Treatment for stage 4 lung cancer

My dad is due to start his treatment next week. He is having chemo & immunotherapy. The chemo is Carboplatin and Paclitexel, and the immuno is Pembrolizimab. He is having 4 cycles and then review for a response with a view to ongoing immuno if he does have a good response.

Has anyone had this treatment previously and if so, how were your results? And how well did you tolerate it?

I obviously know everyone is different but just asking for some feedback.

At the moment he is just very anxious it won’t work. We are trying to keep him positive and I know it’s easy to tell him to be positive but also understand why he is having doubts.