Celebrex - the only Vioxx-like drug still on drugstore shelves - could soon be sold specifically as a treatment for rheumatoid arthritis in children if the Food and Drug Administration approves a Pfizer request to do so.
The FDA has already approved Celebrex (celecoxib) to fight pain and inflammation but not specifically for use in children. Only 20 percent to 30 percent of FDA-approved drugs are specifically labeled for pediatric use.
But now Manhattan-based Pfizer is seeking FDA approval to market Celebrex specifically in children 2 years and older who have rheumatoid arthritis.
Doctors already prescribe Celebrex for children with rheumatoid arthritis because once the FDA approves a drug for one purpose, doctors may prescribe it as they see fit in a practice known as "off-label" use.
However, the FDA can reward companies that test the effects of their drugs on children by extending their patents for six months.
Because most drugs are tested only on adults, the idea is to use patent extensions to encourage drug companies to make sure their products are safe for children. The payoff: six extra months of marketing exclusivity for the drug companies.
Dr. John LeCroy, an analyst for Manhattan stockbroker Natexis Bleichroeder, said it's unlikely an FDA approval for using Celebrex in children with arthritis will garner more yearly sales for Pfizer because doctors already prescribe it for that use.
"Typically, the drug companies do this in general to get an extra six months exclusivity on their patent," LeCroy said.
LeCroy said Celebrex sales peaked in 2004 at $3.3 billion, then decreased to $1.7 billion in 2005 and finally flattened out in September. He expects worldwide sales of about $2 billion for 2006.
After the Vioxx scandal - thousands of patient lawsuits alleged the drug caused fatal heart attacks and strokes - Celebrex was the only drug that remained on the market out of a group of medications called COX-2 inhibitors, which were considered a breakthrough in arthritis treatment.
Doctors prescribed the COX-2 inhibitors to treat arthritis pain and inflammation. Vioxx was the best-known COX-2 inhibitor, but Merck and Co. Inc. pulled it off the market after its legal problems began.
And although Pfizer's Celebrex survived the COX-2 inhibitor purge, Bextra, Pfizer's other drug in that class, was, like Vioxx, removed from the market.
Celebrex, deemed safer than Vioxx, has had its own problems. The drug's label now carries a so-called black box that warns it could increase the chance of a fatal heart attack, stroke or gastrointestinal bleeding.
And in the past, the Washington, D.C., watchdog group Public Citizen has called for Pfizer to remove Celebrex from the market.
Dr. Anne Eberhard, chief of pediatric rheumatology at North Shore University Hospital in Manhasset, said rheumatoid arthritis affects one in every 1,000 to 2,000 children. Symptoms include morning stiffness, pain, sometimes a limp and swelling in the joints, Eberhard said.
Eberhard said she has prescribed it for some children and hasn't seen any heart or stroke problems. She said she always advises parents about possible Celebrex side effects.
"We've never seen that in children," Eberhard said, noting that children tend to have healthy cardiac systems. "In general, we do see good results."
Eberhard said some insurance companies won't pay for Celebrex for children, and an FDA approval for that purpose might persuade more insurers to pay for the drug.
Shreya Prudlo, a Pfizer spokeswoman, said although the company has asked that Celebrex be approved for a specific use in children, "We remain open to a range of labeling options because we feel these data [submitted to the FDA] provide important safety information for physicians and patients."
Prudlo said juvenile arthritis is almost as common as childhood diabetes or childhood epilepsy.
"Again, our goal is to share data on the use of Celebrex in patients with limited treatment options," Prudlo said.
The FDA's Arthritis Advisory Committee plans to meet Nov. 29 to consider Pfizer's findings on the use of Celebrex in children before making an approval recommendation to the agency.
source - Newsday