Leading Article: The business of Aids

YESTERDAY'S fall in the share price of Wellcome, a leading British drug firm, is a reminder that the prevention and treatment of Aids is not just a scientific and social issue, but big business, too. When early results from a study in 1989 suggested that a Wellcome drug was a promising new treatment for the virus, investors rushed to buy its shares - for they knew how richly the firm would profit by selling its drug among the virus's 10m sufferers worldwide.

The opposite happened yesterday. A newer study whose preliminary results were released on Thursday suggests that the drug, known as AZT in the United States and Retrovir in Britain, has no effect on those who have the human immunodeficiency virus (HIV) but have not yet developed the full-blown symptoms of Aids. Over three years, the researchers found, patients given AZT had a lower survival rate than patients given a placebo.

Aware of the risk to its share price, Wellcome was quick to insist that AZT is still believed to be helpful to patients who have progressed to Aids itself - and reminded doctors that if used with another drug rather than on its own, AZT may still work for patients who carry the virus but do not yet have symptoms. Investment analysts observed dryly that six out of ten patients who are now paying for AZT will be unaffected by the study's findings, so the damage to Wellcome's profit and loss account will be limited.

On reading such reactions it is tempting - but misguided - to rail at the cold-blooded nature of markets. The money and human resources that pharmaceutical firms devote to research into treatments and cures for Aids is vastly greater than governments on their own could afford. Companies must be allowed to patent their drugs, and to sell them at high prices, if they are to have any incentive to do Aids research.

But the results of the latest study raise again a question that governments have asked themselves for years: when and how to let new drugs on to the market. Drugs must be shown to be effective before they can be sold, for otherwise patients will be gulled by the unscrupulous into paying for quack remedies that cannot possibly do them any good.

The question is where to draw the line. If the regulators move too slowly and demand excessively high standards of proof that a drug works, then patients who might have benefited from it will die in the meantime. If they move too fast, then patients (or their insurers) will pay thousands of pounds for treatments that not only do them no good, but make their lives worse with unpleasant side-effects.

This issue is common to all drugs. But in the case of Aids treatment, it has become vexed and politicised. Those who lobbied on behalf of Aids victims in the United States complained angrily in the late 1980s that regulators at the Food and Drug Administration (FDA) in Washington - an organisation that has had a reputation for considering drugs carefully ever since it refused to licence the sale of thalidomide in the US - were dragging their feet.

Under extreme pressure, the government and its scientists made a concerted effort to speed up the approval of new Aids drugs. AZT itself, which has become by far the most popular Aids treatment, made its way through the process in a record 105 days. Then new 'accelerated approval' procedures were put in place. The rules defining what drug trials had to prove were loosened; companies were told that they could give untried drugs to patients in a 'parallel track' to controlled experiments, rather than waiting until the experiments were over; and evidence from animal tests carried out abroad that had previously had to be done again in America was accepted.

As a result, nine Aids drugs now on the American market were approved on average in seven months each, rather than the two years common with other sorts of drugs. In theory, these fast-track methods are open to treatments for cancer and Alzheimer's disease, too. In practice, they have been used to rush only Aids treatments on to the market.

This week's study is likely to raise claims that the regulators were too hasty in approving AZT: it suggests that tens of thousands of people with HIV but no Aids symptoms have been paying handsomely to take a drug that might as well have been aspirin.

There was nothing wrong with the early study that was done in the US. Researchers there found after 24 weeks of testing that 17 people who were being given a placebo died, while only one who was taking AZT did. The doctors felt that it would be unethical to withhold AZT from the surviving placebo patients, and therefore called off the rest of the test. It is only because the second test, whose results came out this week, lasted so much longer that those promising early results are now overtaken.

Officials at the FDA insist they have been very careful in the way they loosened the approval rules for AZT and other drugs. They say that only patients who have nothing to lose - either because they are in imminent danger of dying, or because they cannot tolerate other treatments - are given access to unproven drugs released under the fast-track system. But that was evidently not the case with AZT: many of the patients who received it had contracted the HIV virus but could still have been years away from developing the more worrying full-scale symptoms of Aids.

Regulating the supply of new drugs on to the market will never be a popular job. Patients, doctors and drug companies, often bitterly opposed to one another on other issues, will unite to demand that new treatments be made available more quickly than regulators would like. In most cases where regulators fight for the public good, they have allies; when the issue is drugs, they can expect thanks only later.

In the case of AZT, the risks of premature release should not be exaggerated: what has happened will probably advance, rather than set back, the search for an Aids cure. But the drug's speedy release may shorten the lives of desperate patients by raising the virus's resistance earlier than desirable; and it may cost patients, their insurers and the taxpayers large sums of money. That is what drug regulators are there to prevent. The lesson of this week is that they should not allow themselves to be persuaded by pressure groups to relax their normally rigorous standards.