Abacavir

FDA: Test before giving GSK med

Tracy Staton — Thu, 24 Jul 2008 10:30:46 -0400

Personalized medicine, here we come--at least that's the message in two genetic-testing developments today. First, the FDA is advising docs to screen HIV patients for a particular genetic variant before prescribing abacavir, a GlaxoSmithKline anti-AIDS med sold under the brand name Ziagen and as part of the combo treatments Trizivir and Epzicom. That's because people with that genetic variation are at a far higher risk of a severe allergic reaction.

Though that risk was first reported several years ago, it was only recently quantified in a clinical trial. The genetic test will be recommended in a "black box" warning on abacavir labeling. With this move, abacavir becomes one of only a handful of meds for which the FDA has recommended genetic screening--but we can expect more to come.

Second, a new study tagged a particular variant with statins' most serious side effect. People who have that genetic variation were five to 17 times more likely to develop muscle pain and weakness--which can lead to muscle breakdown, kidney failure and death--when taking the cholesterol-lowering meds. The finding could lead to a predictive genetic test, which could help doctors know which patients can tolerate the higher doses that are increasingly common amongst statin-users.

- read the abacavir news from the New York Times
- check out the Washington Post statin story

Did GSK ignore early abacavir warning?

Mon, 12 May 2008 06:59:55 -0400

Back in 2005, Swedish pharma monitors raised a red flag on the HIV fighter abacavir and its possible link to heart attacks, The Independent is reporting. Thirty-four patients taking abacavir had heart attacks, the Uppsala Monitoring Centre told GSK in May 2005, the newspaper says. Nothing was said publicly, however, until April 2008.

You'll recall that last month, The Lancet published a study showing that abacavir patients had almost double the risk of heart attack as did patients taking other AIDS drugs. Independent scientists said at the time that the data wasn't strong enough to prove a causal link, but that the link was too pronounced to ignore. The same scientists also questioned the data GSK used to back up its pooh-poohing of the link. At the time, the company called the study's findings "unexpected."

- read the story in the Independent

Lancet: Glaxo HIV med boosts cardiac risk

Wed, 02 Apr 2008 07:59:56 -0400

A leading AIDS med made by GlaxoSmithKline carries nearly double the risk of heart attack compared with other anti-HIV meds, according to a new study published by the Lancet. Abacavir--which recently was anointed a "preferred choice" for first-time AIDS treatment--stepped up heart attack risk by 90 percent, the 33,000-patient study showed. EU drug regulators asked GSK for more data on the drug so they might better analyze the potential risk.

AIDS treatment experts said that, because the study didn't identify a biological cause for the increased risk, they might not choose to switch patients off the med. Plus, the patients most likely to develop heart problems with abacavir are those with underlying medical problems such as diabetes and high blood pressure--but the alternative drug can cause kidney problems in those patients.

GSK sped out a statement in response, saying that analysis of its own data on 9,600 patients show no increased risks (But the EMEA notes that these studies weren't designed to check for cardiac risks). Even if the heart attack risk were doubled, it would still be quite low, the company said: 6 per 1,000 patients versus 3 per 1,000.

- see GSK's statement
- read the European Medicines Agency release
- get more from the BBC
- find this story from the San Francisco Chronicle
- check out the MarketWatch news on the EU

ALSO: India's Cipla makes its anti-HIV meds by circumventing other companies' patents, making it the largest AIDS drug supplier in the world. Supporters say CEO Yusuf Hamied has saved countless lives by making meds affordable; critics call him a pirate and opportunist. Report | Report

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