Survival outcomes of patients newly diagnosed with diffuse large B-cell lymphoma: real-world evidence from a German claims database

Identification of Adjustment Variables in Indirect Comparisons: A Rapid Review of CAR-T Therapies for Diffuse Large B-Cell Lymphoma

Background: Chimeric antigen receptor T-cell (CAR-T) therapies have been approved by the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for the treatment of diffuse large B-cell lymphoma (DLBCL), primarily based on single-arm trials or indirect comparisons with stem cell transplantation. However, no direct head-to-head comparisons of CAR-T therapies have been conducted, largely due to their high cost. To assess their true value, indirect treatment comparisons (ITCs) are essential. These comparisons, however, are prone to confounding biases, which necessitate careful adjustments through the identification and measurement of relevant variables. Materials and Methods: This study aims to identify the variables used for adjustment in ITCs of CAR-T therapies for DLBCL and examine the methodologies employed to select them. A rapid literature review was conducted in PubMed in September 2023, focusing on ITCs involving CAR-T therapies for DLBCL. The search was based on keywords categorized into three groups: techniques (ITCs and related terms), drugs (CAR-T therapies), and indication (DLBCL). Results: The rapid literature review identified 21 articles, of which 11 were selected for analysis. Exclusions were made for articles that did not identify confounders, were letters to editors, or addressed conditions other than DLBCL. Among the 11 selected publications, 10 did not clearly specify the methodology used to identify adjustment variables. A total of 25 potential confounders were identified across the studies, with substantial variability in the set of variables used, reflecting a lack of standardization in confounder selection. Commonly identified confounders included the number of prior treatment lines and Eastern Cooperative Oncology Group Performance Status (ECOG PS), although their inclusion as adjustment variables in ITCs was inconsistent, often due to missing data. Conclusions: While the identified confounders are clinically relevant, the methodologies for selecting them remain unclear, resulting in significant variability across studies. Additionally, key variables commonly considered in health technology assessments (HTAs), such as age, sex, and disease severity, were inconsistently incorporated into ITCs. To improve the reliability and consistency of ITC outcomes, there is a pressing need for standardized methodologies for identifying and adjusting for confounders.

Low Rate of Central Nervous System Relapse of Diffuse Large B-Cell Lymphoma Despite Limited Use of Intrathecal Prophylaxis

Background

The incidence of central nervous system (CNS) relapse in diffuse large B-cell lymphoma (DLBCL) varies, and the optimum strategy of CNS prophylaxis remains to be defined. We aimed to evaluate the incidence of CNS relapse in DLBCL patients and the role of CNS prophylaxis.

Methods

Data on patients diagnosed with DLBCL at our institution from January 2011 to June 2019 were retrospectively collected from the charts and computerized hospital information system for patient demographics, lymphoma stage at diagnosis, CNS international prognostic index (IPI) scores, extra-nodal sites, chemotherapy type, CNS prophylaxis, and CNS relapse. CNS prophylaxis comprised intrathecal (IT) chemotherapy and was administered based on the presence of high-risk features. Patients with primary CNS lymphoma and CNS involvement at diagnosis were excluded.

Results

Of 101 patients, 58 (57.5%) were males with a median age of 56 (range: 16 - 87) years. Ann Arbor stages of I - IV were confirmed in nine, 21, 17, and 50 patients, respectively. The lung was the most common extranodal site involved (27, 26.7%). Twenty-five (24.75%) patients had a high-risk CNS-IPI score. Ninety-three percent of patients received R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) chemotherapy. Sixteen patients received CNS prophylaxis as IT methotrexate (± cytarabine and hydrocortisone). Despite high-risk CNS-IPI scores, nine (36%) patients did not receive CNS prophylaxis. After a median follow-up of 36 (range: 4 - 114) months, two patients with high-risk CNS-IPI score developed CNS relapse and died shortly.

Conclusions

CNS relapse of DLBCL was uncommon in this patient population. Low incidence of CNS relapse despite limited use of IT prophylaxis may suggest adequacy of IT prophylaxis in these patients.

Survival outcomes of patients with diffuse large B-cell lymphoma undergoing autologous stem cell transplantation in Germany: real-world evidence from an administrative database between 2010 and 2019

Background

Limited real-world evidence is available for patients with diffuse large B-cell lymphoma (DLBCL) who received an autologous stem cell transplantation (ASCT) in Germany.

Objectives

This study aims to describe the real-world survival outcomes of patients with DLBCL who received ASCT in Germany after diagnosis.

Design

This study is a retrospective database analysis covering the period between 2010 and 2019.

Methods

Unadjusted overall survival (OS) was plotted using the Kaplan-Meier estimator for the overall population and stratified by relapse status. A Cox regression was run to identify factors that influence OS.

Results

A total of 112 patients received an ASCT, with the average time from first-line treatment to ASCT being 11.7 months. The median OS estimated by Kaplan-Meier was 83.4 months for the entire cohort. The only variable that significantly reduced the OS was the presence of subsequent treatment after ASCT in a time-dependent model.

Conclusion

OS after ASCT for DLBCL patients in Germany is higher than previously reported and may still be considered a valid option for carefully selected patients with relapsed/refractory DLBCL.

Comparative effectiveness of 6x R-CHOP21 versus 6x R-CHOP21 + 2 R for patients with advanced-stage diffuse large B-cell lymphoma

First-line treatment for advanced-stage diffuse large B-cell lymphoma (DLBCL) typically involves 6x R-CHOP21 or 6x R-CHOP21 with two additional rituximab administrations (6x R-CHOP21 + 2 R). In contemporary practice, this treatment choice might be guided by interim PET scan results. This nationwide, population-based study investigates the comparative effectiveness of these treatment regimens in an era where interim PET-guided treatment decisions were not standard practice. Utilizing the Netherlands Cancer Registry, we identified 1577 adult patients diagnosed with advanced-stage DLBCL between 2014-2018 who completed either 6x R-CHOP21 (43%) or 6x R-CHOP21 + 2 R (57%). We used propensity scores to assess differences in event-free survival (EFS) and overall survival (OS). At five years, EFS (hazard ratio of 6x R-CHOP21 + 2 R versus 6x R-CHOP21 [HR] = 0.89; 95% confidence interval [CI], 0.72-1.09) and OS (HR = 0.93; 95% CI, 0.73-1.18) were not significantly different between both regimens. In exploratory risk-stratified analysis according to the International Prognostic Index (IPI), high-IPI patients (i.e., scores of 4-5) benefit most from 6x R-CHOP21 + 2 R (5-year absolute risk difference of EFS = 16.8%; 95% CI, -0.4%-34.1% and OS = 12.1%; 95% CI, -5.4-29.6%). Collectively, this analysis reveals no significant differences on average in EFS and OS between the two treatments. However, the potential benefits for high-risk patients treated with 6x R-CHOP21 + 2 R underscore the need for future research.

Epidemiology and Real-World Treatment of Incident Diffuse Large B-cell Lymphoma (DLBCL): A German Claims Data Analysis

INTRODUCTION

The objective of this study was to investigate the prevalence, incidence, and treatment patterns (treatment regimens, switches, duration) for diffuse large B-cell lymphoma (DLBCL) in a real-world setting.

METHODS

This was a retrospective German claims data analysis of patients with DLBCL diagnosed between January 1, 2012, and December 31, 2020. The prevalence and cumulative incidence of DLBCL were found for 2019/2020. Line of treatment  (LOT) and treatment setting from first DLBCL diagnosis to end of follow-up were described. Kaplan-Meier overall survival (OS) estimates since DLBCL diagnosis and start of treatment lines were calculated.

RESULTS

Overall, 2633 incident DLBCL cases were identified (median age 75 years, 51% male). Of these, 2119 patients received at least one DLBCL-related treatment (LOT1), and 1567 patients died during follow-up. In 2019/2020, the prevalence and cumulative incidence of DLBCL was 34.8/36.7 per 100,000 patients and 14.0/12.7 per 100,000 patients, respectively. For LOT1, 1922 patients were given a chemotherapy-based regimen (1530 with CD20 antibodies). A total of 403 patients were administered a second line (LOT2), of which 183 patients received a CD20 antibody-containing chemotherapy regimen and 100 patients received stem cell transplantation or chimeric antigen receptor (CAR)-T therapy. Of the 136 LOT3+ treatments, 74 were chemotherapy regimens (54 with CD20 antibodies) and 18 were kinase inhibitors. The median time between treatment lines was less than 6 months. Among patients with at least LOT2, approximately 50% received more than one LOT during the first year after diagnosis. Approximately 25% of treated patients died within 6 months of treatment initiation. Of the 2633 included patients, the median OS from diagnosis was 31.0 months (treated patients: 46.8 months, untreated patients: 3.0 months).

CONCLUSIONS

Despite advances in the field, high unmet medical need in DLBCL remains. The treatment landscape is very heterogeneous, particularly in second- or later-line treatments, with few patients receiving potentially curative treatment beyond the first line. Treatment for DLBCL, particularly for transplant-ineligible patients, remains challenging.