Historically, clinicians have fought cancer with tools such as radiation, surgery and chemotherapy, which kill cancerous cells, but also damage healthy cells or nearby tissues. Immuno-oncology presents a whole new treatment paradigm; it tunes the immune system to specifically fight cancer cells with better outcome of survival rates. Richard Harrison, Chief Scientific Officer at Clarivate Analytics, talks about the advent of immuno-oncology therapies, the challenges and competitive environment, and the promise for the future.