Just is quite right, chris. The people running the tests on the new medicine are not trying to be mean, that is the nature of clinical trials. The doctor offering meds to keep him comfortable (palliative care, that's called)is attempting to be kind to your dad, even if it doesn't seem that way. Let the doctors make your dad comfortable.
You might want to be contacting any hospice that is nearby. They are not just there for your dad, but for you and your family.