Merck's Vytorin, Zetia Cholesterol Drugs Questioned : The Two-Way If it turns out that many patients with high cholesterol could benefit more by taking the relatively inexpensive B-vitamin niacin than the much pricier cholesterol lowering drugs Vystorin and Zetia, that would certainly be a good news for those pa...
NPR logo Merck's Vytorin, Zetia Cholesterol Drugs Questioned

Merck's Vytorin, Zetia Cholesterol Drugs Questioned

If it turns out that many patients with high cholesterol could benefit more by taking the relatively inexpensive B-vitamin niacin than the much pricier cholesterol lowering drugs Vystorin and Zetia, that would certainly be a good news for those patients and bad news for the maker of the drugs Merck & Co.

Research unveiled by investigators Monday at the American Heart Association conference in Orlando points to that tantalizing possibility.

As NPR's Richard Knox reported for the network's newscast:

The new study looked at ezetimibe, the main ingredient in the drugs Zetia and Vytorin, compared to a B-vitamin called niacin that costs far less. Patients with heart disease got one or the other along with a conventional cholesterol-lowering statin drug.

Those who got ezetimibe had much lower levels of LDL or "bad" cholesterol. But those who got cheaper niacin actually had clearer arteries...

... It's the third recent study to cast doubt on the effectiveness of Zetia and Vytorin. Merck, the drugs' maker, says doctors and patients should wait for the results of a much larger study expected about two years from now.

Below is an artfully done Vytorin ad that sold the notion that the drug was effective in lowering two sources of bad cholesterol: diet and genetics.

While acknowledging the limitations of the research presented Monday, for instance, the small group of patients (208) whose data resulted in the conclusions drawn, two experts on the role cholesterol plays in vascular disease wrote in an editorial in the New England Journal of Medicine that the research pointed to the benefits of niacin over ezetimbe for certain patients:

Together, the results available to date provide support for the concept that the use of statins to reduce LDL cholesterol to target levels with the subsequent addition of a drug to raise HDL cholesterol levels (niacin), rather than a drug to lower LDL cholesterol levels (ezetimibe), is a more effective treatment for patients at high cardiovascular risk.

Sales of Vytorin and Zetia have been huge for Merck. The company reported 2008 sales of $4.9 billion for the two drugs. Vytorin is a combination of a cholesterol-lowering drug called simvustatin and ezetimibe which works to lower blood cholesterol levels through a different process than statins. Zetia is ezetimibe by itself.

Sales of the Merck drugs have declined since January by nearly $500 million, according to reports.

With the stakes so high, Merck is aggressively responding to the latest study. An excerpt from a Merck statement:

ORLANDO, Fl., Nov. 15, 2009 -- At the American Heart Association meeting today, Merck & Co., Inc. said it is confident in the safety and efficacy profiles of ZETIA?? (ezetimibe) and VYTORIN?? (ezetimibe/simvastatin), and issued the following comment in response to misinterpretation of results from a small 200-patient imaging study called ARBITER 6.

"The results of the small ARBITER 6 study do not, in any way, change our view of ZETIA and VYTORIN as effective medicines for fighting high LDL cholesterol," said Peter S. Kim, Ph.D., president, Merck Research Laboratories. "Nothing from this study, which a New England Journal of Medicine editorial says has 'several limitations,' changes the well established understanding that lowering LDL cholesterol is the primary target of therapy according to the guidelines. ZETIA and VYTORIN, when used as a supplement to a healthy diet, are effective in reducing LDL cholesterol," said Dr. Kim. "We encourage patients to continue taking their medication as prescribed by their physicians, and of course to speak to their physician if they have concerns."

Meanwhile, Abbott Laboratories stands to gain since it makes a drug based on vitamin B3 called Niaspan. Abbott issued a statement too:

Orlando, Florida -- Results from the investigator-initiated ARBITER 6 - HALTS study showed patients at high cardiovascular risk had significant regression of atherosclerosis after 8 and 14 months of therapy with Abbott's Niaspan?? (niacin extended-release tablets) plus a statin, the study's primary endpoint. In a pre-specified secondary endpoint of the study, treatment with Niaspan plus statin also resulted in significantly fewer major adverse cardiac events, (or MACE, a composite endpoint consisting of heart attack, myocardial revascularization, admission to the hospital for an acute coronary syndrome, and death from coronary heart disease), as compared to ezetimibe plus a statin.

The study was stopped early after a pre-specified interim analysis was conducted on 208 patients who had completed treatment and had undergone final ultrasound imaging of the carotid artery to measure the impact of treatment on atherosclerosis. Atherosclerosis is fat build-up in the arteries and in the early stages it can be found inside the lining of the arteries, known as intima media thickness (IMT). HALTS measured IMT in the carotid artery.

"The ARBITER 6 - HALTS study is the first study showing that HDL-raising with Abbott's Niaspan on top of statin regresses atherosclerosis compared to an LDL-lowering strategy," said Eugene Sun, M.D, vice president, Global Pharmaceutical Development, Abbott. "These data reinforce the importance of looking beyond LDL treatment targets to address other lipid parameters."