Pfizer is fighting back against a report that it hid the potential of a blockbuster drug to prevent Alzheimer’s disease in order to avoid shelling out for a “costly clinical trial.”

Researchers at Pfizer in 2015 found that Enbrel, an anti-inflammatory drug used to treat rheumatoid arthritis, seemed to reduce the risk of Alzheimer’s disease by 64 percent, the Washington Post reported Tuesday.

But a clinical trial on 3,000 to 4,000 patients to test the hypothesis would have cost about $80 million, according to research prepared by Pfizer’s inflammation and immunology department and seen by the Washington Post.

The Washington Post noted that Enbrel was near the end of its 20-year patent life and financial incentives for further research into the drug were “diminishing.”

But Pfizer contends that its decision not to pursue a study of Enbrel’s other possible uses was motivated by science and not money.

“Our decision not to pursue a broader clinical trial … [was] based first and foremost on scientific rationale and not on the basis of financial incentives as the story seems to imply,” Pfizer said in a statement after the Washington Post story ran.

The data was found from a review of 127,000 insurance claims completed by Pfizer employees. The group split the claims equally between people who had Alzheimer’s and those who did not. In the group of people who did not have Alzheimer’s, 302 were treated with Enbrel. Only 110 in the group with Alzheimer’s had used Enbrel, it was reported.

Members of the medical community the Washington Post spoke with argued that Pfizer should have done more to publicize the potential uses of Enbrel to spur other research even if the drugmaker didn’t plan to do its own study.

“Having acquired the knowledge, refusing to disclose it to those who might act upon it hides a potential benefit, and thereby wrongs and probably harms those at risk of developing Alzheimer’s by impeding research,’’ said Bobbie Farsides, professor of clinical and biomedical ethics at Brighton and Sussex Medical School in London.

But not all of the people the Washington Post spoke with agreed.

“I do think you have to draw some limits, and say that not every piece of information they have in their files has to be disclosed with others,’’ said Marc Rodwin, a professor at Suffolk University Law School in Boston.

A source close to Pfizer told the New York Post that the drug giant publishes findings that meet the “gold standard” of medical research versus “hunches.”

While researchers have been studying the role of brain inflammation in Alzheimer’s, Pfizer during a three-year internal review determined that a clinical trial was not likely to be successful because the drug doesn’t reach brain tissue.

A study of 41 patients published by the American Academy of Neurology in May 2015 about potential uses for Enbrel proved to be inconclusive.

“While there were some interesting trends that favored [Enbrel], there were no statistically significant changes in cognition, behavior, or global function,” according to an abstract of the researcher’s findings.