The reluctance of some pharmaceutical companies to supply placebos for independent clinical trials is undermining studies not dictated by commercial objectives, two Danish researchers claim.

“We believe that this could be a major way for the pharmaceutical industry to control scientific information about their drugs,” contend Mikkel Christensen and Filip Knop from the University of Copenhagen in a letter to the 7 January issue of The Lancet.

Christensen and Knop cite an “example known by us” in which an unidentified drug company was approached by researchers for placebo medication, in the form of an injection pen for diabetics, to support an independently financed trial of a marketed product.

The company concerned asked for a full study protocol, which was scrutinised by “an opaque system of evaluation committees”, Christensen and Knop write. After more than six months, they say, the company finally agreed to supply the placebo devices on condition that the protocol was changed in line with its suggestions.

The researchers were “also obliged to allow the company access to the resulting trial report for four weeks before submission for publication”.

In a second case described by the Danish researchers, another unidentified drug company “charged an extraordinary amount of money for providing a simple placebo tablet, effectively preventing the planned clinical trial from going ahead”. In another instance, a company simply “refused to deliver the placebo”, they claim.

In these circumstances, the only alternative – short of compromising the trial with an unblinded design – is to have the placebo manufactured elsewhere, Christensen and Knop add. This can be “extremely costly and cumbersome – or even impossible”.

Strong need

Industry-sponsored research “often focuses on profitable areas and future profits instead of areas where important health improvements could result”, the authors comment. Industry’s reluctance to pursue relevant head-to-head trials also underlines the strong need for independent clinical research, they say.

“In our opinion, the pharmaceutical industry has an obligation to provide placebo to match their marketed drugs without prior assessment and approval of protocols,” Christensen and Knop argue.

“Unfortunately, the present situation shows that, without a legal obligation to provide placebos to match their marketed drugs, the pharmaceutical industry has de-facto control over drug trials.”