Significant 30 Percent Increase in Relative Risk of Cardiovascular Events or Death

PfizerAn observational study of a large United Kingdom primary care database showed that switching patients from Pfizer's Lipitor® (atorvastatin calcium) Tablets to simvastatin was associated with a 30 percent increase in the relative risk of major cardiovascular events, including heart attacks, strokes and certain types of heart surgeries, or death compared to patients who remained on Lipitor therapy.

This analysis was presented today at the European Society of Cardiology Congress 2007 and is also in press at The British Journal of Cardiology.

The data, which included records from October 1997 to June 2005, were generated from a retrospective analysis of a medical database of anonymous patient records entered by general practitioners in the United Kingdom known as The Health Improvement Network (THIN). The analysis included 11,520 patients (2,511 patients who had taken Lipitor for six months or more and were switched to simvastatin vs. 9,009 patients who were taking Lipitor for six months or more and then remained on Lipitor therapy). Reasons for switching were not available from the database. Since patients were not randomly assigned to each group, the two treatment groups were matched based on certain risk factors and statistical adjustments were made to address any residual imbalances. As with all observational studies, the findings should be regarded as hypothesis generating.

"Today, many health care payors including governments and managed care companies are encouraging patients who are well-established on one therapy to switch to a different statin therapy," said Dr. Michael Berelowitz, senior vice president of Pfizer’s global medical division. "This study raises concerns about those policies. It suggests the potential for poorer cardiovascular outcomes associated with switching patients from established Lipitor therapy to simvastatin."

A secondary analysis of the same data showed that patients who were switched from Lipitor to simvastatin were more than twice as likely to discontinue their treatment compared to those who remained on Lipitor therapy (20.5 percent versus 7.62 percent, p<0.001). The reasons for discontinuation were not available from the database, though disruption in treatment has been associated with poor adherence in previous studies of statins and other medications.

"The results of this analysis complement the large body of evidence from multiple clinical trials demonstrating the cardiovascular benefits of Lipitor," said Dr. Berelowitz. "Observational studies help the medical community better appreciate what is really happening in doctors' offices, and are commonly used by healthcare payors to set medical practice guidelines. This analysis highlights the need to carefully consider individual patient circumstances and cardiovascular risk because indiscriminate switching may adversely affect some patients."

Additional Study Information The primary endpoint was time to a first major cardiovascular event, defined as heart attack, stroke, or coronary revascularization (a type of heart surgery), or all-cause death. There was a statistically significant 30 percent increase in the relative risk of the primary endpoint (p=0.03).

  • The individual components making up the primary endpoint were analyzed as secondary endpoints. Compared with patients who did not switch therapy, switching was associated with the following:
    • Significant 43 percent increase in the relative risk of major cardiovascular events (p=0.008)
    • No difference in all-cause death (p=0.369)
  • The two treatment groups were matched based on the following: gender, history of heart attack, diabetes, time since last statin exposure and general practitioner treatment center.
  • The following statistical adjustments were made to address any residual imbalances: age, gender, prior statin exposure, time since last statin exposure, diabetes, history of heart attack, and baseline cholesterol levels.
  • Relative risk is the ratio of the risk of major cardiovascular events or death occurring in the group who switched from Lipitor to simvastatin versus the risk in the group who remained on Lipitor.

About Lipitor
Lipitor is the only statin with all the following criteria most important for many physicians, patients and payors: significant and proven cardiovascular event reductions, impressive average LDL lowering of 39 percent to 60 percent, and a proven safety profile across a broad range of patients.

Lipitor is the most prescribed cholesterol-lowering therapy in the world, with nearly 139 million patient-years of experience. It is supported by an extensive clinical trial program involving more than 400 ongoing and completed trials with more than 80,000 patients. There have been more than ten cardiovascular outcomes trials with more then 50,000 patients.

For further information, please visit:
http://www.pfizer.com

Most Popular Now

Pfizer receives positive FDA Advisory Committee vo…

Pfizer Inc. (NYSE: PFE) announced that the U.S. Food and Drug Administration's (FDA) Vaccines and Related Biological Products Advisory Committee (VRBPAC) voted that avail...

Engineered bacteria find tumors, then alert the au…

Combining discoveries in cancer immunology with sophisticated genetic engineering, Columbia University researchers have created a sort of "bacterial suicide squad" that ...

First nasal monoclonal antibody treatment for COVI…

A pilot trial by investigators from Brigham and Women's Hospital, a founding member of the Mass General Brigham healthcare system, tested the nasal administration of the ...

US FDA Advisory Committee votes to support effecti…

GSK plc (LSE/NYSE: GSK) announced that the US Food and Drug Administration (FDA) Vaccines and Related Biological Products Advisory Committee (VRBPAC) voted that the avail...

"Semantic similarity" leads to novel dru…

The words that researchers use to describe their results can be harnessed to discover potential new treatments for Parkinson's disease, according to a new study published...

Tumour cells' response to chemotherapy is driven b…

Cancer cells have an innate randomness in their ability to respond to chemotherapy, which is another tool in their arsenal of resisting treatment, new research led by the...

Pfizer invests $43 billion to battle cancer

Pfizer Inc. (NYSE: PFE) and Seagen Inc. (Nasdaq: SGEN) today announced that they have entered into a definitive merger agreement under which Pfizer will acquire Seagen, a...

Pfizer's ZAVZPRET™ (zavegepant) migraine nasal spr…

Pfizer Inc. (NYSE: PFE) today announced the U.S. Food and Drug Administration (FDA) has approved ZAVZPRET™ (zavegepant), the first and only calcitonin gene-related peptid...

Gene and cell therapies to combat pancreatic cance…

Pancreatic cancer is an incurable form of cancer, and gene therapies are currently in clinical testing to treat this deadly disease. A comprehensive review of the gene an...

Scientists reveal a potential new approach to trea…

Scientists at the National Institutes of Health and Massachusetts General Hospital in Boston have uncovered a potential new approach against liver cancer that could lead ...

Normalizing tumor blood vessels may improve immuno…

A type of immune therapy called chimeric antigen receptor (CAR)-T cell therapy has revolutionized the treatment of multiple types of blood cancers but has shown limited e...

Digital twin opens way to effective treatment of i…

Inflammatory diseases like rheumatoid arthritis have complex disease mechanisms that can differ from patient to patient with the same diagnosis. This means that currently...