've highlighted three game-changing drugs:

This week, I want to take a closer look at an experimental blood-thinner called Eliquis, developed jointly by Bristol-Myers Squibb (BMY 1.30%) and Pfizer (PFE 2.40%).

Both drug makers are in dire need of a blockbuster drug after seeing their two blockbusters (and previously the No. 2 and No. 1 best-selling drugs in the world, respectively) Plavix and Lipitor go off patent. Even more than Pfizer, Bristol-Myers needs a bit of good news after purchasing Inhibitex for $2.5 billion, only to write down $1.8 billion of its purchase because the hepatitis-C compound it wanted to get its hands on wasn't found safe in clinical trials. May I add, this all occurred shortly after Gilead Sciences acquired sofosbuvir by purchasing Pharmasset; and as we saw in part 2 of this series, sofosbuvir is a blockbuster in the making.

That blockbuster just might come in the form of Eliquis, a blood-thinning agent designed to prevent strokes and systemic embolism in patients with heart-rhythm problems. Eliquis is already approved in Europe for the prevention of strokes for those patients with atrial fibrillation, as well as for the prevention of blood clots in patients who have undergone hip or knee replacement surgeries.

Unfortunately, Eliquis is still waiting to get approval in the United States; the decision regarding this experimental blood thinner's approval for the prevention of strokes and systemic embolism in patients with non-valvular atrial fibrillation was delayed by the FDA this summer. These delays have allowed competing drugs like Pradaxa from Boehringer Ingelheim -- which was recently found to be just as safe as Warfarin despite deaths being associated with the drug  -- and Xarelto from Johnson & Johnson (JNJ 1.49%) and Bayer (BAYR.Y 0.57%) to get to market before Eliquis.

Yet data from Bristol-Myers and Pfizer's Aristotle study showed that Eliquis was a far superior anticoagulant from an efficacy and safety perspective than Warfarin, the most commonly prescribed anticoagulant. Relative to Warfarin in a 1.8 year study of 18,201 patients, patients on Eliquis had fewer strokes or systemic embolisms, less major bleeding, fewer hemorrhagic strokes, and fewer deaths during trial relative to Warfarin.

The market for Eliquis is huge: 6 million people in the U.S. and an additional 6 million people in Europe suffer from atrial fibrillation, according to FiercePharma. The drug itself could have the potential for up to $3 billion to $5 billion in peak annual sales if approved. More importantly, if these large tests have proven accurate (and we have a European approval to confirm this), Eliquis appears to be a superior and safe option to many existing treatments already on the market, and is set to make millions of people's lives better.

Be sure to check back next week when I unveil the fifth and final pipeline drug capable of changing your life for the better.