FDA on Thursday announced that it will review the safety of GlaxoSmithKline's antiretroviral drug abacavir and Bristol-Myers Squibb's antiretroviral didanosine, Reuters reports. The agency said that data pooled from a recent study conducted among more than 33,000 HIV-positive people found that the antiretrovirals were linked to an increased risk of heart attack among some of the participants.
Didanosine is a generic version of BMS's VIDEX, which was FDA-approved in December 2004. The drug is used in combination with other antiretrovirals for the treatment of HIV-1 infection. Abacavir is a second-line antiretroviral used to treat people living with HIV/AIDS who have developed resistance to first-line drugs. Abacavir is sold under the brand name Ziagen. GSK and BMS said their own evaluations have not found an increased risk of heart attack.
According to FDA, people taking either drug "had a greater chance of developing a heart attack than patients taking other medications." However, the risk did not increase over time and seemed to diminish after people stopped taking the drugs, the agency said. "The effect was not seen six months after stopping the drugs," FDA said. In a notice on its Web site, FDA said it is still evaluating the data and that the review "may result in the need to revise labeling for the products." The agency added that the current analysis of the study is incomplete, noting that researchers have not evaluated the risk of heart attack associated with Gilead Sciences' Viread and Emtriva. "Until this evaluation is complete, health care providers should evaluate the potential risks and benefits" of antiretrovirals their patients are taking, the agency said.
Marc Meachem, a GSK spokesperson, said the company has analyzed its own databases and "did not see any sign of an increased risk of heart attack." BMS spokesperson Sonia Choi said that the company has not "seen an increase of cardiovascular events in our studies of VIDEX or in our (company) safety database." FDA said that the results from analyses by GSK and BMS are inconclusive, according to Reuters. Mark Schoenebaum, an analyst for Bear Stearns, said in a research note that he believes safety concerns with GSK's abacavir "will drive increased switching to Gilead-based regimens".