Planting Seeds, Drug Industry Harvest

Do seeding trials cause doctors to prescribe more drugs from the company sponsoring the trial? Seeding trials, for those not familiar with the concept, are clinical trials on drugs that have already been approved by the FDA. Companies claim they are designed to show the drugs work for different indications, some of which is legitimate. But mostly it's a way to introduce doctors and their patients to me-too drugs entering a crowded field. How else can one explain a trial designed to show that a pain pill works not only on elbows, but on knees, too?

That’s why a new study out of Denmark appearing in today’s Journal of the American Medical Association offers some insight into this phenomenon. The authors compared the records of patients in post-marketing clinical trials for an asthma inhaler to patients in normal practice diagnosed with asthma. They found the prescription rate in both groups was almost exactly the same (about 70 percent), but that physicians in the trials increased their use of the sponsors’ drugs from 52.9 percent to 58.7 percent after two years while those in routine practice actually saw the use of those drugs decline slightly (52.8 percent to 51.9 percent).

This evidence suggests that when doctors sign their patients up to participate in a seeding trial, the drug companies get what they pay for. An excellent accompanying editorial (subscription required) by Bruce Psaty and Drummond Rennie reviews the voluminous literature on the drug industry’s influence over physician prescribing patterns, and concludes:

Practicing physicians and disinterested scientists need to recognize and acknowledge these forms of potential influence by the pharmaceutical industry. Agreeing to work as an investigator in industry-sponsored trials may represent a commitment to an effort that is more or less a scientific endeavor and, at the same time, a marketing initiative.

More importantly, the scientific rationale for launching thousands of small short-term trials remains unclear. The health of the public would be better served by the conduct of fewer small short-term studies and more well-designed large long-term trials. . . that fully address the health risks and benefits of pharmacological therapies used for chronic conditions.