The German government should push for an EU regulation making it compulsory to register and publish within tight deadlines the results of all clinical trials, says the country’s health technology assessment body, the Institute for Quality and Efficiency in Health Care (IQWiG).

The Institute is smarting from a tussle with Pfizer over undisclosed study data on the company’s antidepressant reboxetine (Edronax), whose benefits IQWiG was assessing along with those of two other antidepressants, mirtazapine (MirtaLich, Winthrop Arzneimittel) and bupropion XL (Wellbutrin XL, GlaxoSmithKline).

According to IQWiG, this process was “greatly hindered” by Pfizer, which refused “for a long time” to make trial data on reboxetine available to the Institute and only caved in “when put under public pressure”.

The complete dataset showed that some 5,100 patients in total were treated with reboxetine in the 17 trials included in the benefit assessment, IQWiG noted. Yet “sufficiently transparent” published data were available for only 1,600 of those patients.

“Thus, the results of approximately two thirds of the patients are missing in the publicly available literature,” IQWiG commented. “The published results suggest a benefit, but this cannot be proven when all the data are considered.”

As the Institute observed, it concluded a basic agreement on the release of unpublished clinical trial data with the German Association of Research-based Pharmaceutical Companies (VFA) as early as 2005. And in January of that year the various regional associations for the international pharmaceutical industry announced a voluntary commitment to disclose information on clinical trials.

However, these commitments cannot be relied on, IQWiG complained. In recent years, “companies have repeatedly refused to provide the Institute with study documents required for the benefit assessment of drugs. Frequently, clinical trial registries, which have been set up in recent years, do not contain these data either”.

By concealing available study data, manufacturers are “depriving patients and doctors of the opportunity to make an informed decision on different therapy options”, said IQWiG director Peter Sawicki. They are also hindering the work of institutions such as IQWiG, which provides the German Federal Joint Committee (G-BA) with a scientific basis for its decisions on drug reimbursement.

Moreover, non-disclosure amounts to “cheating” participants in clinical trials, who “put themselves at risk by taking part in experiments both voluntarily and altruistically”, Sawicki argued. Through their participation and the publication of trial results, these people “want to help others who are ill. This is a prerequisite of their consent to participate in drug trials”.

In the US, the obligation to publish the results of clinical trials has been clearly enshrined in law since 2008, Sawicki pointed out, adding: “We need a comparable, definite and transparent implementation for Europe as soon as possible”.