Merck wins FDA nod for new Zetia-Lipitor combo, despite lack of outcomes benefit

Merck will soon launch a new cholesterol combo that melds its Zetia drug with generic Lipitor. The Zetia-plus-statin approach isn't new, of course; Merck ($MRK) already sells Vytorin, a combination of Zetia and its own off-patent statin Zocor, known generically as Simvastatin. And as experts note, the new drug--Liptruzet--comes with similar questions about its real-world benefits.

In announcing the approval, Merck touted the fact that Liptruzet lowered patients' cholesterol levels in trials better than generic Lipitor alone. The company also acknowledged that the drug didn't actually reduce trial participants' chances of developing heart disease. "No incremental benefit of Liptruzet on cardiovascular morbidity and mortality over and above that demonstrated for atorvastatin has been established," Merck said in a statement.

That result harks back to the much-maligned Enhance trial, which found that Vytorin was no better than Zocor alone at keeping away arterial plaques. The lack of outcomes benefits, despite the improvement in "bad" cholesterol numbers, stirred up debate over LDL cholesterol levels as a surrogate endpoint for drug development.

Now, with no outcomes benefit shown for Liptruzet, some question why the FDA would approve it. "This is extremely surprising and disturbing," the Cleveland Clinic's Dr. Steven E. Nissen told The New York Times. In Forbes, Nissen expanded on the idea, saying he found it "astonishing" that the FDA would approve another Zetia combination, given that Zetia itself hasn't proven effective at improving cardiovascular outcomes, even after its decade on the market.

"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," Nissen told the magazine.

But the FDA maintains that high LDL levels are a known risk factor for heart disease. "Liptruzet is a combination of two currently marketed drugs that effectively lower elevated levels of LDL cholesterol," an agency spokeswoman told the NYT. And Merck says Liptruzet is a good option for patients who haven't been able to lower their LDL levels in other ways.

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For more:
FDA rejects Merck's new combo cholesterol drug
Pfizer sues Merck to block Lipitor/Zetia combo pill
Pfizer, Teva settle rancorous Lipitor fight in U.K.