TRENTON, N.J. — Investors continued dumping shares of Merck & Co. and Schering-Plough Corp. on Tuesday, a day after their cholesterol-drug partnership took a hit from somewhat negative results of a controversial study, but some analysts called the worries overblown.
The study examined how much one of their cholesterol pills, Zetia, reduced plaque buildup in arteries supplying blood to the brain, compared with their heavily advertised combo pill, Vytorin.
Vytorin combines Zetia and Merck’s older cholesterol drug, Zocor, now available as a cheaper generic pill.
Instead of showing Vytorin did a better job, the study, called ENHANCE, found no meaningful difference between the two pills, apparently indicating Zetia gave no benefit. However, some Wall Street analysts said flaws in the study’s design made it difficult for Vytorin to come out on top and cited other evidence of Vytorin benefits.
Publicity about the results, released Monday, pushed Schering-Plough shares down 8 percent Monday and another 6.8 percent Tuesday, to $23.78. Meanwhile, Merck shares dipped 1.3 percent Monday and another 2.7 percent Tuesday, to $58.18.
“I firmly believe this is an overreaction,” Lehman Brothers pharmaceuticals analyst Tony Butler said Tuesday.
