REAL-WORLD USE OF TAFASITAMAB FOR RELAPSED OR REFRACTORY DIFFUSE LARGE B-CELL LYMPHOMA IN THE UNITED STATES BY AGE GROUP (> 70 YEARS AND 70 YEARS)

Abstract

Objectives: Diffuse large B-cell lymphoma (DLBCL) is an aggressive form of lymphoma that occurs more frequently in older adults. Tafasitamab, a CD19-targeting immunotherapy, combined with lenalidomide, was approved by the US Food and Drug Administration for treatment of relapsed or refractory (R/R) DLBCL in adults ineligible for autologous stem cell transplantation (ASCT). In a recent US real-world study of tafasitamab treatment for R/R DLBCL, more than half of the patients were older than 70 years. Here, we describe patient characteristics, treatment patterns, and outcomes observed in this study by patient age at tafasitamab initiation (> 70 years, ≤ 70 years). Material and methods: This was a retrospective chart review wherein physicians from Cardinal Health's Oncology Provider Extended Network abstracted data from patients’ medical records into electronic case report forms. Eligible patients (aged ≥ 18 years) initiated tafasitamab for R/R DLBCL on or after October 21, 2020, and had ≥ 4 months of follow-up; however, patients who died during follow-up were also eligible. Results were summarized by patient age at tafasitamab initiation (> 70 years, ≤ 70 years) using descriptive statistics. Results: Among the 181 patients included in this analysis, 102 (56%) were > 70 years and 79 (44%) were ≤ 70 years of age at time of tafasitamab initiation. Median age at tafasitamab initiation was 75.2 and 64.2 years for the > 70 and ≤ 70 years subgroups, respectively. Overall, median (Q1-Q3) follow-up time was 6.5 (5.0-8.6) months. At time of data abstraction, 76 patients (75%) in the > 70 years and 68 (86%) in the ≤ 70 years subgroups were still alive, of whom 67 (88%) and 54 (79%) were still receiving tafasitamab, respectively. Approximately half of patients (49%) in the ≤ 70 years group and 23% in the > 70 years group had no comorbidities associated with the National Cancer Institute Comorbidity Index. At the time of tafasitamab initiation, 54% and 39% of patients in the > 70 and ≤ 70 years subgroups had an ECOG PS ≥ 2; most patients (86%, > 70 years; 74%, ≤ 70 years) had a revised International Prognostic Index score of 3-5. In both subgroups, the majority of patients (79%, > 70 years; 62%, ≤ 70 years) received tafasitamab as second-line therapy. Nearly a quarter of patients (23%) in the ≤ 70 years group and 3% in the > 70 years group had undergone ASCT prior to tafasitamab treatment. Real-world overall response rates (95% CI) were 70.6% (61.7-79.4%) and 69.6% (59.5-79.8%) in the > 70 and ≤ 70 years subgroups, respectively. Discussion: Results from this analysis indicate favorable response rates with tafasitamab treatment among patients with R/R DLBCL in both the > 70 and ≤ 70 years subgroups. At tafasitamab initiation, the majority of patients in both subgroups had revised International Prognostic Index scores indicative of a poor prognosis. Despite meaningful comorbidity burden and limitations in performance status, at time of data abstraction, 88% of patients in the > 70 years group were still receiving tafasitamab. However, follow-up was limited in duration. Conclusion: These real-world findings support the clinical benefit of tafasitamab among older (> 70 years) and younger (≤ 70 years) patients with R/R DLBCL. Longer follow-up is warranted to better assess long-term outcomes with tafasitamab by age. Funding: Incyte Corporation.