It was a sad day when I heard that the COX-2 inhibitor Vioxx was being pulled off the market. The drug previously manufactured by Merck (NYSE:MRK) was primarily targeted at sufferers of joint pain. Being a distance runner in college, I suffered my share and began taking it for a bad back at age 21. Given its results, I was not surprised by the billions of dollars in revenues that it would go on to generate. 

The plug was pulled on that revenue source, but Merck is still in the race. It has developed a new drug, and although the Vioxx situation places hurdles in its path, if the new tonic gets approval, it could help the company chip into Pfizer's monopoly of the osteoarthritis market and reward Merck shareholders over the long run.

Pfizer (NYSE:PFE) manufactures Celebrex.

I was pretty concerned when I heard Vioxx was being recalled, not because of the alleged side effects, since I hadn't experienced any, but rather the fact that I was relying on it to run pain-free. Luckily I was able to transition onto Celebrex.

For a few years now, Pfizer has been able to enjoy its monopoly of the osteoarthritis market given the lack of a formidable, FDA-approved competitor to its Celebrex. This soon may not be the case. An FDA advisory panel is meeting tomorrow to discuss Arcoxia. 

Arcoxia is in the same class of COX-2 inhibitors and would be the first COX-2 inhibitor to gain approval since Vioxx and Pfizer's Bextra were recalled from the market in 2004 and 2005. In clinical trials it contained the same level of cardiovascular risk as diclofenac, now a generic anti-inflammatory drug also sold as Voltaren by Novartis (NYSE:NVS).   

The prospects of such approval have had a minimal impact thus far on Merck's share price. Many analysts are skeptical that Arcoxia will be approved and even if it is, they doubt that the sales it would generate would have a material impact on Merck's total revenue figures given the skepticism following its Vioxx recall.

Vioxx achieved $2.5 billion in sales in 2003, the year before it was recalled, and Celebrex achieved $2.0 billion in sales this past year. I can understand the skepticism and the perception that the recall of Vioxx left a huge gap to fill for Merck, hence the subsequent introduction of Arcoxia. However I believe if Arcoxia is approved despite the long odds against it, it could payoff over the long run for Merck shareholders. Given the size of the COX-2 market, any positive results achieved by this drug could go a long way toward putting a small dent in Pfizer's command over the market.        

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Fool contributor Billy Fisher does not own shares of any of the companies mentioned. The Fool has a disclosure policy.