Advera Health Analytics: Merck statins linked to more muscle side effects than rest of class

Statins are tried-and-true moneymakers, but they also come with their own set of safety concerns. Cardiovascular problems linked to the meds are nothing new, and scientists recently highlighted potentially alarming side effects including amnesia and mental decline.

But a pacing of side effects data shows these neurological side effects are not turning up as frequently in postmarketing safety data. And muscle-related side effects, which are commonly linked to the drugs, show up more often in three Merck ($MRK) products than in the rest of the class.

That's the word from healthcare informatics company Advera Health Analytics. The firm sifted through FDA postmarketing safety reports, and compiled data on side effects for companies producing statin drugs. Advera's report found that Merck's Zocor, Mevacor and Vytorin were associated with more muscle-related side effects than other drugs in the class such as Pfizer's ($PFE) Caduet, AbbVie's ($ABBV) Simcor and AstraZeneca's ($AZN) blockbuster Crestor.

For example, Zocor had 4275 reports of myalgia, 632 reports of myopathy, and 3552 cases of rhabdomyolysis, a condition commonly linked to statins that involves the breakdown of muscle tissue. In comparison, Caduet had 59 reports of myalgia, 5 reports of myopathy and 12 reports of rhabdomyolysis in postmarketing data. And AbbVie's Simcor was linked to 365 reports of myalgia.

Pfizer and AbbVie are standing by their products' safety. "Caduet has been evaluated for safety in 1,092 patients in double-blind placebo-controlled studies," a Pfizer spokesman told FiercePharma in an email. "In general, treatment with Caduet was well tolerated and adverse reactions have been mild or moderate in severity."

AbbVie is singing a similar tune. The company said it was "inappropriate to comment" on Advera's findings that Simcor turned up fewer reports of side effects than Merck's products, a spokesman told FiercePharma in an email. And as for the 365 cases of myalgia, the condition "is contained in the labeled precautions and warnings," the company said. "Patients should consult with their physician regarding the most appropriate treatment option available to them."

While there's "still a lot of controversy" about whether muscle side effects stem from the drugs or from a patient's deteriorating condition, the firm still found the link between muscle-related AEs and increased reports for Mevacor, Zocor and Vytorin, "illuminating," Advera Health Analytics VP of scientific affairs Keith Hoffman told FiercePharma.

Keith Hoffman

"There are some people who believe the same amount of side effects would happen on a placebo and some who disagree," Hoffman said. "It's a continuing topic of debate and what we've provided here is a separation between the three drugs, and the other three drugs that show less reporting."

Still, Merck is standing by its drugs, saying that reports submitted under the voluntary reporting system "often have incomplete medical and drug histories and unsubstantiated diagnoses," the company told FiercePharma in a statement.

"Merck is vigilant in monitoring adverse event reports (AERs) from its clinical trials and post marketing reports, and files regular reports with the FDA and other regulatory agencies for all of Merck's medicines including its cardiovascular portfolio," the company said. "The labels for (the drugs) reflect the well-established efficacy and safety profiles of both medicines, and are based on ongoing assessments by Merck and regulatory agencies. Merck continues to appropriately communicate the labeling on these products to physicians, patients and payers around the world."

Side effects that Advera expected to turn up in droves did not appear often in the firm's analysis, Hoffman said. There's a growing body of evidence that links statins with cognitive decline and dementia, but Advera did not find a strong link between cognitive side effects and statins, he said. Lipitor turned up the most reports of amnesia and dementia, with 1014 incidents and 130 incidents, respectively.

"If there was a strong effect for cognitive decline out there for these drugs, we'd see higher numbers in post-marketing reports," Hoffman said.

One potential side effect to keep an eye on is Type 2 diabetes, he added. Lipitor was linked to 7,061 reports of Type 2 diabetes mellitus in Advera's report, and Crestor was tied to 557 reports of the disease. Those numbers could come as bad news to AstraZeneca, which will face U.S. generics for Crestor in May 2016 and is already dealing with competition from off-patent Lipitor.

But almost all the cases for Lipitor and Crestor regarding cognitive decline were filed by non-healthcare professionals, Hoffman noted, which is unusual in postmarketing reporting. While it "gives us pause in extrapolating the data," the company will "wait for future reports to come" to flesh out the safety signals, he said.

AstraZeneca declined to comment to FiercePharma about Crestor's postmarketing safety.

- get the Advera analysis

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