Comment by breadwinner

What about Vytorin trial?

Vytorin is a combination of cholesterol-lowering drugs, one called Zetia and the other a statin called Zocor. Because the two drugs lower LDL cholesterol by different mechanisms, the makers of Vytorin (Merck and Schering-Plough) assumed that their double-barreled therapy would lower it more than either drug alone, which it did, and so do a better job of slowing the accumulation of fatty plaques in the arteries - which it did not.

See: https://www.nytimes.com/2008/01/27/opinion/27taubes.html