Copanlisib was subsequently approved for use in the third-line setting and remains a third-line therapy for relapsed or refractory follicular lymphoma.22 Moxetumomab pasudotox-tdfk, a recombinant CD22-directed cytotoxin, was studied in a single-arm phase 3 trial23 in patients with relapsed or refractory hairy cell leukemia with at least 2 or more prior systemic therapies. Here, CD22 is linked to hairy cell leukemia.