Recovery of humoral immunity in patients with durable complete responses following chimeric antigen receptor modified t cells directed against CD19 (CTL019).

Abstract

7564Background: Autologous T cells genetically modified to express a chimeric antigen receptor with an external anti-CD19 antibody domain, and CD3ζ and 4-1BB signaling domains (CTL019) can achieve remissions in patients (pts) with relapsed/refractory (r/r) CD19+ non-Hodgkin lymphomas (NHL). We studied the effect of this therapy on humoral immunity. Methods: Serial immunoglobulin (Ig) levels were measured in pts with complete response (CR) to CTL019 on a phase II trial. Pts had r/r CD19+ follicular lymphoma (FL), diffuse large B cell lymphoma (DLBCL), or mantle cell lymphoma (MCL). After collection of lymphocytes, pts received lymphodepleting chemotherapy followed 1 - 4 days later by 1 - 5 x 108CTL019 cells intravenously. Response was assessed every 3 months (mo) for 24 mo. Enrollment is reported from Feb 2014 – Nov 2015, survival analyses through Jan 2016. Results: 43 pts enrolled: median age 56 years (range 25-77); female: male ratio 17:26; median prior therapies 4 (range 1-19); prior ASCT 14 (33%). 30 p...