As 2013 winds down, it's time to turn our attention to what's in store for biopharma in the New Year. Looking ahead, the schedule is jam-packed with pivotal clinical trial data results, regulatory and commercialization milestones, among many other events. So it's safe to say that 2014 is going to be another big year for drugmakers.

With that in mind, here's a Foolish look at three drugmakers with key regulatory issues coming up.

Pimavanserin going down regulatory road
Acadia Pharmaceuticals (ACAD -1.78%) is planning to file a New Drug Application, or NDA, for its lead drug candidate pimavanserin next year. As a refresher, pimavanserin is intended as a front-line treatment for Parkinson's disease psychosis, or PDP after the drug met all of its primary endpoints in a late-stage study earlier this year. After meeting with the FDA last April, Acadia now believes the path to approval is clear.

Specifically, Acadia believes that standard supportive studies are the last remaining elements to a successful NDA filing. The company expects to complete this additional work by mid-2014, followed by a NDA filing by the end of 2014. If all goes according to plan, pimavanserin could be approved as early as the middle of 2015.

Why is pimavanserin a big deal? Firstly, Acadia has retained worldwide commercialization rights to the drug, which is rare for a company's first commercial drug candidate. And with the market expecting peak sales of around $300 million per year, pimavanserin could be a major revenue generator. Yet, it's important to keep in mind that Acadia shares are currently priced at six times projected peak sales, and the drug hasn't even been reviewed. So it's not exactly a bargain.

My take is that Mr. Market is looking down the road to a label expansion for other neurological and psychiatric disorders. While Acadia is indeed studying the drug in two mid-stage trials for other indications, speculation about a label expansion is putting the proverbial cart before the horse. A number of regulatory risks still remain for the drug's primary indication, and it's important to keep these in mind. As such, you might want to hold off on jumping into Acadia until the price better reflects these risks. 

Keryx pins its hopes on Zerenex
Keryx Biopharmaceuticals (KERX) is hoping its flagship drug candidate Zerenex will be approved by the FDA in the second half of 2014 as a treatment for elevated serum phosphorus levels in patients with advanced kidney failure on dialysis. The drug's Prescription Drug User Fee Act, or PDUFA, target date is set for June 7.

Keryx announced earlier this year that a late-stage trial performed under a Special Protocol Assessment, or SPA, with the FDA, showed that Zerenex dramatically lowers serum phosphate levels, and is generally well-tolerated. And the company's ongoing extension studies paint a similar picture of the drug's benefits. In a nutshell, Zerenex stands a good chance of approval next year.

Why is this story worth watching? Experts are expecting peak sales for Zerenex to top $500 million, and Keryx has begun mid-stage trials to assess the drug in non-dialysis dependent kidney disease patients. In short, Keryx shares are only selling at two times peak potential sales, which is cheap by industry standards. Viewed in that light, you might want to keep tabs on Keryx going into 2014.

Ariad hopes for a change of heart from the FDA
Ariad Pharmaceuticals (NASDAQ: ARIA) is trying to convince the FDA that its blood cancer drug, Iclusig, should be allowed back on the market after being pulled due to excessive risk of blood clotting. The drug is still on the market in Europe, however, after the European Medicines Agency, or EMA, put forth a set of guidelines for the drug's use. Ariad is hoping for a similar decision from the FDA next year.

My take is that the best Ariad can hope for is that Iclusig is allowed back on the market as a therapy of last resort. The FDA pulled the drug for safety concerns, and it's unlikely to do a complete about face. And now the EMA is also indicating it needs to further assess the drug's safety profile, which is unwelcome news for Ariad investors. So it's looking like the EMA is more likely to have a change of heart than the FDA.