Integrated single cell analysis reveals co-evolution of malignant B cells and tumor micro-environment in transformed follicular lymphoma.

Histological transformation of follicular lymphoma (FL) to aggressive forms is associated with poor outcome. Phenotypic consequences of this evolution and its impact on the tumor microenvironment (TME) remain unknown. We perform single-cell whole genome sequencing (scWGS) and transcriptome sequencing (scWTS) of 11 paired pre/post-transformation patient samples and scWTS of additional samples from patients without transformation. Our analysis reveals evolutionary dynamics of transformation at single-cell resolution, highlighting a shifting TME landscape, with an emerging immune-cell exhaustion signature, co-evolving with the shifting malignant B phenotype in a regulatory ecosystem. Integration of scWGS and scWTS identifies malignant cell pathways upregulated during clonal tumor evolution. Using multi-color immunofluorescence, we transfer these findings to a TME-based transformation biomarker, subsequently validated in two independent pretreatment cohorts. Taken together, our results provide a comprehensive view of the combined genomic and phenotypic evolution of malignant cells during transformation and shifting crosstalk between malignant cells and the TME.

Efficacy of CAR T-cell therapy is not impaired by previous bispecific antibody treatment in large B-cell lymphoma.

ABSTRACT: In this retrospective study, chimeric antigen receptor T cells remained effective in patients with relapsed/refractory large B-cell lymphoma after prior exposure to bispecific antibodies (BsAbs) targeting different antigens. These results are relevant to clinical practice, particularly given the increasing use of BsAbs in earlier treatment lines.

Obinutuzumab vs rituximab for transplant-eligible patients with mantle cell lymphoma.

ABSTRACT: Obinutuzumab (O) and rituximab (R) are 2 CD antibodies that have never been compared in a prospective randomized trial of mantle cell lymphoma (MCL). Herein, we report the long-term outcome of the LyMa-101 trial, in which newly diagnosed patients with MCL were treated with chemotherapy plus O before transplantation, followed by O maintenance (O group). We then compared these patients with those treated with the same treatment design with R instead of O (R group). A propensity score matching (PSM) was used to compare the 2 populations (O vs R groups) in terms of measurable residual disease (MRD) at the end of induction (EOI), progression-free survival (PFS), and overall survival (OS). In LyMa-101, the estimated 5-year PFS and OS after inclusion (n = 85) were 83.4% (95% confidence interval [CI], 73.5-89.8) and 86.9% (95% CI, 77.6-92.5), respectively. At EOI, patients treated in the O group had more frequent bone marrow MRD negativity than those treated in the R group (83.1% vs 63.4%; χ2, P = .007). PSM resulted in 2 sets of 82 patients with comparable characteristics at inclusion. From treatment initiation, the O group had a longer estimated 5-year PFS (P = .029; 82.8% vs 66.6%; hazard ratio [HR], 1.99; 95% confidence interval (CI), 1.05-3.76) and OS (P = .039; 86.4% vs 71.4%; HR, 2.08; 95% CI, 1.01-4.16) compared with the R group. Causes of death were comparable in the 2 groups, the most common cause being lymphoma. O before transplantation and in maintenance provides better disease control and enhances PFS and OS compared with R in transplant-eligible patients with MCL. These trials were registered at www.clinicaltrials.gov as #NCT00921414 and NCT02896582.

Unraveling MCL biology to understand resistance and identify vulnerabilities.

Mantle cell lymphoma (MCL) is a rare (5-7%), aggressive B-cell non-Hodgkin's lymphoma with well-defined hallmarks (e.g. Cyclin D1, SOX11), and whose expansion is highly dependent on the tumor microenvironment (TME). Parallel drastic progresses in the understanding of the lymphomagenesis and improved treatments led to paradigm shift in this B-cell malignancy with now prolonged disease-free survival after intensive chemotherapy and anti-CD20 based maintenance. However, this toxic strategy is not applicable in frail or elderly patients and a small but significant part of the cases will present a refractory disease representing unmet medical needs. Importantly, the field has recently seen the rapid emergence of targeted and immune-based strategies with effective combinations relying on biological rationales to overcome malignant plasticity and intratumor heterogeneity. In this review, we expose how unraveling the biology of MCL allows to better understand the therapeutic resistances and to identify neo-vulnerabilities of tumors, which are essential to offer efficient novel strategies for high-risk patients. We first highlight the tumor intrinsic resistance mechanisms, and associated Achilles heels within various pathways such as NFkB, mitochondrial apoptosis, DNA repair or epigenetic regulators. We then place the tumor in its complex ecosystem to decipher the dialog with the multiple TME components and show how the resulting protumoral signals could be disrupted with innovative therapeutics strategies. Finally, we discuss how these progresses could be integrated in a personalized approach in MCL.

Long-Term Follow-Up of Rituximab Maintenance in Young Patients With Mantle-Cell Lymphoma Included in the LYMA Trial: A LYSA Study.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned coprimary or secondary analyses are not yet available. Clinical trial updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.The LYMA trial demonstrated the benefit of rituximab maintenance (RM) in first-line young patients with mantle-cell lymphoma. In this prolonged follow-up of 7.5 years (95% CI, 7.4 to 7.7) from inclusion, the median progression-free survival (PFS) and overall survival (OS) for the full population were not reached (NR) with a 7-year PFS of 55.5% (95% CI, 49.5 to 61) and OS of 69.5% (95% CI, 63.8 to 74.5). The EFS remained statistically superior in favor of RM (median NR v 5.8 years, P < .0001; HR, 0.39 [95% CI, 0.52 to 0.6] and 7-year estimate, 76.2% versus 46% for RM and observation, respectively). Similarly, RM prolonged PFS (estimated PFS at 7 years, 78.5% v 47.4% and HR, 0.36 [95% CI, 0.23 to 0.56] for RM and observation, respectively, P < .0001). The 7-year OS estimate was 83.2% versus 72.2%, respectively (P = .088, HR, 0.63 [95% CI, 0.37 to 1.08]). Cause of death was not significantly distinct between the two groups, with lymphoma being the leading cause with a very low rate of infection-related death. Overall, the PFS benefit of RM after autologous stem cell transplantation remains after 7-year follow-up, and RM was not associated with an increase in infection-related mortality, making this strategy a safe standard of care with long-term follow-up.