Thoughts on clinical trials


I'm interested in knowing other people's thoughts and experiences with clinical trials. My dad was diagnosed last year with stage IV lung cancer. Ultimately it is incurable (terminal) but he has been on targeted therapy. This treatment has been working for 18 months, however we found out last week that is isn't working anymore. The plan is to try chemo but the doctors have been suggesting trying a clinical trial. I just wanted to know if it's worth it or if it's to risky? I'd love to hear your thoughts and opinions ☺️