Just 1 week after receiving a nonapprovable letter for their new osteoporosis drug lasofoxifene (Oporia), Pfizer Inc announced Tuesday that the Food and Drug Administration (FDA) has issued a nonapprovable letter for parecoxib sodium (Dynastat®)¹, an injectable cyclooxygenase (COX)-2 inhibitor used to treat acute pain in the postsurgical setting.

While neither the FDA nor Pfizer can comment on the specifics or merits of the nonapprovable letter, a Pfizer spokesperson tells CIAOMed, the company disagrees with the conclusions stated in the nonapprovable letter and plans to meet with the regulators to discuss the agency's concerns.

As the only injectable COX-2–specific inhibitor, parecoxib would provide physicians with a new and much-needed option in the treatment of acute pain. When administered for short periods of time, parecoxib has been shown to reduce the need for opioids to control pain following surgery.

Casualty of coxib controversy?

Parecoxib is a prodrug of valdecoxib, which the FDA requested be withdrawn from the market earlier this year, citing "no added advantage" and a special risk of Stevens-Johnson syndrome. However, the European Medicines Evaluation Agency concluded earlier this year that, based on the overall safety data and with appropriate labeling, "the benefits [of Dynastat] continue to outweigh the risks." Many other regulatory agencies worldwide conducted similar reviews and arrived at the same conclusion. Currently, parecoxib is available worldwide, chiefly under the brand name Dynastat.

An anesthesiologist's opinion

"Parecoxib would fill an unmet need in the anesthesiologist community," says Jeffrey Katz, MD, associate professor of anesthesiology at the Northwestern University Feinberg School of Medicine in Chicago, Illinois. "In my opinion, the FDA is disregarding the fact that anesthesiologists know how to administer the drug in the operating room," he tells CIAOMed. "It's a straightforward drug, and we know when to use it and we know how to use it."

Dr. Katz explains that while "narcotics are the mainstay of perioperative pain management; it's well known that they have problems and are not enough to treat postoperative pain." Pointing out that ketorolac was introduced and widely used for a time, he notes that "this agent caused renal failure and perioperative bleeding in some patients, so we can barely use it anymore. The bleeding issue is out of the picture with parecoxib; therefore, it would wipe out the need for ketorolac."

Reference

1. Pfizer receives FDA nonapprovable letter on parecoxib [press release]. PR Newswire; September 20, 2005.