New therapies raise hope for a breakthrough in tackling cancer

In the summer of 2012, a year after his wife had died of lung cancer, Michael Harris scraped open an old mole on his back and it would not stop bleeding. The doctors said he had stage 4 melanoma, with a virtually inoperable tumor, and that patients in his condition typically lived about eight months. By last June, the cancer had spread to his liver and lungs.

At that point Harris joined a clinical trial at Georgetown University, one of scores that have sprung up around the country to test a new class of cancer drugs called immune-checkpoint inhibitors. Two weeks after his first infusion, Harris’s primary tumor was fading, along with the black cancerous beads around it. A month later, his liver and lungs were clean.