Reactions

"I take the findings in the [ACTG] study as serious. They represent a concern, and we need to be vigilant," Edwin De Jesus, MD, an HIV physician with a private practice in Orlando, Florida, told Medscape HIV/AIDS. He cautioned that only 1 group of the study has been stopped, whereas the others continue on toward their 96-week conclusion. The full data have not been unblinded, so the possible contribution of other drugs in the regimens is not known.

"The fact that some of the patients were not screened for hypersensitivity reactions, for HLA 5701," may also play a role, he said, noting that he looks forward to seeing further data from the study.

Bob Huff, from the AIDS think tank Treatment Action Group (TAG), thought it was important to remember that the DSMB did not stop the lower viral load strata of the trial. That presumes it did not have a similar concern with excess negative events in that patient population. Perhaps, therefore, events in the high viral load group were a fluke, he said.

Mr. Huff was shocked to hear that a patient in the ACTG trial had died of a hypersensitivity reaction on restarting abacavir treatment. He told Medscape HIV/AIDS, "If it is happening among that group of highly sophisticated clinicians, then it is happening elsewhere."

He speculated that the greatest risk for mortality in using ABC may not be enhanced cardiovascular risk but, rather, the hypersensitivity reaction to the drug, even though use of the HLA screening test for sensitivity should be standard of care.

The ACTG 5202 trial was funded by the National Institutes of Health. GlaxoSmithKline supported an internal review of data. Dr. Pappa is an employee of GlaxoSmithKline. Dr. Sax, Dr. Gulick, Dr. Eron, Dr. De Jesus, and Mr. Huff have disclosed no relevant financial relationships.