Guided by target selection, inotuzumab ozogamicin successfully salvaged a patient with refractory follicular lymphoma after anti-CD19 and anti-CD22 CAR T-cell therapy: a case report and literature review.

Although Chimeric antigen receptor (CAR) T-cell therapy has achieved a high response rate in recurrent/refractory (R/R) B-cell non-Hodgkin lymphoma (NHL), the prognosis of the patients who do not respond to this therapy or have a disease progression again is poor. A 69-year-old male patient was diagnosed with refractory follicular lymphoma (FL) had 43.6% abnormal B lymphocytes expressing CD20-, CD19+, CD22 + in his pleural effusion. He received anti-CD19 CAR T-cell combined with anti-CD22 CAR T-cell therapy in our hospital, but he achieved stable disease (SD) only two months after CAR-T cell infusion. When his disease progressed again, there were 40.2% abnormal B lymphocytes expressing CD19-, CD20-, CD22 + in pleural effusion. Because CD22 was the only antigen expressed on his lymphoma cells at this time, reduced-dose of Inotuzumab Ozogamicin (InO) was chosen as a salvage therapy (InO 1 mg on day 1, 8, 15). The main adverse events (AE) of this salvage therapy were haematological toxicity. He was evaluated as complete remission (CR) two months after InO salvage therapy. His haematological toxicity was gradually recovered in the following six months. To date, this refractory FL patient has achieved continuous CR and maintained more than three years of event-free survival from the salvage therapy of InO. InO might be an effective and feasible salvage therapy for refractory FL patients who have failed to CAR-T cell therapy. Moreover, immunotherapy of R/R B-cell NHL could be achieved through target selection of lymphoma cells.