How does the cancer drug Keytruda work? And how is it different to chemo?

From today, the Australian government will expand Pharmaceutical Benefit Scheme (PBS) access to the drug Keytruda for three additional types of cancer. This is part of a broader shift away from cancer treatment with traditional chemotherapy drugs that can be less effective and have more intense side effects. So what is Keytruda? How does it work? And which cancers can it treat? The problems with standard chemo Most chemotherapy drugs developed in the 1950s to 1990s are small molecules that…