Celebrex risks cardiovascular problems - Otago

Celebrex has similar risk of cardiovascular problems to Vioxx

Intensive Medicines Monitoring Programme Publishes Important Safety Data on New Zealand Patients Taking COX-2 Inhibitors

Patients taking the arthritis drug celecoxib (Celebrex) have a similar risk of heart attacks and stroke as those taking the withdrawn drug rofecoxib (Vioxx), according to a new study by the New Zealand Intensive Medicines Monitoring Programme (IMMP).

Published later this week in the international journal Drug Safety, the University of Otago study is an interim analysis following up approximately 11,000 of the 60,000 patients prescribed either medicine during 2001. Patients’ doctors were asked to supply information about adverse clinical events that occurred since being prescribed the drugs.

The study shows that in the patients who had been followed up, there was no significant difference in the risk of thrombotic cardiovascular events (heart attacks and strokes) in patients taking celecoxib compared with those taking rofecoxib, says IMMP Head and study principal investigator Dr Mira Harrison-Woolrych.

“It was important to perform this interim analysis at this time, as the withdrawal of rofecoxib sparked world-wide concerns about the safety of celecoxib. This is the first study to directly compare the cardiovascular risks of celecoxib with rofecoxib in a ‘real-life’ post-marketing setting,” says Dr Harrison-Woolrych.

“However, while this group of 11,000 patients is clearly defined and reasonably large, it should be understood that it may not be large enough to detect small differences in the rate of relatively uncommon events, such as heart attacks and strokes,” she says.

The Editor of Drug Safety, Ms Rosie Stather, commented that the results from the IMMP study were an important contribution to the growing international evidence on the safety of COX II inhibitors.

“Together with information from other studies, the IMMP results will assist healthcare decision-makers in assessing the advantages and disadvantages of celecoxib in order to make recommendations regarding its use,” Ms Stather says.

CONTACTS:

Dr Mira Harrison-Woolrych Director IMMP University of Otago Ph: 03 479 5164

Ms Rosie Stather Editor Drug Safety Journal Ph: 09 477 0700 ext 7071

Simon Ancell Media Specialist University of Otago Ph: 03 479 5016 027 279 7223

FACT SHEET:

Issue A study by the New Zealand Intensive Medicines Monitoring Programme (IMMP), published this week in the international journal Drug Safety*, has shown that patients taking the arthritis drug celecoxib (Celebrex) have a similar risk of heart attacks and stroke as those taking rofecoxib (Vioxx), which was withdrawn from the market for this reason.

Background In October 2004, the manufacturer of the COX-2 inhibitor medicine rofecoxib (Vioxx) withdrew the product from the worldwide pharmaceutical market because of concerns about serious cardiovascular risks. This raised concerns as to whether celecoxib (Celebrex), the most popular alternative to rofecoxib, carries the same risks as rofecoxib.

The IMMP is a national unit, based at the University of Otago and funded by the Ministry of Health, which monitors the safety of specific medicines after they are licensed for use in New Zealand. The IMMP has been monitoring the safety of COX-2 inhibitors since 2001. The IMMP is one of only two monitoring programmes in the world that proactively studies the safety of newly marketed drugs.

How the study was performed During 2001 the IMMP collected data from about 60,000 patients throughout New Zealand who were prescribed either rofecoxib or celecoxib during this one year period. Information collected on these patients included parameters such as age and sex, the dose prescribed and the reason for use of rofecoxib/celecoxib. Having established these cohorts of patients, the IMMP then sent out questionnaires to patients’ doctors requesting information on all adverse clinical events since starting the medicine. By the time rofecoxib was withdrawn last year, about 11,000 of the patients in the IMMP cohorts had been followed up. It is the results from these patients which are presented in the paper published this week in Drug Safety.

Results of the study This study showed that in approximately 11,000 New Zealand patients who had been followed up using the routine IMMP methodology, there was no significant difference in the risk of thrombotic cardiovascular events (heart attacks and strokes) in patients taking celecoxib compared with those taking rofecoxib.

Dr Harrison-Woolrych commented that the IMMP has been able to do this comparative study as both rofecoxib and celecoxib were monitored at the same time in New Zealand.

“It was however important to adjust the results for differences between the two groups - for example, the celecoxib cohort was older and more likely to be taking the medicine long term,” she said.

Dr Harrison-Woolrych stressed that the results are based on an analysis of only 11,000 of the 60,000 patients in the IMMP cohorts. “Whilst this is a reasonably large number of patients, it may still not be large enough to detect small differences in the rate of heart attacks and strokes which are relatively uncommon events.”

Contribution to international safety data on COX-2 inhibitors The unexpected withdrawal of rofecoxib in late 2004 raised important issues for patients, clinicians, pharmaceutical companies and regulatory authorities. One question is whether the increased risk of cardiovascular events seen with rofecoxib is confined to that agent or whether it is a class effect. “The lack of long-term, prospective data has made analyzing this problem very difficult,”said Rosie Stather, Editor of Drug Safety. “That is why this IMMP study is so important – it is a post-marketing study in a “real-life” setting, where there are none of the exclusion criteria that apply in the highly-controlled environment of a clinical trial.”

* Harrison-Woolrych M, Herbison P, McLean R, et al. Incidence of Thrombotic Cardiovascular Events in Patients Taking Celecoxib Compared with Those Taking Rofecoxib: Interim Results from the New Zealand Intensive Medicines Monitoring Programme. Drug Safety 2005; 28 (5): 435-442 (see http://www.adisonline.info/current.asp?J=drs for a link to the online version from 15.4.05)

Further information on the IMMP study Further information on the IMMP COX II inhibitor study and the work of the IMMP can be obtained from Dr Mira Harrison-Woolrych on direct dial 03 479 5164 or at Mira.harrison-woolrych@stonebow.otago.ac.nz Please note Dr Harrison-Woolrych will not be available between 15.4.05 and 26.4.05 inclusive.

Further information on COX II inhibitors Further information on COX II inhibitors and New Zealand regulatory action to date can be found at the Medsafe website (www.medsafe.govt.nz)

Further information on Drug Safety Drug Safety is an international, peer-reviewed journal with a strong reputation for evaluative reviews, cutting-edge research and its independent stance on drug safety issues. The official journal of the International Society of Pharmacovigilance, published by Adis International Ltd, Wolters Kluwer Health, Drug Safety is in its 19th year of worldwide publication.

Wolters Kluwer Health is a unit of WoltersKluwer nv, a leading multinational publisher and information services company with annual revenues (2004) of € 3.3 billion and employing approximately 18,400 people worldwide. Wolters Kluwer is headquartered in Amsterdam, the Netherlands. Its depositary receipts of shares are quoted on the Euronext Amsterdam (WKL) and are included in the AEX and Euronext 100 indices. For more information, visit www.adis.com and www.wkhealth.com

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