April 17, 2015
The use of mice in biomedical research is coming under increasing fire for failing to model human disease. In March, The Guardian published an article (“Mice losing their allure as experimental subjects to study human disease”), which reinforced and strengthened the arguments against using mice.
Dr. Clifton Barry, Chief of Tuberculosis Research at the National Institutes of Health, told The Guardian about three recent drug regimens – at a cost of $200 million – that cured mice of TB but were a complete failure when tested on humans.
Dr. Barry wasn’t completely surprised. Through his years of research, he’d learned that TB in mice differs greatly from human TB. Mice cannot cough and they are not contagious when infected with TB. This is in stark contrast to roughly 2 billion people around the world who may be healthy carriers of TB.
Dr. Barry continued to investigate these differences between mice and humans in search of a cure, until three years ago when he was asked to test an antibiotic, Linezolid, that had been successful at treating respiratory conditions in people. Dr. Barry tested it in his mouse lab, with no success. But when he tested it on humans, “I was amazed. The previous treatments [of Linezolid] had been discovered without animal experimentation. …I couldn’t go on looking after mice any longer. It’s a dead end.”
But not totally. Because Dr. Barry, who has seen firsthand the total failure of mice research to shed light on cures for human TB, still believes that “They’re fine for ordinary work like toxicology trials. Perfect for checking that no unwanted side-effects crop up when we try a new molecule.”
Has Dr. Barry, as head of a lab at NIH, not heard that 95% of drugs thought to be promising after experiments on mice fail in human clinical trials?
Has he also not heard that the failure of animal models (including mice) in toxicology has led the Environmental Protection Agency and three other U.S. regulatory agencies to announce a new program to use non-animal methods to predict the toxicology of chemicals for human exposure?
Sadly, Dr. Barry is not alone. Far too many scientists are pigeon-holed in their specialties and don’t take a broad view of the situation. Like a cross between the “Blind Men and the Elephant” meets “The Emperor’s New Clothes,” researchers go on believing that though mice may not be useful for them, they are useful for somebody.
But are they?
In 2013, Warren Shaw, MD an infectious disease specialist at Massachusetts General Hospital, and 39 collaborators published a watershed study demonstrating that despite decades of research on mice to produce treatments for inflammatory illnesses – encompassing burns, sepsis and wounds – the outcomes had been a failure. Of 150 clinical therapeutic agents shown to be effective in mice, every single one failed on humans.
In fact, so far reaching are the failures of mice to predict success in human medicine that the former head of the NIH, Dr. Elias Zerhouni, said in his 2013 address to a room full of scientists at the NIH:
“We have moved away from studying human disease in humans. …With the ability to knock in or knock out any gene in a mouse, researchers have over-relied on animal data. …The problem is that it hasn’t worked, and it’s time we stopped dancing around the problem… We need to refocus and adapt new methodologies for use in humans to understand disease biology in humans.”
A shift has begun, but the industries that make billions of dollars from mouse research are a mighty force. This is why CAARE works hard to educate the public. Knowledge is empowerment, and only an enlightened society can advocate for meaningful change.
Citizens for Alternatives to Animal Research (CAARE), is a 501(c)(3) non-profit organization, established to highlight and promote research without animals.