P1158: real-world patient characteristics, treatment patterns, and treatment outcomes of patients with diffuse large b-cell lymphoma (dlbcl) by line of therapy (lot)

Topic: 19. Aggressive Non-Hodgkin lymphoma - Clinical Background: DLBCL is the most commonly diagnosed subtype of Non-Hodgkin lymphoma (NHL), and first line (1L) standard of care (SOC) remains chemoimmunotherapy with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone). Although initial treatment can be effective, with nearly 60% of patients achieving remission with 1L treatment, up to 50% of patients will subsequently develop refractory or relapsed (R/R) disease. Although the treatment landscape in the R/R setting has evolved with the recent new drug approvals, the SOC is less well-defined, and contemporary data on patient characteristics, treatment patterns, and treatment outcomes remain limited. Aims: To examine the contemporary patient characteristics, treatment patterns, and treatment outcomes of patients with DLBCL by LOT. Methods: Adult patients (pts) age ≥ 18 years were identified in the COTA real-world (rw) database comprised of data abstracted from the electronic health records of partnered healthcare provider sites in the United States. Pts were required to have initiated 1L following an initial diagnosis (dx) of Ann Arbor Stage I-IV DLBCL on or after January 1, 2016 until March 31, 2021. Pts were excluded if they had a non-qualifying histology, a prior dx of a hematologic malignancy, a dx of primary central nervous system lymphoma, or any clinical trial participation. The index date for the study was the date of initiation of the relevant LOT. Baseline characteristics, treatment patterns, and rw treatment outcomes including time to next treatment (TTNT) and overall survival (OS), were assessed for the study population and by LOT. Results: A total of 1,347 eligible pts were identified for the study. Analysis by LOT showed that 340 pts (25.2%) of those who received 1L proceeded to receive 2L, of which 141 (41.5%) proceeded to receive 3L, and 51 (36.2%) proceeded to receive 4L. Median age at dx was 67 years (IQR: 57-75). The majority of the pts were White (79.4%), male (54.9%), and treated in the community practice setting (81.3%). Median follow up time from dx for the study population was 28.0 months (IQR: 14.6, 43.0), and the median time from dx to 1L treatment initiation was 0.8 months (IQR: 0.5, 1.3). There were 520 (38.6%) pts with Stage IV disease, and 192 (14.3%) with Eastern Cooperative Oncology Group (ECOG) performance score ≥2. Germinal center B-cell-like was the most common subtype (39.3%). A high proportion of pts tested positive for the following molecular markers: BCL2 (70.3%), BCL6 (78.8%), C-MYC (40.4%), CD10 (45.4%), and CD20 (91.2%). R-CHOP was the most commonly used regimen in 1L (63.6%). In 2L, 59 pts (17.4%) received autologous stem cell transplant. Five (1.5%) and 14 (9.9%) pts received CAR-T therapy in 2L and 3L, respectively. R/R disease was more common in later LOTs (48.8% in 2L, 40.5% in 3L, and 54.9% in 4L). Median OS and TTNT were not reached (NR) for the 1L population, and median OS and TTNT for the 2L population were 29.2 months (95% CI: 17.3, NR) and 6.3 months (95% CI: 5.0, 8.5), respectively. One-, 3-, and 5-year survival rates for the study population were 88.5%, 78.4%, and 73.5%, respectively. Pts who received later LOTs had considerably lower 1- and 3-year OS (2L OS rates at 1-year: 62.4% & 3-year: 46.4%). (Figure 1) Summary/Conclusion: In this rw analysis, large proportions of pts with DLBCL had R/R disease and received subsequent LOTs. While 3-year survival rate for DLBCL pts receiving 1L was high, pts experiencing R/R disease who received 2L+ had remarkably lower 3-year OS rates. There is a high unmet need for new and effective treatment options for pts with R/R DLBCL.Keywords: DLBCL, Outcome, Survival, Treatment