FDA panel rejects Celebrex's marketing requestNov 5, 2001 | USA Today The makers of the wildly popular arthritis drugs Celebrex and Vioxx may wish they had left well enough alone. Pharmacia failed to convince a Food and Drug Administration advisory committee Wednesday that it should be allowed to market Celebrex as safer on the stomach than other non-steroidal anti-inflammatory drugs, or NSAIDs. The FDA usually follows the recommendations of its advisory committees. In addition, the drug company's data ended up raising concerns about possible adverse cardiovascular effects.
If a review by FDA doctors posted Wednesday on the agency's Web site is any indication, Merck, maker of Celebrex rival Vioxx, will face similar issues during its appearance before the advisory panel today.
Celebrex and Vioxx are known as COX-2 inhibitors. Actually, all NSAIDs, which include aspirin and ibuprofen, inhibit COX-2, an enzyme involved in pain and inflammation. Celebrex's and Vioxx's selling point — to the tune of more than $3 billion last year — has been that they are the only NSAIDs that do not also inhibit COX-1, an enzyme thought to keep stomach lining intact.
Clinical trials that led to the approval of Celebrex and Vioxx suggested that the drugs were safer on the stomach. But the manufacturers had to conduct bigger and longer-term studies to drop a warning about serious ulcers that all NSAIDs carry.
The six-month clinical trial, CLASS, failed to show a lower rate of serious ulcers in Celebrex patients compared with those on ibuprofen or diclofenac, FDA reviewers concluded. Taking low-dose aspirin to protect against heart attacks appeared to increase the rate of serious ulcers in Celebrex patients, leading the advisory panel to recommend studies into the relationship between COX-2 inhibitors and aspirin.
FDA medical officer James Whitter concluded that the CLASS findings did not show Celebrex to have a much greater risk of cardiovascular mortality or blood clots. But the data did not rule out less obvious adverse effects from decreased blood flow to the heart, Whitter said.
In her review of Vioxx, FDA medical officer Maria Lourdes Villalba writes that that drug also should continue to carry the same warning as other NSAIDs about gastrointestinal (GI) problems such as ulcers, bleeding and perforation. In addition, Villalba writes that information about a risk of heart attacks and strokes should be added to the label.
Sidney Wolfe with the Public Citizen Health Research Group, who spoke at the meeting, urged the FDA to require a patient-friendly "medication guide" for all NSAIDs outlining risks of stomach and cardiovascular complications.