Loncastuximab in High-Risk and Heavily-Pretreated Relapsed/Refractory Diffuse Large B-Cell Lymphoma: A Real World Analysis from 21 US Centers

Background: In the LOTIS-2 study, patients (pts) with relapsed/refractory (R/R) DLBCL treated with loncastuximab-tesirine (lonca), a CD19 directed antibody-drug conjugate, demonstrated an overall response rate (ORR) and complete response rate (CRR) of 48.3 % and 24.1%. However, there is a paucity of data evaluating outcomes with lonca in the real-world setting (RWS). Hence, we performed a multicenter retrospective study to describe pt characteristics and clinical outcomes in R/R DLBCL pts receiving lonca in this setting. Methods: This retrospective study included pts with R/R DLBCL treated with commercial lonca at 21 academic centers in USA. Clinicopathologic data, treatment outcomes and adverse event (AE) data were collected. Progression-free survival (PFS) and overall survival (OS) were estimated using Kaplan-Meier method and characteristics associated with survival and CR calculated using Cox proportional hazards model and logistic regression. Response was assessed per institutional standards. Results: 187 pts were analyzed with a median follow-up of 12.5 months (mo). Median age was 68 years (range 22-95), 64% male, and 85% white ( Table 1). Most common histology was DLBCL (55% de novo, 22% transformed from low-grade) and 19% were double hit (DH). Thirty-two percent (n=59) had primary refractory disease, 17% (n=31) prior autologous transplant, and 60% (n=112) prior CAR T-cell therapy (CART). Median number of treatment lines before lonca was 4 (1-11) with 81% (n=151) receiving lonca in 4 th line (4L) or later and 8 pts treated off-label in 2 nd line. More pts receiving lonca in ≥4L had prior CART (72% vs 8%, p 4L were 15%, 13%, and 15% with ORR of 44%, 26%, and 33%, respectively. Figure 1 shows PFS stratified by response with median PFS not reached in those achieving CR. Patients with a CR to last therapy prior to lonca had superior median PFS (8.8 vs 2.0 mo, p