On January 22, Schering-Plough and Merck announced they would briefly suspend Vytorin ads after the uproar over the disclosure the previous week of the Enhance trial. A spokesman blamed “mischaracterization and misinterpretation” of the study results, which found Vytorin failed to show any benefit over the much cheaper Zocor in reducing plaque in the carotid artery, and even showed a statistically insignificant buildup, although it did a better job of lowering LDL in a small group of patients with inherited high cholesterol.

However, FDA officials had already begun signaling that consumer ads and promotional materials distributed to docs had to be changed. Although the agency had noted certain issues in 2005, they committed an oversight that now had to be corrected - in a prior study, Zocor reduced the risk of heart attack, stroke and heart procedures, but Zetia has not been shown to prevent such outcomes. Vytorin, by the way, combines Zocor and Zetia. And so in a January 23 letter to the drugmakers, the FDA noted that “Vytorin has not shown any additional cardiovascular benefit compared to using (Zocor) alone.”

The FDA tells the drugmakers that its advertising is “misleading because the pieces do not include contextual information disclosing a limitation to the efficacy of Vytorin regarding clinical outcomes benefits.” And the agency wants the advertising to note, in “consumer-friendly language,” that it should be clear Vytorin had “not been shown to provide any additional cardiovascular benefits” when compared with Zocor alone.

This is rather interesting: the FDA required the drugmakers to advertise that Vytorin was no better than the less expensive Zocor. The previous ad campaign was widely criticized for fueling prescriptions despite a lack of data showing the drugs actually reduce the risk of heart attacks and strokes. We’re curious to see what the next ad campaign will look like and how Schering-Plough, Merck and its ad agencies will finesse this point.

To see the rest of the letter, please keep reading…