- Case Report
Fatal Early Toxicity After Allogeneic Stem Cell Transplantation in Heavily Pretreated Follicular Lymphoma: Clinical Decision-Making Between Bispecific Antibodies and CAR T-Cell Therapy
- Martina Canichella,
- Raffaella Cerretti and
- Monika Malgorzata Trawinska
- + 7 authors
For patients with relapsed/refractory (R/R) follicular lymphoma (FL) after ≥2 prior lines of therapy, T-cell-redirecting therapies—including the bispecific CD3xCD20 antibody (BsAbs) mosunetuzumab (mosu) and chimeric antigen receptor T-cell (CAR-T) therapies such as axicabtagene ciloleucel (axi-cel), lisocabtagen maraleucel (liso-cel), and tisagenlecleucel (tisa-cel)—are approved by the FDA and EMA. Treatment selection should consider patient-related factors, prior therapeutic exposure, and toxicity profiles. We describe the 20-year history of a patient with R/R FL. At the fourth relapse, both BsAbs and CAR-T cells were available; however, due to the cumulative toxic burden and the high risk of cytopenias, mosu was selected as the preferred option. During mosu, the patient developed pure red cell aplasia unrelated to infections. Despite achieving a partial response after eight cycles of mosu, this complication led to the decision to proceed with allogeneic stem cell transplantation (allo-HSCT). The course was ultimately complicated by severe early toxicity with massive hemoptysis, acute respiratory failure, and hemorrhagic alveolitis, resulting in a fatal outcome. This case illustrates the delicate balance required in selecting between BsAbs and CAR-T therapy in R/R FL. Contributing factors to the patient’s fragility included profound immune status, transfusion-dependent red cell aplasia, prior cumulative chemotherapy, and pulmonary toxicity associated with conditioning regimens. The case underscores the importance of individualized treatment strategies and suggests that earlier integration of novel T-cell-redirecting therapies may mitigate cumulative toxicity and infection risk. Individualized therapeutic planning is critical in heavily pretreated R/R FL. In select cases, bridging strategies using BsAbs can provide disease control and facilitate transplantation. Still, careful assessment of patient fitness, marrow reserve, and cumulative toxicity is essential to minimize the risk of fatal complications.
10 December 2025




