FDA OKs New Painkiller Drug for Arthritis
The Food and Drug Administration on Thursday approved a long-anticipated arthritis medication that is the first in a new category of anti-inflammatory drugs. But it downplayed earlier suggestions that the drug would avoid some of the serious side effects of existing products.
The drug, Celebrex, made by G. D. Searle & Co. of Chicago, was approved for use by the nearly 3 million Americans who suffer from rheumatoid arthritis and the estimated 37 million afflicted with osteoarthritis.
The first in a new class of drugs known as “COX-2 inhibitors,” it will be available only by prescription.
Expectations had been high that the drug would not produce the potentially life-threatening stomach bleeding and ulcers sometimes caused by regular use of other non-steroidal anti-inflammatory medications. The FDA said the drug “might deliver” on this promise, but cautioned that studies conducted so far have not provided definitive proof.
“It is safe and effective,” said Dr. Murray M. Lumpkin, deputy director of the FDA’s center for drug evaluation and research. “But it’s not necessarily safer than the products that are already out there.”
The drug will be available early this year, and will cost up to $3 a day, depending on dosage. The cost is comparable to other prescription painkillers, the company said.
Most arthritis patients take non-steroidal anti-inflammatory drugs, or NSAIDs, such as aspirin, acetaminophen and ibuprofen. These reduce pain by blocking production of chemicals known as prostaglandins. But they can cause stomach irritation and bleeding ulcers, among other side effects.
These drugs work by blocking the action of an enzyme, cyclooxygenase-2 (COX-2), which inhibits the production of prostaglandins. But they also halt the production of cyclooxygenase-1 (COX-1), which is an enzyme that protects the lining of the stomach.
Researchers have been trying to find alternative drugs that could inhibit COX-2, while not interfering with the production of COX-1. Celebrex does both.
But the FDA was not sufficiently satisfied with existing studies to allow Celebrex to make the claim that it protects against stomach bleeding and ulcers.
“There is a lot about this drug that might deliver this promise, but the data haven’t proved it yet,” Lumpkin said.
In clinical trials, patients taking Celebrex did, in fact, have a substantially lower risk of ulcers as detected by endoscopy--a procedure that examines the gastrointestinal tract using a device known as an endoscope--over 12 to 24 weeks, compared to patients taking other NSAIDs.
Patients with endoscopic ulcers often recover without special treatment and without experiencing symptoms. Often such ulcers are found only when patients undergo endoscopy for other reasons, Lumpkin said, so many such ulcers could have gone undetected.
Additional studies and experience with many thousands of patients will be needed to determine whether Celebrex actually causes fewer gastrointestinal problems than other NSAIDs, the agency said.
The FDA said additional studies and post-marketing experience will “add substantially” to how this drug compares to other NSAIDs now on the market.
Company officials said they were not disappointed by the agency’s caveat, and they predicted that greater use will establish its gastrointestinal protective qualities.
“I think the medical community is very familiar with this drug, and recognizes its significance,” said Dick De Schutter, Searle’s chief executive.
“We expect as the drug finds widespread use in millions of patients--and as we continue to set up new clinical trials--that [elimination of side effects] will be established beyond a doubt,” he added.
The labeling, however, does warn consumers to be alert for possible signs of ulcers or gastrointestinal bleeding, which include skin rash, unexplained weight gain or swelling.
The drug is not approved for general pain relief--for such maladies as headache or muscle soreness--but only for the two types of arthritis.
Osteoarthritis is caused by the general effects of aging. In the more serious rheumatoid arthritis, the patient’s immune system goes awry, attacking the joints and causing inflammation and stiffness. Cartilage is destroyed and joints often freeze, making routine tasks impossible.
About 13 million Americans take NSAIDs regularly. An estimated 76,000 of them are hospitalized annually for the ulcers produced, and 7,600 die from them.
Celebrex has some side effects, including dyspepsia, diarrhea and abdominal pain. Yet fewer than 1% of patients in the trials stopped using the drug as a result of these side effects, the company said.
