Efficacy and Toxicity of CD19 Chimeric Antigen Receptor T Cell Therapy for Lymphoma in Solid Organ Transplant Recipients: A Systematic Review and Meta-Analysis.

The safety and efficacy of chimeric antigen receptor (CAR) T cell therapy in solid organ transplant recipients is poorly understood, given the paucity of available data in this patient population. There is a theoretical risk of compromising transplanted organ function with CAR T cell therapy; conversely, organ transplantation-related immunosuppression can alter the function of CAR T cells. Given the prevalence of post-transplantation lymphoproliferative disease, which often can be difficult to treat with conventional chemoimmunotherapy, understanding the risks and benefits of delivering lymphoma-directed CAR T cell therapy in solid organ transplant recipients is of utmost importance. We sought to determine the efficacy of CAR T cell therapy in solid organ transplant recipients as well as the associated adverse effects, including cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and compromised solid organ transplant function. We conducted a systematic review and meta-analysis of adult recipients of solid organ transplant who received CAR T cell therapy for non-Hodgkin lymphoma. Primary outcomes included efficacy, defined as overall response (OR), complete response (CR), progression-free survival, and overall survival, as well as rates of CRS and ICANS. Secondary outcomes included rates of transplanted organ loss, compromised organ function, and alterations to immunosuppressant regimens. After a systematic literature review and 2-reviewer screening process, we identified 10 studies suitable for descriptive analysis and 4 studies suitable for meta-analysis. Among all patients, 69% (24 of 35) achieved a response to CAR T cell therapy, and 52% (18 of 35) achieved a CR. CRS of any grade occurred in 83% (29 of 35), and CRS grade ≥3 occurred in 9% (3 of 35). Sixty percent of the patients (21 of 35) developed ICANS, and 34% (12 of 35) developed ICANS grade ≥3. The incidence of any grade 5 toxicity among all patients was 11% (4 of 35). Fourteen percent of the patients (5 of 35) experienced loss of the transplanted organ. Immunosuppressant therapy was held in 22 patients but eventually restarted in 68% of them (15 of 22). Among the studies included in the meta-analysis, the pooled OR rate was 70% (95% confidence interval [CI], 29.2% to 100%; I2 = 71%) and the pooled CR rate was 46% (95% CI, 25.4% to 67.8%; I2 = 29%). The rates of any grade CRS and grade ≥3 CRS were 88% (95% CI, 69% to 99%; I2 = 0%) and 5% (95% CI, 0% to 21%; I2 = 0%), respectively. The rates of any grade ICANS and ICANS grade ≥3 were 54% (95% CI, 9% to 96%; I2 = 68%) and 40% (95% CI, 3% to 85%; I2 = 63%), respectively. The efficacy of CAR T cell therapy in solid organ transplant recipients is comparable to that in the general population as reported in prior investigational studies, with an acceptable toxicity profile in terms of CRS, ICANS, and transplanted organ compromise. Further studies are needed to determine long-term effects on organ function, sustained response rates, and best practices peri-CAR T infusion period in this patient population.