D:A:D finding that abacavir and ddI increase heart attack risk 'incomplete' say FDA

The recent findings from a major study seemingly showing that abacavir (Ziagen) and ddI (didanosine, Videx) increase the risk of heart attack are “incomplete”, US drug regulatory authorities have stated. Nevertheless, the Food and Drug Administration (FDA) will “continue to evaluate the overall risks and benefits” of the two drugs.

In February, surprise results from the D:A:D study were presented to a major international conference that showed that treatment with abacavir was associated with a near doubling in the risk of heart attack, with ddI therapy increasing the risk by nearly 50%.

Makers of abacavir, GlaxoSmithKline (GSK) conducted an analysis of their own clinical trials database to see if the studies leading to the approval of abacavir showed an increased risk of heart attack. According to the FDA statement, “the results of the GSK analysis are inconclusive, but did not show an increased risk.”

A similar analysis was conducted by Bristol Myers Squibb, the makers of ddI. “The results of the BMS analysis are also inconclusive”, note the FDA.

The FDA has stated that it regards the D:A:D study findings as incomplete as they did not include an analysis of abacavir’s chief competitor, tenofovir (Viread), nor another important antiretroviral drug, FTC (emtricitabine, Emtriva).

But the FDA has stated that it will continue to evaluate the risks and benefits of treatment with abacavir and ddI, and that “this may result in the need to revise labeling for the products.” The statement adds, “until this evaluation is complete, healthcare providers should evaluate the potential risks and benefits of each HIV antiretroviral drug their patients are taking, including abacavir and didanosine.”