For the first time, a cancer drug has been approved based on a genetic defect instead of a specific type of cancer. The drug, pembrolizumab (Keytruda®), works by preventing cancer cells from stopping the immune system. The end result is immune activity against cancer. Up until now cancer drugs were approved for individual cancer types. This new approval allows the treatment of cancers with a shared genetic defect. The defect, in a process called 'mismatch repair', makes the cells more likely to develop specific kinds of DNA mutations. This will make the drug available to many patients who would not otherwise have effective treatment options. A big step!
By Yikrazuul - Own work; http://mt.seas.upenn.edu/Archive/Graphics/A/gallery.html, Public Domain, https://commons.wikimedia.org/w/index.php?curid=9900400