Company-Funded Drug Trials Favor Company’s Treatments

Studies funded by pharmaceutical companies usually find that the best drug is the one made by the companies sponsoring the trials, according to a study in the American Journal of Psychiatry, the Washington Post reports.

Psychiatrist John Davis and colleagues analyzed all publicly available studies funded by the pharmaceutical industry that examined the effectiveness of five new antipsychotic drugs. They found that nine in 10 of the studies showed that the best drug was the one made by the company that funded the study.

For example, Eli Lilly recently funded five studies that compared its antipsychotic drug Zyprexa with Janssen's Risperdal; all five studies say that Zyprexa is a superior treatment for schizophrenia. When Janssen sponsored its own studies comparing the drugs, it found that Risperdal was superior in three out of four.

"On the basis of these contrasting findings in head-to-head trials, it appears that whichever company sponsors the trial produces the better antipsychotic drugs," Davis and colleagues write.

In a federally funded study of antipsychotic drugs, researchers found that clozapine and another low-cost drug that is no longer under patent, were more effective at treating schizophrenia than all other drugs currently under patent.

According to Davis, there are several ways in which drug companies can produce results that favor their own products. For example, they can use low doses of the competitors' drugs or choose statistical methods that favor their drugs. Most trials also enroll patients with more straightforward problems than doctors generally see in practice.

According to experts, most areas of medicine rely on industry-sponsored studies to test the effectiveness of drugs, but biases can be magnified in fields where the goal of studies is to demonstrate symptomatic improvement instead of cures, allowing for looser interpretation of findings, the Post reports.

Drummond Rennie, deputy editor of the Journal of the American Medical Association, said, "A perfectly independent agency has to be set up that says, 'Here are the areas where trials must be done. There will be two classes of trials -- the believable ones and the nonbelievable ones.'"

Sara Corya, medical director of neuroscience at Eli Lilly, said conflicting results from trials do not negate each other and can help doctors understand the strengths of different medications.

Mariann Caprino, a spokesperson for Pfizer, said, "The reality is that even in head-to-head comparisons, study results will differ for a variety of reasons, some transparent, some opaque. What this all means is there is no substitute for the judgment and experience of the clinician in selecting among a fortunately broad palette of medicines" (Vedantam, Washington Post, 4/12).