Oct. 21--Children who once faced lifelong disabilities from arthritis seem to be getting relief from powerful but costly new medicines, according to studies presented in Philadelphia this week.

The new drugs, known as TNF inhibitors, "have totally revolutionized our field," said David D. Sherry, director of clinical rheumatology at Children's Hospital of Philadelphia. "We used to have a lot more kids who were crippled.. . . That has virtually disappeared."

About 80,000 children in this country have chronic juvenile arthritis, and 220,000 have some other rheumatic disease, said Lisa Imundo, director of the division of pediatric rheumatology at Columbia University Medical Center in New York.

"When these agents first came out [in the last decade], we were floored by how quickly they worked and how effective they were" in both children and adults, Imundo said yesterday from the annual American College of Rheumatology meeting at the Convention Center.

"But there have always been safety concerns about the long-term side effects."

The risk of cancer is one.

This summer the Food and Drug Administration required its strongest "black box" warnings on the entire class, which includes drugs sold under the names Humira, Cimzia, Enbrel, and Remicade.

They work by neutralizing the tumor necrosis factor alpha (TNF) protein that helps the body fight cancer cells.

Imundo said there were insufficient data to definitively link TNFs with cancer risk.

Still, the risk of side effects should be weighed against the benefits for patients who often develop long-term disabilities from their arthritis.

"When the house is on fire, you don't worry about water damage," Sherry said. "At the same time, once the fire is out, you do have to deal with the water damage."

So researchers are trying to determine how long patients, particularly children, need to be on heavy doses of these drugs.

Another issue is the cost of these biologics, which can reach $1,000 to $2,000 or more a month, depending on the dosage a patient needs.

Rheumatoid arthritis is an autoimmune disease in which the body attacks its own cells. TNF proteins play a role in causing the immune system to attack healthy tissue. The inhibitors block the protein and reduce the immune response, making patients more vulnerable to infections.

Some patients do well with older -- and less expensive -- drugs such as the decades-old cancer drug methotrexate.

That was true for Christopher Nemitz of Pennington, Mercer County. Nemitz was found to have juvenile arthritis at age 3.

It started in his knee and an ankle. He also developed psoriasis. His mother, Janine Nemitz, said the disease limited her son's activities.

"He couldn't participate in gym and do things with the other kids," she said.

For more than a decade, he has been on generic methotrexate, which costs about $40 a month.

"As soon as he started taking that, the swelling went down," Nemitz said. "He was on the football team, he could do anything."

Now 18, he plays drums and is in his high school marching band, she said.

But other children do less well, and the new drugs help them, said Nemitz's doctor, Donald Goldsmith, chief of the section of rheumatology at St. Christopher's Hospital for Children in Philadelphia.

"We used to have a number of children who . . . would not respond to the early medication and end up with long-term consequences," Goldsmith said. "The biologics have really modified that significantly, really changed the field dramatically."

Even with the older drugs, patients need to be monitored for side effects. Goldsmith was a senior author of a study presented at the conference that said such testing could safely be limited to once every three months for methotrexate.

That could save money from the current once-a-month testing regimen and spare children and parents the pain of monthly blood draws.

Goldsmith, while positive about the newer biologics, cautioned against putting too much weight into a small study released at the conference this week by Finnish researchers. It suggested positive effects from a combination of methotrexate and the TNF infliximab -- sold as Remicade by Horsham-based Centocor Ortho Biotech Inc.

"A good many of these new biologic agents have been studied in children," Goldsmith said, but Remicade is not approved for use in children in the United States.

But the study was promising in that it found all 19 of the children on the combination of methotrexate with the biologic had at least a 75 percent improvement in their condition and 13 were in remission.

The study examined 60 children for just over a year. And it raises hopes that those patients who do not benefit from a single medicine could do well with a combination, including one of the TNF inhibitors.

"We are still not curing any of these kids; they are in remission on medication," said Imundo of Columbia University. "Right now, these patients are going to be on these medications for years and potentially the rest of their lives."

Contact staff writer Josh Goldstein at 215-854-4733 or jgoldstein@phillynews.com.

-----

To see more of The Philadelphia Inquirer, or to subscribe to the newspaper, go to http://www.philly.com/inquirer.

Copyright (c) 2009, The Philadelphia Inquirer

Distributed by McClatchy-Tribune Information Services.

For reprints, email tmsreprints@permissionsgroup.com, call 800-374-7985 or 847-635-6550, send a fax to 847-635-6968, or write to The Permissions Group Inc., 1247 Milwaukee Ave., Suite 303, Glenview, IL 60025, USA.