Shareholders of NPS Pharmaceuticals (NASDAQ: NPSP) should be patting themselves on the back. With the Food and Drug Administration approving Gattex -- the company's first regulator-approved drug -- for patients with short bowel syndrome, NPS has cleared the most important hurdle blocking its future. Approval is only the first step for the company to succeed with Gattex, however -- but there are three strong reasons you should take a look at investing in this rising new biotech star.

Growing up with Gattex
For the company's first drug, Gattex is no slouch. The FDA awarded orphan drug designation to the product, granting it extra years of patent exclusivity that will greatly help NPS' long-term goals in establishing a successful future.

Gattex's price tag, on the other hand, is considerable -- and could be considerably rewarding for your portfolio. The company has priced the drug at $295,000 annually; it's a stiff order, to be sure, but not one that should raise your eyebrows too much. Successful orphan drugs in the past have done so regardless of price tag, with Alexion Pharamceuticals' (ALXN) Soliris -- at $400,000 per year, at the time the most expensive drug in the world -- seeing huge growth and hundreds of millions of dollars per year in sales, despite a small market to work with.

NPS should be able to do the same with Gattex, even with only several thousand patients likely to be eligible for treatment, according to the company's CEO. NPS has set peak sales expectations of $350 million -- a modest number that, should NPS reach it (which looks easily possible considering that price tag and the drug's effectiveness for a condition that hasn't seen a treatment advance in decades), will propel the company and the stock to new heights.

Things are even better if NPS can gain FDA approval to use Gattex in treating more common types of gastrointestinal disorders. As Gattex works by repairing the intestinal tract, it's possible that NPS may one day be able to market the drug to patients with Crohn's disease or other ailments. Hundreds of thousands of Americans alone suffer from Crohn's, and while I wouldn't stake my portfolio on NPS' ability to expand Gattex, doing so could make a good thing so much better.

More punch in the pipeline
Gattex isn't all that NPS has going for it in terms of drugs, however -- and one potential pipeline product demands your attention.

NPS is expected to submit a biologics license application to the FDA later this year for its second drug, Natpara, for hypoparathyroidism, a rare disease with few treatments that can lead to respiratory failure and worse in patients. The disease affects less than 200,000 people in the U.S., but like Gattex, don't let the small number fool you. NPS' CEO figures that Natpara could hit peak sales of $250 million annually if the drug clears regulatory hurdles.

While Natpara hasn't passed the FDA yet, it's already selling under a license agreement with Takeda Pharmaceuticals in Europe, as a treatment for osteoporosis. NPS doesn't make much from this deal, but just the fact that the drug has already found success in a market makes its hopes for passing the FDA's regulatory gauntlet all the more optimistic.

If NPS scores another victory with Natpara to go with a successful launch of Gattex, shares should soar. However, there's one final major event that could mean even more green for investors.

Will big pharma come calling?
Merger and acquisition activity has been down among big pharma companies recently, declining 35% last year. However, just because the numbers are down doesn't mean that NPS isn't an attractive target for a company looking for a lucrative takeover. While NPS might not have the emerging market sweet spot that seems to dominate pharmaceutical headlines these days, Gattex's potential in the gastrointestinal market can't be ignored.

The GI market hasn't had a lot of attention on it in the past, with few approved drugs on the market. With an aging population requiring more health care, however, NPS could be on the front lines of major companies looking to carve out a spot.

Pfizer (PFE -0.19%) is an easy candidate to speak of, considering that the company's still on the lookout for replacements for record-setting blockbuster Singulair following its loss of patent protection. The company has made no bones about its desire to go on the M&A prowl to make up lagging sales; as NPS shouldn't have too high of a price tag, Pfizer could likely pull the trigger on a deal without risking too much. However, Pfizer's GI product portfolio is fairly small, and while the company would likely love to add to that, it doesn't speak to many -- if any -- synergies useful for a takeover.

There are plenty of pharmaceutical companies ripe for a mid-size to smaller acquisition like this, however. Eli Lilly (LLY -1.81%) comes to mind, particularly as the company's CEO has expressed little need for a large, eye-popping takeover. With the company holding plenty of cash and investments, NPS could be the right partner for a buyout.

NPS' stars are aligning
In all, the FDA's approval of Gattex has pushed NPS in the right direction, but this company doesn't look like it'll be slowing down any time soon. With Gattex's potential peak sales in the hundreds of millions of dollars, along with Natpara's potential ceiling, should it be approved, this company could very well carve out a lucrative and extremely successful niche with orphan drugs. Should a big pharma player come calling, investors should still make out quite well. While there always remains the possibility that the FDA could nix Natpara and something horrible could happen to Gattex, right now these three signs all point to a bright future for NPS -- and for its investors.