Pharmaceutical firm Pfizer Inc. recently said that three large long-term Celecoxib studies involving more than 6,000 patients have not shown any significant safety issues and are expected to continue to completion.

The ongoing studies, which are assessing Celecoxib as a potential preventive treatment in both Alzheimer’s disease and colorectal cancer, have been under way at multiple medical centers worldwide for several years.

The studies are being conducted by the National Cancer Institute, the National Institutes of Health and Pfizer.

The evidence distinguishing the cardiovascular safety of Celecoxib has accumulated over years in multiple completed studies, none of which has shown any increased cardiovascular risk of Celecoxib, one the world’s most prescribed arthritis and pain relief brand.

“Each COX-2 inhibitor has a distinct chemical structure and we would not expect them to have the same side effect profile,” said Dr. Joe Feczko, Pfizer’s president of worldwide development. “The data we’ve accumulated over time demonstrate that Celecoxib does not increase the risk of serious cardiovascular events in patients with arthritis and pain, even at higher-than-recommended doses.”

Two of the large placebo-controlled studies under way - one sponsored by the National Cancer Institute and the other by Pfizer - are designed to determine whether Celecoxib reduces the recurrence of pre-cancerous polyps in patients who have previously had polyps removed. Both studies, which are following patients over a five-year period, have enrolled roughly 4,000 patients, some who have participated for more than four years.

A third placebo-controlled study examining Celecoxib‘s potential to prevent or show the progression of Alzheimer’s disease, is sponsored by the National Institute of Health and has enrolled about 2,400 patients to date over the past three years.

“It is important to note that Alzheimer’s patients are typically elderly and therefore at higher risk for cardiovascular events,” said Dr. John Breitner of the Seattle VA and the University of Washington and Alzheimer’s Disease Anti-Inflammatory Prevention Trial (ADAPT) Study Chair.

“To date we have seen no evidence that there is any increased cardiovascular safety risk among study patients.”

All three studies are monitored by independent safety experts who meet regularly to assess adverse events.

So far, no significant safety concerns have been raised that could potentially put patients at risk.

Over 27 million patients in the United States have been prescribed with Celecoxib, which was approved by the U.S. Food and Drug Administration in 1998.

Since then, data show that the rate of hospitalizations from adverse gastrointestinal events associated with long-term NSAID use has declined markedly.

In the Philippines, Celecoxib was approved by the Bureau of Food and Drugs in 1999 and there have been over four million prescriptions since its launch.