Biotech stocks are a sucker for a good catalyst. And they don't care what the overall market is doing when it arrives. Share prices can move north or south in a hurry, with little concern for larger market trends. So it's no wonder that investors tend to pay close attention to clinical and regulatory events for biotechs. With that in mind, here's a look at three biotech stocks with upcoming catalysts that could be major events in the lives of these companies: BioDelivery Sciences International (NASDAQ:BDSI), Pozen Inc. (NASDAQ: POZN), and Keryx Biopharmaceuticals (NASDAQ:KERX)

BioDelivery Sciences awaits word on its opioid dependence drug
Small-cap biotech BioDelivery Sciences is hoping to have the U.S. Food and Drug Administration approve its New Drug Application, or NDA, for Bunavail by June 7 as a treatment for opioid abuse. The company believes Bunavail could see peak sales of up to $250 million a year as an alternative to Suboxone, a sublingual film consisting of ingredients similar to Bunavil. According to BioDelivery, Suboxone generated over $1 billion in sales in the past year as a treatment for opioid dependence.

What's key to understand is that Bunavil's primary difference is that it's placed inside the cheek instead of under the tongue like Suboxone. And given that Bunavil appears to be a bioequivalent of Suboxone per the clinical data, I don't see this regulatory review as a major hurdle to approval. In light of BioDelivery's tiny market cap of $355 million compared with Bunavil's commercial potential, you may want to get this stock on your watch list.

Keryx hoping for good news for its chronic kidney disease drug
Keryx Biopharmaceuticals also has a June 7 target action date for its drug Zerenex, indicated as a potential treatment for hyperphosphatemia in patients with chronic kidney disease, or CDK. Recently, the European Medicines Agency deemed Zerenex's application in Europe "complete," so it could possibly be approved in both the U.S. and Europe relatively soon. The drug was approved in Japan last January.  

Leading up to this review, Keryx shares have jumped over 75% in the past year, giving the company a market cap of $1.22 billion. That's notable, because the current hyperphosphatemia market is believed to hover around $1 billion a year, and is dominated by Sanofi's (NASDAQ:SNY) sevelamer. Moreover, Impax Laboratories (NASDAQ:IPXL) won the right to market a generic version of sevelamer last year, and the launch of the generic was announced last week. In short, Zerenex will be entering a highly competitive market space, if approved.    

What does this mean for Keryx? My view is that Zerenex will be approved come June, but it's hard to imagine that the drug will become a blockbuster for this initial indication. That said, Zerenex will probably perform well enough to justify the company's present market cap, but Keryx will probably need to secure additional approvals for other indications to push the drug into blockbuster status. Overall, I think most of Zerenex's approval as a treatment for CDK has been baked into the company's present share price.  

Pozen is seeking approval for its aspirin therapies for cardiovascular disease
Pozen is expecting to hear word from the FDA about its aspirin therapies PA8140/PA32540 by April 25. The therapies are designed to reduce gastric ulcers for patients taking aspirin as part of a daily regimen to reduce the risk of cardiovascular disease. Previously, Pozen's therapies were set for FDA review in January, but the date was pushed back to April after the FDA requested a bio-availability study between PA32540 and PA8140. The company announced earlier this month that the study has been finished and submitted to the FDA, completing its NDA. So, without any further delays, we should know the drugs' collective fate this week. 

What's important to know is that Pozen has partnered with Sanofi for these therapies, entitling them to milestone and royalty payments moving forward. Sanofi will be responsible for launching the drugs in the U.S., which could happen as early as the third quarter of this year.

Overall, I'm not concerned as much about the approval of these drugs as I am about what they mean to Pozen's bottom line. The deal it inked with Sanofi won't trigger any milestone payments large enough to be viewed as game-changers -- partly because of the commercial issues with Pozen's other proton pump inhibitor Vimovo. So, you may want to look elsewhere for more profitable catalysts in the biotech arena. 

Foolish wrap-up
Regulatory approvals can send biotech stocks soaring in short order, but you need to keep in mind the value proposition of the drug under review. In the cases of Keryx and Pozen, I don't think much additional value will be created by gaining FDA approval for their products. On the flip side, if the FDA decides to surprise investors with a rejection, these stocks will probably fall hard. By contrast, the market doesn't appear to have noticed the compelling potential value proposition of BioDelivery's Bunavil, making it a stock to watch.  

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.