Source: MannKind.

MannKind (MNKD 2.45%) shareholders have had quite the year. After more than doubling in the first half of the year, shares have since given back all of their gains and sit essentially unchanged.

Despite the stalemate, MannKind could be on the precipice of incredible growth. With inhaled diabetes drug Afrezza now approved by the Food and Drug Administration and slated to hit pharmacy shelves in the first quarter of 2015, MannKind will soon have revenue flowing in. Additionally, MannKind's licensing partnership with Sanofi (SNY 2.00%) for Afrezza provided it with $150 million in upfront cash and $175 million in collaborative expense fees, essentially eliminating its immediate cash crunch.

Current Wall Street projections have MannKind growing from no product revenue in 2013 to $316 million in revenue by 2017. Furthermore, its reported loss of $0.64 per share in 2013 should improve to a small profit of $0.06 per share by 2017. That's a 109% turnaround in a pretty short time frame.

However, there are three other companies in the drug development space that are actually poised to grow faster than MannKind through 2017. Let's take a closer look at these companies.

1. Alexion Pharmaceuticals (ALXN)
While it's veritably impossible to find a company with a revenue growth rate as fast as MannKind's -- even though starting from zero in sales gives MannKind quite the advantage -- Alexion Pharmaceuticals' EPS growth through 2017 trounces MannKind's estimated 109% improvement.

At the moment, Alexion's success rides entirely on the shoulders of Soliris, an orphan drug designed to treat a rare blood disorder known as paroxysmal nocturnal hemoglobinuria, as well as an ultra-rare genetic disorder known as atypical hemolytic uremic syndrome.


Source: Alexion Pharmaceuticals.

Soliris holds two unique advantages for Alexion and its shareholders. First, as an orphan drug, it's protected against competing drugs. Most ultra-rare diseases probably aren't going to be competitive to begin with, but it provides an added layer of safety that means Soliris is the go-to drug for PNH and aHUS for the near future.

Secondly, Soliris is the most expensive drug in the world, with an annual cost per patient of $536,629! With no alternatives for PNH patients, Soliris is locked in as an approved treatment of choice -- and best of all, most PNH patients will wind up taking the drug for 10-15 years! This means predictably strong cash flow for Alexion. 

Alexion is also looking into further expanding Soliris' indications in four other clinical studies at present.

Having earned $3.08 in EPS in 2013, Alexion's estimated EPS will nearly triple to $9.05 by 2017!

2. Acorda Therapeutics (ACOR)
Next up we have Acorda Therapeutics, a company focused on developing therapies to treat central nervous system disorders.

Source: Acorda Therapeutics.

Although Acorda has three FDA-approved drugs -- Ampyra for walking improvement in multiple sclerosis patients; Zanaflex for spasticity; and Qutenza for post-shingles nerve pain -- Ampyra is without question the workhorse drug generating big profits for Acorda.

In the third quarter, Acorda reported that Ampyra sales rocketed higher by 24% year over year to $96.4 million. Considering that multiple sclerosis is a chronic condition with no cure, it's very reasonable to assume Acorda's drug has quite a bit of shelf-life still ahead of it.  

In addition, Acorda has six other drugs in its pipeline currently in clinical trials, including CVT-301, a late-stage Parkinson's disease that could make it to market by 2017 if approved. CVT-301 is an inhaled version of oral levodopa, the current standard of care for Parkinson's disease. Dalframpridine (the scientific name for Ampyra) is also being tested as a late-stage compound designed to improve walking ability in patients that have had a stroke at least six months prior and could be a key component to Acorda's long-term growth.

Having earned $0.39 in EPS in 2013, Acorda is projected to net $1.03 in EPS by 2017 for total growth of 164%.

3. Akorn (AKRX)
Last, but certainly not least is Akorn, a unique hybrid pharmaceutical company that develops a handful of innovative branded drugs but also relies on generic drugs to drive its sales and profit growth.

On one hand, it's great having a branded drug portfolio, as branded drugs have high margins and are often protected from generic competition for years, or perhaps beyond a decade once they make it to pharmacy shelves. The downside is that patent life on branded drugs is typically 20 years, and it begins when clinical trials on humans are undertaken.

Source: U.S. Food and Drug Administration.

That's where generic drugs come into play. Generics typically only price at 10%-20% of the cost of an innovator drug, but what they lack in margins or price they make up for in volume. Consumers and insurers will usually aim for cheaper alternative of chemically equal compounds if they're available, meaning generics are likely to play an increasing role in our healthcare system going forward.

According to Akorn's management team, heading into 2013, it had more than three dozen generic compounds it was planning to introduce, so this appears to be playing the largest role in its rapid growth.

Having earned just $0.55 in EPS in 2013, Wall Street estimates peg the company to bring in $2.20 in 2017, or a 300% improvement!

Even if you still prefer MannKind, it couldn't do you any harm to add these fast-growing companies to your watchlist.