Wednesday, May 8, 2013

Licence for another unproven cholesterol drug - Briffa

The FDA grants licence for another unproven cholesterol drug

Ezetimibe is a drug that lowers cholesterol levels by blocking its absorption from the gut. The drug is available under the brand name Zetia. Doctors can also prescribe ezetimibe in combination with the statin drug simvastatin. This combination medication is sold under the name Vytorin. Both Zetia and Vytorin have racked up billions of dollars in sales. What a shame, then, that neither of them has been found to have any benefit at all in terms of reducing the risk of heart disease, heart attacks, strokes or risk of death.

Zetia and Vytorin are licenced on the basis of their impact on cholesterol levels. The thinking is that LDL-cholesterol must be bad, so anything that reduces it must be good. However, we know from experience that many things that ‘improve’ cholesterol do not bring broad benefits to health. And besides, it’s simply not good science or medicine to assume that a drug has benefits for health based on its impact on what is known as a ‘surrogate marker’ such as cholesterol. I mean, if arsenic reduced cholesterol it still would not make sense for us to swig back arsenic each day, would it?

This seems like perhaps an extreme analogy, but it should be borne in mind, I think, the Vytorin use has in some studies been associated with an increase (not statistically significant) in the thickening of the arteries compared to simvastatin alone. Also, there was some early evidence the Vytorin increased the risk of death from cancer, though some more recent evidence is said to have allayed fears here.

While some doctors continue to prescribe Zetia and Vytorin it’s difficult (for me) to justify this. There is some evidence that since 2008 (when we saw the first of a few negative studies on Zetia/Vytorin emerge) sales of these drugs have fallen considerably, though profit remains considerable. Make no mistake, though, the fact that Zeta/Vytorin is still on the market and was licensed in the first place is seen by some doctors and researchers as testament to the ability of drug companies to bamboozle regulatory authorities such as the Food and Drugs Administration (FDA) in the US. Either that, or the FDA is perhaps putting the needs of drug companies above those of patients.

Against this background, it is interesting to note that Merck (manufacturer of Vytorin) has been for some years attempting to get another similar drug combination passed by the FDA. The drug combines ezetimibe with the statin atorvastatin and has the brand name Liptruzet. As with Vytorin, there exists no evidence that Liptruzet benefits so-called ‘clinical’ outcomes such as incidence of heart disease and stroke.

Now, given all the controversy around Vytorin and the lack of evidence for the benefit of this product, you might imagine the FDA would be keen not to repeat its mistake by granting Liptruzet a licence. Astonishingly, though, the FDA did just this last week.

Now, normally, when a new drug hits the market the press reports parrot the drug company rhetoric about, say, the benefits of the drug and the lives it could save. What is interesting about the press reports on the licensing of Liptruzet is how many of them report scepticism regarding the wisdom of this decision expressed by doctors and researchers. See here for an example.

The piece quotes Steven Nissen, chairman of cardiology at the Cleveland Clinic in the US. According to Dr Nissen, the FDA’s decision to approve the Liptruzet “just doesn’t make any sense.” He is quoted as saying:
I find it astonishing that after all the controversy about ezetimibe the FDA would approve another combination product with a drug that has been on the market for a decade and has not been shown to improve cardiovascular outcomes. It seems like the agency is just tone deaf to the concerns raised by many members of the community about approving drugs with surrogate endpoints like cholesterol without evidence of a benefit for the disease we are truly trying to treat – cardiovascular disease.
And what does Merck have to say for itself? According to spokeswoman Pamela Eisele, Merck is “confident in ezetimibe and in the established relationship between lowering LDL cholesterol and reducing cardiovascular events.”

Merck can be confident all it likes in ezetimibe and its products Zetia, Vytorin and Liptruzet, but the fact is, none of these have been shown to lower ‘cardiovascular events’. My personal opinion is that either Merck is full of idiots or is taking us for idiots. The good news is that the sort of rhetoric spouted by Merck is immediately being recognised by some as having a distinct whiff of b.s. about it.
Reaqd complete article here.

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