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Back in the ’90s, immunologist James Allison wasn’t trying to develop a cancer drug. “I was doing just really fundamental research trying to understand T-cell regulation,” he says. But in the course of that work, performed at the University of California, Berkeley, Allison discovered that a protein receptor called CTLA-4 negatively regulated T-cell responses to antigens, and that inhibiting that receptor with an antibody enhanced T-cell activity.
The clinical applications were obvious. “I had the idea that you might be able to exploit that to get immunological responses, T-cell responses, to tumor cells,” says Allison, now chair of immunology and director of immunotherapy at the University of Texas’s MD Anderson Cancer Center. In a 1996 Science paper, he and his colleagues reported that, in mice, ...
