Does anaphylactoid reaction to one immunotherapy agent exclude the possibility of using other immunotherapy agents?

Regarding PD1 inhbitors cross reactivity, I have never heard of patients having grade 3+ anaphylaxis with these agents. I have had several patients have infusion related reactions or delayed sensitivities from them. We, however, just re-challenge by slowing infusions rates, administering Benadryl (no steroids). Overall, these patients have done fine and have not required switches to other PD1 inhibitors. They are just not very immunogenic from a standpoint of hypersensitivity. Certainly, these a...