EMEA statement on abacavir and the risk of heart attack
Finalising a review of recent data on the risk of heart attack (myocardial infarction) associated with the use of abacavir in HIV-infected patients, the CHMP has concluded that there is insufficient evidence to recommend changes to the therapeutic management of patients. This follows the Committees review of findings from the D:A:D study in April 2008, which concluded that further data were needed to determine this risk.
Data from observational studies that have become available since April 2008, including the French Hospital Database on HIV, have continued to show a possible link between myocardial infarction and the use of abacavir. Data from clinical trials showed low numbers of myocardial infarction and could not exclude a small increase in risk.
However, the CHMP has concluded that there were inconsistencies between the different studies findings, and that a causal relationship between treatment with abacavir and the risk of myocardial infarction can neither be confirmed nor refuted. To date, there is no established biological mechanism that could explain a potential increase in risk.
Nevertheless, when prescribing abacavir-containing medicines, prescribers should take action to minimise modifiable risk factors, such as smoking, high blood pressure and high blood-fat levels. The product information for abacavir-containing medicines will be updated to reflect this information.
Abacavir is a nucleoside reverse transcriptase inhibitor (NRTI) indicated in antiretroviral combination therapy for the treatment of HIV infection. In the European Union, it is available as Ziagen, in combination with lamivudine as Kivexa, and in combination with lamivudine and zidovudine as Trizivir.
The timing of this statement together with its tone and unclear content are not helpful. It appears to add little to earlier statements and doesnt reference any new data, if there are any.
It is perplexing that the regulatory authority that mandated companies to study cardiovascular risk, and approved the design and methods for D:A:D, fails to give weight to the findings from the largest prospective study looking at cardiovascular risks associated with HIV treatment.
As the EMEA is advising patients taking abacavir to be cautioned to minimise cardiovascular risk factors it would be more helpful for the guidance to be clear that this is because there is a reasonable concern raised in the D:A:D and other studies.
EMEA press release Meeting highlights from the Committee for Medicinal Products for Human Use, 20-23 April 2009. (23 April 2009)