Drug Companies Keeping Secrets: Negative Clinical Trial Data

Author:  Ramlagan Nadia

Date:  April 2008

The formidable thought of drug companies withholding scientific information for self-interest has been in the minds of several experts and members of Congress lately. Major drug companies Merck & Co. and Schering-Plough are under tough scrutiny after the delayed release of ENHANCE clinical trial results. The trial studied the effects of cholesterol-lowering drugs Vytorin and Zetia.

Almost 2 years after completion of the ENHANCE trial, the companies recently decided to release the full results of the study, which provide evidence that Vytorin-a combination of drugs simvastatin and Zetia, had no greater effect on lowering cholesterol than simvastatin alone in preventing the buildup of arterial plaque.

Furthermore, a panel of five medical experts at the American College of Cardiology (ACC) meeting in March 2008 advised doctors to prescribe drugs containing statins (simvastatin belongs to the class of drugs called statins) over Vytorin or Zetia. Both statin and Zetia (which is primarily composed of a compound called ezetimibe) lower levels of LDL or the bad type of cholesterol, but each has a different mechanism of doing so.

Statins are compounds that limit the amount of cholesterol the body produces, whereas ezetimibe prevents the body from absorbing cholesterol found in foods. The main difference between the two drugs is that statin has the additional ability to reduce heart attacks and death. Atherosclerosis is a disease that causes plaque to build up on the insides of the arteries. This reduces blood flow to the organs, often causing heart attacks.

According to a statement from the ACC, "The results of the trial show no benefit from the combination of ezetimibe (Zetia) and simvastatin (sold together as Vytorin) over simvastatin alone in terms of affecting the rate of atherosclerosis progression."

The companies contend that full disclosure of the ENHANCE trial was postponed due to unresolved problems analyzing data, and not for continuing profits from sales.

Experts and Senator Charles E. Grassley (R-Iowa) are highly skeptical of Merck/Schering Plough's motives, and contend that the companies deliberately held back negative data from the clinical trial for financial and marketing purposes.

The controversial trial is at the heart of a larger debate on how a company's decision to withhold data affects the public. Drug companies have an ethical duty to disclose the full contents of clinical trials. Without complete information about a drug, medical professionals cannot make knowledgeable decisions or recommendations about potentially helpful new drugs, nor can patients be assured that they are paying a justifiable amount for their prescriptions.

Written by Nadia Ramlagan

Reviewed by Maria Huang, Pooja Ghatalia

Published by Pooja Ghatalia.