Little benefit for Celebrex and Vioxx in wake of FDA panel review

As reported briefly in the Marketletter last week, a US Food and DrugAdministration advisory panel has declined to recommend approval of a label change for Pharmacia and Pfizer's COX-2 inhibitor Celebrex (celecoxib) which would have allowed the removal of a warning, which appears on all non-steroidal anti-inflammatory drugs, that its use may be associated with gastrointestinal ulcers and bleeding.

There was presumably some comfort for the firm on the news that Merck & Co had failed to secure backing for a similar application for its rival COX-2 inhibitor Vioxx (rofecoxib). However, the panel did recommend that Vioxx should have its labeling changed to reflect that it has been shown cause fewer GI side effects than the NSAID naproxen in patients with rheumatoid arthritis, an indication for which it is not yet approved in the USA. Similarly, Pharmacia and Pfizer have interpreted the panel's deliberations as indicating that Celebrex may be able to state on the label that it has better GI tolerability than ibuprofen.

However, the panel expressed its concerns over data from the 8,000-patient VIGOR trial of Vioxx, in which significantly fewer heart attacks were observed in patients taking naproxen compared to those on Vioxx, although there was no difference in cardiovascular mortality between the groups. It rcommended that the prescribing information for both Vioxx and Celebrex should reflect the fact that neither of these selective NSAIDs confer cardioprotective benefits, so they are not a substitute for low-dose aspirin for prevention of cardiovascular events in patients who cannot tolerate the latter drug.