Among solid tumors, the curative potential of immunotherapies has been explored most in melanoma. One reason for this is that melanoma tumors often contain so-called immune infiltrates—patches of T cells, the killer cells of the immune system. It seems that these fighter cells arrive at the ‘battlefield’ to target tumor cells for killing, but instead become ‘frozen,’ unable to attack. How to activate the tumor-killing potential of T cells has been an area of intense and fruitful research, leading to the development of several immunotherapy drugs. Continue reading…
“Using vaccines to fight cancer is a field littered with failures but experts believe it is possible the approach could get a new lease of life if such shots are combined with a new class of drugs called checkpoint inhibitors.
“Unlike traditional preventative vaccines, therapeutic cancer vaccines are designed for people with established disease and are supposed to boost the patient’s immune system to keep tumors at bay.
“Unfortunately, the theory has not worked out in practice because, while the vaccines are successful at triggering a response from the ‘foot soldiers’ of the immune system, cancer cells still manage to escape detection.
“The result has been a series of failures with high-profile experimental cancer vaccines such as Merck KGaA’s Stimuvax and GlaxoSmithKline’s MAGE-A3.
“GSK threw in the towel on its vaccine in April, dashing hopes for a project that was once seen as a potential multibillion-dollar sales opportunity in lung cancer and melanoma.”
“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.”