High hopes for new Aids treatment mernt

The Aids virus, HIV, appears to have been cleared from the blood and plasma of nine infected patients treated with a cocktail of three drugs, the 11th international conference on Aids, meeting in Vancouver, was told yesterday.

News of the study has been circulating among Aids researchers for some time but its details were only released yesterday. It has helped fuel hopes for drugs that not only slow the advance of the virus, but eradicate it.

Early results indicated that a triple therapy regimen of Norvir, AZT, and 3TC had rendered the nine men newly infected with HIV aviremic - meaning their blood and plasma were free from the virus, said Dr Martin Markowitz, lead investigator on the study.

"While this is very encouraging news, it's important to note that these results cannot yet be called a cure," said Dr Markowitz, of the Aaron Diamond Aids Research Centre, in a statement. "We don't know if the virus will rebound if patients were to cease the regimen. Studies are under way to find the answer to this question."

As little as six months ago, doctors were stuck with the knowledge that while they could slow the advance of Aids with drugs like AZT, the virus was usually able to develop resistance and progress.

But a new class of drugs, called protease inhibitors and which attack an enzyme critical to the HIV's reproduction, brought a note of cautious optimism from experts at the conference. "People haven't been this excited for a long, long time," Dr Martin Schecter, conference co-chairman, said.

Norvir is manufactured by Abbott Laboratories, and was cleared for distribution by the US Food and Drug Administration in March. AZT and 3TC are products of Glaxo-Wellcome, and are already available in the US. Two other international pharmaceutical giants, Hoffman-La Roche and Merck, have also rushed protease inhibitors to the market.

The study involved 12 patients, but one developed an intolerance to all three drugs and two others discontinued the therapy. Treatment began within 90 days of infection and consisted of 600mg Norvir twice daily, 200mg AZT three times, and 150mg 3TC twice daily.

The study was launched in July, and today no trace of the virus can be found in the men's bodies. But the question remains as to whether the HIV will somehow bounce back when treatment is discontinued.

A test weaning period is planned, and experts warn it is too early to talk of a "cure" on what they say is limited and incomplete research. Hopes have risen before to be shot down.

The drugs' effectiveness seems to rely on elaborate cocktails and heavy daily doses that must be strictly adhered to. Aids activists said the expense - up to $16,000 a year - puts them beyond the reach of most of the 21 million around the world estimated to have contracted the virus.