Translating the Biology of Diffuse Large B-cell Lymphoma Into Treatment

Real-world patient characteristics, treatment patterns, and treatment outcomes of patients with diffuse large B-cell lymphoma by line of therapy

BACKGROUND

Although initial treatment of diffuse large B-cell lymphoma (DLBCL) with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) can be effective, up to 50% of patients will develop refractory or relapsed (R/R) disease. This study aimed to provide contemporary data on characteristics, treatment patterns, and outcomes for R/R-DLBCL.

METHODS

Patients with incident (January 2016 to March 2021) DLBCL age ≥18 years who initiated first-line (1L) therapy were identified from the COTA real-world database. Baseline characteristics, treatment patterns, and real-world outcomes, including time to next treatment (rwTTNT) and overall survival (rwOS), were assessed for the study population and by line of therapy (LOT).

RESULTS

A total of 1347 eligible DLBCL patients were identified. Of these, 340 (25.2%) proceeded to receive 2L, of whom 141 (41.5%) proceeded to receive 3L, of whom 51 (36.2%) proceeded to receive 4L+. Most common treatments were R-CHOP in 1L (63.6%), stem cell transplant (SCT) in 2L (17.9%), polatuzumab vedotin, bendamustine, and rituximab (Pola-BR) in 3L (9.9%), and chimeric antigen receptor T-cell therapy (CAR-T) in 4L (11.8%). Treatment patterns were more variable in later LOTs. One- and 3-year rwOS from 1L initiation were 88.5% and 78.4%, respectively. Patients who received later LOTs experienced numerically lower 1- and 3-year rwOS (from 2L initiation: 62.4% and 46.4%, respectively).

CONCLUSIONS

In this real-world analysis, 25.2% of patients experienced R/R-DLBCL after 1L with poor outcomes. Given the findings of this study, there is a high unmet need for novel, safe, and effective treatment options for patients with R/R DLBCL.

Molecular assessment of intratumoral immune cell subsets and potential mechanisms of resistance to odronextamab, a CD20×CD3 bispecific antibody, in patients with relapsed/refractory B-cell non-Hodgkin lymphoma

BACKGROUND

Patients with relapsed/refractory B-cell non-Hodgkin lymphoma (R/R B-NHL) have a significant need for effective treatment options. Odronextamab is an Fc-silenced, human, CD20×CD3 bispecific antibody that targets CD20-expressing cells via T-cell-mediated cytotoxicity independent of T-cell/major histocompatibility complex interaction. Phase I results in patients with R/R B-NHL demonstrated that odronextamab monotherapy could achieve deep and durable responses with a generally manageable safety profile (ELM-1; NCT02290951). As part of a biomarker analysis of the same study, we investigated potential biomarkers and mechanisms of resistance to odronextamab.

METHODS

Patients with R/R B-NHL enrolled in ELM-1 received one time per week doses of intravenous odronextamab for 4×21 day cycles, then doses every 2 weeks thereafter. Patient tumor biopsies were obtained at baseline, on-treatment, and at progression. Immune cell markers were analyzed by immunohistochemistry, flow cytometry, single-cell RNA sequencing, and whole genome sequencing.

RESULTS

Baseline tumor biopsies showed that almost all patients had high proportions of B cells that expressed the CD20 target antigen, whereas expression of other B-cell surface antigens (CD19, CD22, CD79b) was more variable. Responses to odronextamab in patients with diffuse large B-cell lymphoma were not related to the relative level of baseline CD20 expression, cell of origin, or high-risk molecular subtype. A potential link was observed between greater tumor programmed cell death-ligand 1 expression and increased likelihood of response to odronextamab. Similarly, a trend was observed between clinical response and increased levels of CD8 T cells and regulatory T cells at baseline. We also identified an on-treatment pharmacodynamic shift in intratumoral immune cell subsets. Finally, loss of CD20 expression through inactivating gene mutations was identified as a potential mechanism of resistance in patients who were treated with odronextamab until progression, as highlighted in two detailed patient cases reported here.

CONCLUSIONS

This biomarker analysis expands on clinical findings of odronextamab in patients with R/R B-NHL, providing verification of the suitability of CD20 as a therapeutic target, as well as evidence for potential mechanisms of action and resistance.

Role of RNA Splicing Mutations in Diffuse Large B Cell Lymphoma

Ribonucleic acid splicing is a crucial process to create a mature mRNA molecule by removing introns and ligating exons. This is a highly regulated process, but any alteration in splicing factors, splicing sites, or auxiliary components affects the final products of the gene. In diffuse large B-cell lymphoma, splicing mutations such as mutant splice sites, aberrant alternative splicing, exon skipping, and intron retention are detected. The alteration affects tumor suppression, DNA repair, cell cycle, cell differentiation, cell proliferation, and apoptosis. As a result, malignant transformation, cancer progression, and metastasis occurred in B cells at the germinal center. B-cell lymphoma 7 protein family member A (BCL7A), cluster of differentiation 79B (CD79B), myeloid differentiation primary response gene 88 (MYD88), tumor protein P53 (TP53), signal transducer and activator of transcription (STAT), serum- and glucose-regulated kinase 1 (SGK1), Pou class 2 associating factor 1 (POU2AF1), and neurogenic locus notch homolog protein 1 (NOTCH) are the most common genes affected by splicing mutations in diffuse large B cell lymphoma.

Outcomes of Autologous Hematopoietic Cell Transplantation in Older Patients with Diffuse Large B Cell Lymphoma

Data for outcomes after autologous hematopoietic cell transplantation (auto-HCT) in diffuse large B-cell lymphoma (DLBCL) patients ≥70 years are limited. Auto-HCT is feasible in older DLBCL patients. Using the Center for International Blood and Marrow Transplant Research database, we compared outcomes of auto-HCT in DLBCL patients aged 60 to 69 years (n = 363) versus ≥70 years (n = 103) between 2008 and 2019. Non-relapse mortality (NRM), relapse/progression (REL), progression-free survival (PFS), and overall survival (OS) were modeled using Cox proportional hazards models. All patients received BEAM conditioning (carmustine, etoposide, cytosine arabinoside and melphalan). On univariate analysis, in the 60 to 69 years versus ≥70 years cohorts, 100-day NRM was 3% versus 4%, 5-year REL was 47% versus 45%, 5-year PFS 40% versus 38% and 5-year OS 55% versus 41%, respectively. On multivariate analysis, patients ≥70 had no significant difference in NRM (hazard ratio [HR] 1.43, 95% confidence interval [CI] 0.85-2.39), REL (HR 1.11, 95% CI 0.79-1.56), PFS (HR 1.23, 95% CI 0.92-1.63) compared to patients 60 to 69 years. Patients ≥70 years had a higher mortality (HR 1.39, 95% CI 1.05-1.85, p=0.02), likely because of inferior post-relapse OS in this cohort (HR 1.82, 95% CI 1.27-2.61, P = .001). DLBCL was the major cause of death in both cohorts (62% versus 59%). Older patients should not be denied auto-HCT solely on the basis of chronological age.