Molecular classification of aggressive lymphomas-past, present, future

Follicular lymphoma comprises germinal center-like and memory-like molecular subtypes with prognostic significance

ABSTRACT

A robust prognostic and biological classification for newly diagnosed follicular lymphoma (FL) using molecular profiling remains challenging. FL tumors from patients treated in the RELEVANCE trial with rituximab-chemotherapy (R-chemo) or rituximab-lenalidomide (R2) were analyzed using RNA sequencing, DNA sequencing, immunohistochemistry (IHC), and/or fluorescence in situ hybridization. Unsupervised gene clustering identified 2 gene expression signatures (GSs) enriched in normal memory (MEM) B cells and germinal center (GC) B-cell signals, respectively. These 2 GSs were combined into a 20-gene predictor (FL20) to classify patients into MEM-like (n = 160) or GC-like (n = 164) subtypes, which also displayed different mutational profiles. In the R-chemo arm, patients with MEM-like FL had significantly shorter progression-free survival (PFS) than patients with GC-like FL (hazard ratio [HR], 2.13; P = .0023). In the R2 arm, both subtypes had comparable PFS, demonstrating that R2 has a benefit over R-chemo for patients with MEM-like FL (HR, 0.54; P = .011). The prognostic value of FL20 was validated in an independent FL cohort with R-chemo treatment (GSE119214 [n = 137]). An IHC algorithm (FLcm) that used FOXP1, LMO2, CD22, and MUM1 antibodies was developed with significant prognostic correlation with FL20. These data indicate that FL tumors can be classified into MEM-like and GC-like subtypes that are biologically distinct and clinically different in their risk profile. The FLcm assay can be used in routine clinical practice to identify patients with MEM-like FL who might benefit from therapies other than R-chemo, such as the R2 combination. This trial was registered at www.clinicaltrials.gov as #NCT01476787 and #NCT01650701.

Epcoritamab in relapsed/refractory large B-cell lymphoma: 2-year follow-up from the pivotal EPCORE NHL-1 trial

Primary results (median follow-up, 10.7 months) from the pivotal EPCORE® NHL-1 study in relapsed or refractory (R/R) large B-cell lymphoma (LBCL) demonstrated deep, durable responses with epcoritamab, a CD3xCD20 bispecific antibody, when used as monotherapy. We report long-term efficacy and safety results in patients with LBCL (N = 157; 25.1-month median follow-up). As of April 21, 2023, overall response rate was 63.1% and complete response (CR) rate was 40.1%. Estimated 24-month progression-free survival (PFS) and overall survival (OS) rates were 27.8% and 44.6%, respectively. An estimated 64.2% of complete responders remained in CR at 24 months. Estimated 24-month PFS and OS rates among complete responders were 65.1% and 78.2%, respectively. Of 119 minimal residual disease (MRD)-evaluable patients, 45.4% had MRD negativity, which correlated with longer PFS and OS. CR rates were generally consistent across predefined subgroups: 36% prior chimeric antigen receptor (CAR) T-cell therapy, 32% primary refractory disease, and 37% International Prognostic Index ≥3. The most common treatment-emergent adverse events were cytokine release syndrome (51.0%), pyrexia (24.8%), fatigue (24.2%), and neutropenia (23.6%). These results underscore the long-term benefit of epcoritamab for treating R/R LBCL with deep responses across subgroups, including patients with hard-to-treat disease and expected poor prognosis (ClinicalTrials.gov Registration: NCT03625037).

Spleen tyrosine kinase (SYK): an emerging target for the assemblage of small molecule antitumor agents

INTRODUCTION

Spleen tyrosine kinase (SYK), a nonreceptor tyrosine kinase, has emerged as a vital component in the complex symphony of cancer cell survival and division. SYK activation (constitutive) is documented in various B-cell malignancies, and its inhibition induces programmed cell death. In some instances, it also acts as a tumor suppressor.

AREAS COVERED

Involvement of the SYK in the cancer growth, specifically in the progression of chronic lymphocytic leukemia (CLL), diffuse large B cell lymphomas (DLBCLs), acute myeloid leukemia (AML), and multiple myeloma (MM) is discussed. Therapeutic strategies to target SYK in cancer, including investigational SYK inhibitors, combinations of SYK inhibitors with other drugs targeting therapeutically relevant targets, and recent advancements in constructing new structural assemblages as SYK inhibitors, are also covered.

EXPERT OPINION

The SYK inhibitor field is currently marred by the poor translation rate of SYK inhibitors from preclinical to clinical studies. Also, dose-limited toxicities associated with the applications of SYK inhibitors have been evidenced. Thus, the development of new SYK inhibitory structural templates is in the need of the hour. To accomplish the aforementioned, interdisciplinary teams should incessantly invest efforts to expand the size of the armory of SYK inhibitors.

Improving outcomes of childhood and young adult non-Hodgkin lymphoma: 25 years of research and collaboration within the framework of the European Intergroup for Childhood Non-Hodgkin Lymphoma

The European Intergroup for Childhood Non-Hodgkin Lymphoma (EICNHL) was established 25 years ago with the goal to facilitate clinical trials and research collaborations in the field both within Europe and worldwide. Since its inception, much progress has been made whereby major improvements in outcomes have been achieved. In this Review, we describe the different diagnostic entities of non-Hodgkin lymphoma in children and young adults describing key features of each entity and outlining clinical achievements made in the context of the EICNHL framework. Furthermore, we provide an overview of advances in biopathology with an emphasis on the role of biological studies and how they have shaped available treatments. Finally, for each entity, we describe future goals, upcoming clinical trials, and highlight areas of research that require our focus going forward.

Epcoritamab, a Novel, Subcutaneous CD3xCD20 Bispecific T-Cell-Engaging Antibody, in Relapsed or Refractory Large B-Cell Lymphoma: Dose Expansion in a Phase I/II Trial

PURPOSE

Epcoritamab is a subcutaneously administered CD3xCD20 T-cell-engaging, bispecific antibody that activates T cells, directing them to kill malignant CD20⁺ B cells. Single-agent epcoritamab previously demonstrated potent antitumor activity in dose escalation across B-cell non-Hodgkin lymphoma subtypes.

PATIENTS AND METHODS

In the dose-expansion cohort of a phase I/II study (ClinicalTrials.gov identifier: NCT03625037), adults with relapsed or refractory CD20⁺ large B-cell lymphoma and at least two prior therapy lines (including anti-CD20 therapies) received subcutaneous epcoritamab in 28-day cycles (once weekly step-up doses in weeks 1-3 of cycle 1, then full doses once weekly through cycle 3, once every 2 weeks in cycles 4-9, and once every 4 weeks in cycle 10 and thereafter) until disease progression or unacceptable toxicity. The primary end point was overall response rate by the independent review committee.

RESULTS

As of January 31, 2022, 157 patients were treated (median age, 64 years [range, 20-83]; median of three [range, 2-11] prior therapy lines; primary refractory disease: 61.1%; prior chimeric antigen receptor (CAR) T-cell exposure: 38.9%). At a median follow-up of 10.7 months, the overall response rate was 63.1% (95% CI, 55.0 to 70.6) and the complete response rate was 38.9% (95% CI, 31.2 to 46.9). The median duration of response was 12.0 months (among complete responders: not reached). Overall and complete response rates were similar across key prespecified subgroups. The most common treatment-emergent adverse events were cytokine release syndrome (49.7%; grade 1 or 2: 47.1%; grade 3: 2.5%), pyrexia (23.6%), and fatigue (22.9%). Immune effector cell-associated neurotoxicity syndrome occurred in 6.4% of patients with one fatal event.

CONCLUSION

Subcutaneous epcoritamab resulted in deep and durable responses and manageable safety in highly refractory patients with large B-cell lymphoma, including those with prior CAR T-cell exposure.

Classifying Germinal Center Derived Lymphomas-Navigate a Complex Transcriptional Landscape

Classification of lymphoid neoplasms is based mainly on histologic, immunologic, and (rarer) genetic features. It has been supplemented by gene expression profiling (GEP) in the last decade. Despite the considerable success, particularly in associating lymphoma subtypes with specific transcriptional programs and classifier signatures of up- or downregulated genes, competing molecular classifiers were often proposed in the literature by different groups for the same classification tasks to distinguish, e.g., BL versus DLBCL or different DLBCL subtypes. Moreover, rarer sub-entities such as MYC and BCL2 "double hit lymphomas" (DHL), IRF4-rearranged large cell lymphoma (IRF4-LCL), and Burkitt-like lymphomas with 11q aberration pattern (mnBLL-11q) attracted interest while their relatedness regarding the major classes is still unclear in many respects. We explored the transcriptional landscape of 873 lymphomas referring to a wide spectrum of subtypes by applying self-organizing maps (SOM) machine learning. The landscape reveals a continuum of transcriptional states activated in the different subtypes without clear-cut borderlines between them and preventing their unambiguous classification. These states show striking parallels with single cell gene expression of the active germinal center (GC), which is characterized by the cyclic progression of B-cells. The expression patterns along the GC trajectory are discriminative for distinguishing different lymphoma subtypes. We show that the rare subtypes take intermediate positions between BL, DLBCL, and FL as considered by the 5th edition of the WHO classification of haemato-lymphoid tumors in 2022. Classifier gene signatures extracted from these states as modules of coregulated genes are competitive with literature classifiers. They provide functional-defined classifiers with the option of consenting redundant classifiers from the literature. We discuss alternative classification schemes of different granularity and functional impact as possible avenues toward personalization and improved diagnostics of GC-derived lymphomas.

Precision diagnostics in lymphomas - Recent developments and future directions

Genetics is an integral part of the clinical diagnostics of lymphomas that improves disease subclassification and patient risk-stratification. With the introduction of high-throughput sequencing technologies, a rapid, in-depth portrayal of the genomic landscape in major lymphoma entities was achieved. Whilst a few lymphoma entities were characterized by a predominant gene mutation (e.g. Waldenström's macroglobulinemia and hairy cell leukemia), the vast majority demonstrated a very diverse genetic landscape with a high number of recurrent gene mutations (e.g. chronic lymphocytic leukemia and diffuse large B cell lymphoma), indeed reflecting the great clinical heterogeneity among lymphomas. These studies have allowed better understanding of the ontogeny and evolution of different lymphomas, while also identifying new genetic markers that can complement lymphoma diagnostics and improve prognostication. However, despite these efforts, there is still a limited number of gene mutations with predictive impact that can guide treatment selection. In this review, we will highlight clinically relevant diagnostic, prognostic and predictive markers in lymphomas that are used today in routine diagnostics. We will also discuss how comprehensive genomic characterization using broad sequencing panels, allowing for the simultaneous detection of different types of genetic aberrations, may aid future development of precision diagnostics in lymphomas. This may in turn pave the way for the implementation of tailored precision therapy strategies at the individual patient level.