Why the new indication for Vytorin and Zetia should not be approved
I have a guest post up at Merrill Goozner’s blog explaining why Merck’s application for a new indication for its drugs Vytorin (simvastatin/ezetimibe) and Zetia (ezetimibe) should not be approved. The proposed indication is for the reduction of major cardiovascular events in patients with chronic kidney disease and is based on the results of the SHARP trial. However, because SHARP compared the combination of simvastatin and ezetimibe with placebo — there was no simvastatin arm — we have no way of knowing if ezetimibe contributed anything to the result. The FDA requires that combination drugs have additive effects over either drug alone. Merck has not shown that ezetimibe contributed anything to the effect in SHARP, so the new indication should not be approved.
Addendum January 25, 2012: Merck issued a press release today stating that the FDA did not approve the new indication. “Because SHARP studied the combination of simvastatin and ezetimibe compared with placebo, it was not designed to assess the independent contributions of each drug to the observed effect; for this reason, the FDA did not approve a new indication for VYTORIN or for ZETIA® (ezetimibe) and the study’s efficacy results have not been incorporated into the label for ZETIA.” The SHARP results were incorporated into the Vytorin label (see pages 27-28).