Pfizer has been boosted by data which suggests that the firm’s controversial COX-2 inhibitor Celebrex, when used after stent implantation in patients with coronary artery disease is safe and can reduce the need for revascularisation of the target lesion.

Hyo-Soo Kim of the Seoul National University Hospital in South Korea and colleagues have published the results of the Corea-Taxus trial, to be found in The Lancet which looked at whether Celebrex (celecoxib) could prevent the formation of smooth muscle tissue, or neointima, within stents, which can lead to narrowing and eventually re-blockage of the lumen of the stent,, ie restenosis.

All of the 274 patients in the study were given aspirin (100mg) daily and Plavix (clopidogrel;75mg daily). Of these, 136 were randomly assigned to receive Celebrex – 400mg before the stent implantation, and then 200mg twice daily for six months after the procedure. The in-stent lumen diameter of all patients was measured using a coronary angiography six months after implantation.

The researchers found that the average reduction of in-stent luminal diameter was 0·49mm in the celecoxib group and 0·75mm in the control group, which means that Celebrex reduced luminal reduction by 35%. There was also a decreased need for target-lesion revascularisation in the group taking the Pfizer painkiller.

The authors of the study claimed these data suggest that “the adjunctive use of celecoxib for six months after stent implantation in patients with coronary artery is safe," and unlike with Merck & Co’s now-withdrawn COX-2 inhibitor Vioxx (rofecoxib), it does not increase the risk of cardiovascular events. They added that "administration of celecoxib for six months does not seem to increase the risk of adverse cardiac events in the intermediate term when used with dual anti-platelet therapy” and concluded by saying that “we will be interested to see the two-to-five year follow-up results of this cohort."

Not everyone is convinced, however, and in the accompanying editorial, Francesco Pelliccia and Vincenzo Pasceri of the Ospedale San Filippo Neri in Rome, Italy, argue that “although celecoxib might be beneficial even when given for a short time before and after coronary angioplasty, the safety of this drug in interventional cardiology should be confirmed by studies''. They added that gastrointestinal tolerability of the drug in combination with aspirin and clopidogrel could also limit use.

Nevertheless, the study supports use of Celebrex, which Pfizer will be pleased to hear given the concerns regularly voiced about COX-2 inhibitors and their cardiovascular risks. As for another COX-2 inhibitor, Novartis’ Prexige (lumiracoxib) has just been pulled from the market in Australia over fears of liver damage, not the best news ahead of a bid to get approval from the US Food and Drug Administration next month. If that fails, Celebrex will retain its position of being the only COX-2 inhibitor on the market in the USA.