The drug 3TC should be approved as the first new initial therapy to treat AIDS since the original AIDS drug AZT, scientific advisers told the Food and Drug Administration on Monday.

A combination of 3TC and AZT boosted the immune system of patients and lowered the amount of the HIV virus, which causes AIDS, in their blood.

But more significantly, the drug combination showed more effect in patients who had never taken AZT than in those who have taken AZT alone, as is standard for most patients, manufacturer Glaxo Wellcome said.

The FDA advisers agreed, although they cautioned there are a lot of unanswered questioned that patients must be aware of before choosing to try the combination therapy over AZT alone.

“I am very uncomfortable giving this regimen in a widespread way” because of all the questions, said Dr. Douglas Mayers of the Walter Reed Army Institute of Research in Washington, a consultant to the panel.

All other AIDS drugs sold today are for use after AZT fails and are not used in combination with it.

Early data “support the argument for initial aggressive therapy,” said Glaxo research chief Marc Rubin. “3TC-AZT was consistently associated with greater and more sustained response.”

The experimental drug was discovered by Biochem Pharma of Laval, Quebec, Canada, and licensed in 1990 to Glaxo.