GSK publishes Avandia cardiovascular safety profile

GlaxoSmithKline (GSK) has sent a letter to the editor of the Lancet on 30 May summarising additional Avandia (roseglitazone) cardiovascular safety data from several large-scale clinical trials.

The letter, which was written by GSKís Chief Medical Officer Dr Ronald L Krall, clarifies the safety record of Avandia from one of the largest research programmes in diabetes.

Key data points include:

• The recent meta-analysis published in New England Journal of Medicine, which has been widely cited in media reports, omitted the total percentage number of events. The actual number of heart attacks represents a very low frequency of events: 0.6 per cent for both Avandia and the control group.

• Further analyses from ADOPT and DREAM, the two long-term prospective clinical trials, show that the incidence of ischemic cardiovascular events with Avandia is comparable to the two gold standard medicines used to treat type 2 diabetes (metformin or a sulfonylurea) in the ADOPT study, and to placebo in the DREAM study.

• Findings from a soon-to-be-published study, using a managed care database of more than 30,000 diabetes patients in a real-world setting, show the incidence of hospitalisations for heart attack, and/ or for a surgery known as revascularisation for patients on Avandia is the same as for other diabetes treatments.

• The independent safety monitoring board for the RECORD trial, which is a large, long-term clinical trial designed to look at cardiovascular outcomes in people with diabetes, reviewed an interim analysis of cardiovascular endpoints in all study participants, and determined that the study should be allowed to continue.

In conclusion, GSK says that the data from long-term, large-scale, prospective clinical trials show that the overall ischemic cardiovascular safety profile, including cardiovascular death, among diabetes patients treated with Avandia is comparable to patients treated with two other widely used diabetes medicines.

The data contrast strongly with the news of the Cleveland Clinicís study released this week, which found the users of Avandia were 43 per cent more likely to have a heart attack than those given other drugs.

Since the Cleveland study was published in New England Journal of Medicine (NEJM), GSKís shares have fallen about 13 per cent, which is equivalent to almost GBP 1bn pounds (USD 2bn) in market value.