Arthur Allen in Slate:
Every year, in the name of medical progress, scientists breed and nurture hundreds of millions of mice, rats, and other subordinate mammals. Then they expose the critters to substances that could become the next Zocors, Prozacs, and Avastins. Since the alternative is to experiment on people, most everyone other than hardcore animal lovers accepts animal testing. Periodically, however, a spectacular failure raises new questions about the enterprise—not for ethical reasons, but scientific ones.
In March, London clinicians injected six volunteers with tiny doses of TGN1412, an experimental therapy for rheumatoid arthritis and multiple sclerosis that had previously been given, with no obvious ill effects, to mice, rats, rabbits, and monkeys. Within minutes, the human test subjects were writhing on the floor in agony. The compound was designed to dampen the immune response but it had supercharged theirs, unleashing a cascade of chemicals that sent all six to the hospital. Several of the men suffered permanent organ damage, and one man’s head swelled up so horribly that British tabloids refer to the case as the “elephant man trial.”
Animal rights activists in Britain pounced, declaring the uselessness of animal experimentation in the development of human drugs.