Should drug therapies be proven effective before being accepted for general use? Or should they be marketed based on the same sort of unproven claims as herbal remedies, homeopathy, therapeutic touch, and the myriad of other health cons?

Erbitux, a potential new cancer drug by ImClone, and hormone replacement therapy for post-menopausal women are two therapies in the news this week that deserve this scrutiny.

Erbitux is one of a new class of cancer drugs called "epidermal growth factor inhibitors." They're supposed to work by disrupting the transformation of healthy cells into cancerous cells. ImClone and partner Bristol-Myers Squibb hoped to get Erbitux approved by the Food and Drug Administration in early 2002 for the treatment of colon cancer.

In December, though, the FDA refused to consider the approval application for Erbitux, saying it had questions about how ImClone verified that the drug worked. The refusal caused ImClone's market valuation to plummet $2.7 billion.

Although ImClone reported to the FDA that 22.5 percent of 121 colon cancer patients enrolled in a trial responded to treatment with Erbitux, the FDA said more information would be required.

Specifically, the FDA wants ImClone to verify that Erbitux was actually responsible for the reported improvements. It's not good enough to the FDA that Erbitux doesn't do any harm; it must be demonstrated that Erbitux actually does good before receiving approval.

This seems a quite reasonable standard. But not everyone agrees.

The Wall Street Journal editorialized this week that effectiveness is too hard to prove. "Perfect science might demand another 120 cancer patients be tested against a placebo, which means pretending to give them something that saves their lives but in fact doesn't … this is hardly consistent with the Hippocratic injunction to 'do no harm.'"

But since it's not obvious or proven that Erbitux works, it can hardly be said that a genuine clinical trial comparing standard and experimental treatments places anyone's life at risk.

"No harm, no foul" is not the right standard for approving drug therapies. The ongoing flap over hormone replacement therapy (HRT) — including two new studies about the controversy in the last two weeks — exemplifies this point.

Women have used HRT for more than 50 years to ease menopausal symptoms such as "hot flashes." There is no dispute over this use of HRT. Premarin, the most popular HRT, is used by about 12 million women in the U.S. at a cost of about $180 per year.

But through the decades of HRT use, numerous studies jumped to conclusions that women on HRT were healthier and lived longer than women not on HRT. More than 30 studies indicated HRT use after menopause reduced heart disease rates by as much as 50 percent.

Though HRT wasn't approved by the FDA specifically for heart disease prevention, it was nonetheless sold to women for that purpose among others.

When allegations arose that HRT might increase the risk of breast cancer, Premarin's manufacturer responded by emphasizing that heart disease was more of a threat to women than breast cancer: "After age 45, the risk of death from cardiovascular disease outweighs the risk of death from breast cancer. In fact, coronary heart disease kills 233,000 women in contrast to 43,000 women who die of breast cancer in the United States each year."

That may be true, but the older studies on HRT and heart disease are horrendously biased.

As pointed out recently in the Journal of the American Medical Association, women who take HRT tend to be thinner, better educated and more health conscious than women who don't. So HRT users — almost by virtue of their socio-economic status have lower rates of heart disease.

Doctors now are advised against prescribing HRT for the purpose of preventing heart disease because there's no proof it works.

Something more unsettling may be in store. Some research reports that HRT may actually increase the risk of heart attack for some women.

How many doctors and women have been misled for decades and at what cost and false hope about a mythical benefit? And now they should perhaps even be informed of a serious risk. Women, beware.

Proving the efficacy of drug therapies certainly is difficult for chronic diseases such as cancer and heart disease. Good studies take years — if not decades — and are very expensive.

That doesn't mean proof of efficacy or at least some reasonable indication of it shouldn't be required. If we don't insist on an evidence-based approach to conventional medicine, it may as well be lumped in with the ranks of other quackery.

Steven Milloy is the publisher of JunkScience.com, an adjunct scholar at the Cato Institute and the author of Junk Science Judo: Self-defense Against Health Scares and Scams (Cato Institute, 2001).

Respond to the Writer