US panel backs Pfizer drug for juvenile arthritis
Last Updated: 2006-11-30 10:06:04 -0400 (Reuters Health)
By Lisa Richwine
GAITHERSBURG, Md (Reuters) - Pfizer Inc.'s pain reliever Celebrex should be approved for treating rheumatoid arthritis in children despite uncertainty about the risks of long-term use, U.S. advisers said on Wednesday.
The blockbuster prescription drug is the only medicine still on the U.S. market from the class called COX-2 inhibitors, which were linked to an elevated risk of heart attacks and strokes in adults.
Members of a U.S. Food and Drug Administration committee unanimously said Celebrex appeared effective as a therapy for juvenile rheumatoid arthritis. But they urged the FDA to ask Pfizer to closely track potential side effects in children who take the drug for several months or years.
"We really don't know anything about the safety of this drug in the long-term for children," said Dr. Patricia Chesney, a panel member and director of academic programs at St. Jude's Children's Research Center.
Still, members said it was important to have a variety of approved options for children with rheumatoid arthritis, as not all of them respond to each drug.
The panel voted 15-1 to urge FDA approval of Celebrex for the juvenile disease, saying benefits outweighed risks. Earlier the panel had voted 8-7 with one abstention that current data do not demonstrate Celebrex is safe for the condition.
Pfizer already markets Celebrex to treat various forms of arthritis and other conditions.
The drug's third-quarter sales jumped 20 percent from a year earlier to $537 million, the company reported last month.
While doctors can prescribe Celebrex to children now, FDA approval would allow Pfizer to market the drug specifically for juvenile rheumatoid arthritis. The company said on Tuesday it did not plan consumer advertisements for that purpose.
The COX-2 inhibitors faced heightened scrutiny after Merck & Co Inc. pulled Vioxx in 2004, citing a study that found prolonged use doubled heart attack and stroke risk. Pfizer withdrew another COX-2 inhibitor, Bextra, in 2005.
Celebrex, or celecoxib, stayed on the market with a new warning that it may raise the chances of serious and possibly fatal heart problems, as may other non-steroidal anti-inflammatory drugs (NSAIDs) used to fight pain.
Pfizer won an extra six months of exclusive marketing time for Celebrex in exchange for the study of juvenile rheumatoid arthritis, a disease that afflicts about 30,000 to 60,000 U.S. children when their immune system attacks the joints.
The severity of the condition varies, but some cases can cause disabling joint swelling and pain, decreased range of motion and abnormal growth.
In the Pfizer study, children ages 2 to 16 took either Celebrex or the NSAID naproxen for 12 weeks. The percentages of children who benefited were similar in both groups, as were side effects, the company said.
Pfizer said naproxen and other NSAIDs used to treat children with rheumatoid arthritis also carry heart risks for adults, and little is known about their long-term effects in children.
"Available data show celecoxib has a similar safety profile to other NSAIDs," Dr. Simon Lowry, senior director of medical affairs for Pfizer, told the panel.
The drugmaker has proposed a new Celebrex formulation for pediatric use -- a capsule that can be opened and the contents sprinkled onto applesauce. Some panelists said that would offer a helpful alternative for youngsters who cannot swallow pills.
Before the final panel vote, shares of New York-based Pfizer closed up 2 cents to $27.07 on the New York Stock Exchange.
