Response rates of extra‐nodal diffuse large B cell lymphoma to anti‐CD19‐CAR T cells: A real word retrospective multicenter study

Chimeric antigen receptor T-cells (CAR-T) are widely used for the treatment of relapsed/refractory diffuse large B cell lymphoma (DLBCL). The data for CAR-T cell therapy in patients with extra-nodal (EN) lymphoma is restricted. We included 126 consecutive patients with DLBCL treated with commercially available CAR-T cells (tisagenlecleucel, n = 100, 79.4% and axicabtagene ciloleucel, n = 26, 20.6%). At lymphodepletion, 72 of 126 (57%) patients had EN disease, 42 of 126 (33%) patients had nodal disease (ND)-only and 12 of 126 (10%) showed no disease assessed by PET-CT. There were no significant differences in CAR-T related toxicities and in the median Progression free survival (PFS) between EN patients and ND (10.76 [95% CI: 7.8-13.6] vs. 14.1 [95% CI: 10-18.1] months, p = .126). Similarly, median overall survival (OS) was not significantly different (15.36 [95% CI 12.5-18.2] vs. 18.4 [95% CI 14.8-22.1] months, p = .100). Subgroup analysis according to the number of EN involved sites showed that median PFS and OS were significantly higher in patients with <3 EN sites (12.3 months [95% CI 9-15.5] vs. 4.28 months [95% CI 0.6-7.9], p = .010) compared to patients with >2 EN sites, respectively (16.5 months [95% CI 13.4-19.6] vs. 8.7 months [95% CI 4.6-12.8], p = .05). In multivariate cox regression analysis, increased number sites of EN disease and high lactate dehydrogenase (LDH) at lymphodepletion negatively impacted PFS (p = .021 and <.001, respectively), while sex, type of product administered, age and performance status did not predict PFS and OS. Of note, all the patients with involvement of gastrointestinal tract (n = 9), urinary tract (n = 9), or pharynx (n = 3) at lymphodepletion, progressed or had an early relapse. In conclusions, patients with >2 EN sites at lymphodepletion have significantly worse clinical outcomes compared to patients with <3 EN sites. Patients with specific sites of EN disease may demonstrate grim prognosis.