Key Points: Expansion of PD-1+ CD3−CD56hiCD16-ve NK cells and PD-L1+ monocytes/macrophages is more prominent in cHL than DLBCL. PD-1 blockade reverses the immune evasion mediated by the interaction of PD-1+ NK cells and PD-L1+ monocytes/macrophages.

Blockade of the PD-1 axis has modest efficacy in diffuse large B-cell lymphoma (DLBCL), but data regarding LAG3 are sparse. The impact of LAG3 digital gene expression was tested in 309 patients with DLBCL treated with standard chemoimmunotherapy. Cellular distribution of LAG3 protein was determined by immunohistochemistry and flow cytometry. In tumor-infiltrating lymphocytes (TILs), LAG3 expression was highest on CD4+ regulatory T cells (Tregs) and was also highly expressed on CD8+ T cells compared with CD4+ non-Tregs (both P = .008). LAG3high TILs were enriched in PD-1 and TIM-3. LAG3 was also expressed on a proportion of malignant B cells, and these patients had significantly higher LAG3 messenger RNA in their biopsies (P = .03). LAG3high gene expression was associated with inferior survival in discovery/validation cohorts, independent of cell of origin and the international prognostic index. Patients who were PD-L1high were fivefold more likely to be LAG3high (P < .0001). Patients who were LAG3high/PD-L1high had an inferior progression-free survival (P = .011) and overall survival (P = .005) compared with patients who were LAG3low/PD-L1high. Digital spatial protein analysis confirms LAG3 expression on T cells and, surprisingly, tumor-associated macrophages (TAMs) at higher levels than found on CD20+ B cells in the tumor microenvironment. LAG3 is frequently expressed on CD4+ Tregs and CD8+ TILs, typically with other immune checkpoints, and is also present in a proportion of malignant B cells in DLBCL and in areas enriched for TAMs. LAG3high expression is associated with poor outcome independent of conventional prognosticators.

The treatment of patients with Bing-Neel syndrome (BNS) is not standardized. We included patients with Waldenström macroglobulinemia (WM) and a radiologic and/or cytologic diagnosis of BNS treated with ibrutinib monotherapy. Response assessment was based on criteria for BNS from the 8th International Workshop for WM. Survival from BNS diagnosis (BNS survival), survival from ibrutinib initiation to last follow-up or death (ibrutinib survival), and time from ibrutinib initiation to ibrutinib discontinuation for toxicity, progression, or death (event-free survival [EFS]) were estimated. Twenty-eight patients were included in our study. The median age at BNS diagnosis was 65 years. Ibrutinib was the first line of treatment for BNS in 39% of patients. Ibrutinib was administered orally at a dose of 560 and 420 mg once daily in 46% and 54% of patients, respectively; symptomatic and radiologic improvements were seen in 85% and 60% of patients within 3 months of therapy. At best response, 85% of patients had improvement or resolution of BNS symptoms, 83% had improvement or resolution of radiologic abnormalities, and 47% had cleared the disease in the cerebrospinal fluid. The 2-year EFS rate with ibrutinib was 80% (95% confidence interval [CI], 58%-91%), the 2-year ibrutinib survival rate was 81% (95% CI, 49%-94%), and the 5-year BNS survival rate was 86% (95% CI, 63%-95%). Ibrutinib therapy is effective in patients with BNS and should be considered as a treatment option in these patients.

Risk-stratification of diffuse large B-cell lymphoma (DLBCL) requires identification of patients with disease that is not cured, despite initial treatment with R-CHOP. The prognostic importance of the revised International Prognostic Index (R-IPI) and cell of origin of the malignant B cell are established in DLBCL. We aimed to develop a novel, easily applicable, tissue-based prognostic biomarker based on quantification of the tumour microenvironment that is independent of and additive to the R-IPI and cell of origin. We performed digital hybridisation on the NanoString platform to assess the relation between immune effector and inhibitory (checkpoint) genes in 252 formalin-fixed, paraffin-embedded DLBCL tissue specimens obtained from patients treated with R-CHOP. We used a tree-based survival model to quantify net antitumoral immunity (using ratios of immune effector to checkpoint genes) and to generate a cutoff as an outcome predictor in 158 of the 252 patients. We validated this model in tissue (n=233) and blood (n=140) samples from two independent cohorts treated with R-CHOP. T-cell and NK-cell immune effector molecule expression correlated with tumour-associated macrophage and PD-1/PD-L1 axis markers, consistent with malignant B cells triggering a dynamic checkpoint response to adapt to and evade immune surveillance. The ratio of CD4*CD8 to (CD163:CD68[M2])*PD-L1 was better able to stratify overall survival than was any one immune marker or combination, distinguishing groups with disparate 4-year overall survival. 94 (59%) of 158 patients had a score above the cutoff and 4-year overall survival of 92·1% (95% CI 82·9-96·7), and the remaining 64 (41%) patients had a score below the cutoff and 4-year overall survival of 47·0% (32·8-60·5; hazard ratio [HR] 8·3, 95% CI 4·3-17·3; p<0·0001). The CD4*CD8:M2*PD-L1 immune ratio was independent of and added to the R-IPI and cell of origin. Tissue findings in the independent tissue cohort accorded with those in our initial tissue cohort. 139 (60%) of 233 patients had a score above the cutoff and 4-year overall survival of 75·6% (95% CI 64·6-83·6), with the remaining 94 (40%) patients having a score below the cutoff (63·5% [52·5-72·7]; HR 1·9, 95% CI 1·1-3·3; p=0·0067). Ratios of immune effectors to checkpoints augment the cell of origin and R-IPI in DLBCL and are applicable to paraffin-embedded biopsy specimens. These findings might have potential implications for selection of patients for checkpoint blockade within clinical trials. Leukaemia Foundation of Queensland, Kasey-Anne Oklobdzijato Memorial Fund, the Australasian Leukaemia and Lymphoma Group (Malcolm Broomhead Bequest), the Australian Cancer Research Foundation, and the Cancer Council of Queensland.

Purpose: To investigate the relationship between the intra-tumoral T-cell receptor (TCR) repertoire and the tumor microenvironment (TME) in de novo diffuse large B-cell lymphoma (DLBCL) and the impact of TCR on survival. Experimental Design: We performed high-throughput unbiased TCRβ sequencing on a population-based cohort of 92 patients with DLBCL treated with conventional (i.e., non-checkpoint blockade) frontline “R-CHOP” therapy. Key immune checkpoint genes within the TME were digitally quantified by nanoString. The primary endpoints were 4-year overall survival (OS) and progression-free survival (PFS). Results: The TCR repertoire within DLBCL nodes was abnormally narrow relative to non-diseased nodal tissues (P < 0.0001). In DLBCL, a highly dominant single T-cell clone was associated with inferior 4-year OS rate of 60.0% [95% confidence interval (CI), 31.7%–79.6%], compared with 79.8% in patients with a low dominant clone (95% CI, 66.7%–88.5%; P = 0.005). A highly dominant clone also predicted inferior 4-year PFS rate of 46.6% (95% CI, 22.5%–76.6%) versus 72.6% (95% CI, 58.8%–82.4%, P = 0.008) for a low dominant clone. In keeping, clonal expansions were most pronounced in the EBV+ DLBCL subtype that is known to express immunogenic viral antigens and is associated with particularly poor outcome. Increased T-cell diversity was associated with significantly elevated PD-1, PD-L1, and PD-L2 immune checkpoint molecules. Conclusions: Put together, these findings suggest that the TCR repertoire is a key determinant of the TME. Highly dominant T-cell clonal expansions within the TME are associated with poor outcome in DLBCL treated with conventional frontline therapy. Clin Cancer Res; 23(7); 1820–8. ©2016 AACR.

Patients with Waldenström macroglobulinemia (WM) lacking activating mutations in the MYD88 gene (MYD88WT) have demonstrated relatively poor outcomes to ibrutinib monotherapy, with no major responses reported in a phase 2 pivotal study. Zanubrutinib is a novel, selective Bruton tyrosine kinase (BTK) inhibitor designed to maximize BTK occupancy and minimize off-target activity. The ASPEN study consisted of a randomized comparison of zanubrutinib and ibrutinib efficacy and safety in patients with WM who have the MYD88 mutation, as well as a separate cohort of patients without MYD88 mutation (MYD88WT) or with unknown mutational status who received zanubrutinib. Results from the latter single-arm cohort are reported herein. Efficacy endpoints included overall, major and complete (CR) or very good partial response (VGPR) rates, progression-free survival (PFS), duration of response (DOR), and overall survival (OS). Twenty-eight patients (23 relapsed/refractory; 5 treatment-naïve) were enrolled, including 26 with centrally confirmed MYD88WT disease and 2 with unknown MYD88 mutational status. At a median follow-up of 17.9 months, 7 of 26 MYD88WT patients (27%) had achieved a VGPR and 50% a major response (partial response or better); there were no CRs. At 18 months, the estimated PFS and OS rates were 68% and 88%, respectively, while the median DOR had not been reached. Two patients discontinued zanubrutinib due to adverse events. Treatment-emergent hypertension, atrial fibrillation, and major hemorrhages were reported in 3, 1 and 2 patients (including 1 concurrent with enoxaparin therapy), respectively. Results of this substudy demonstrate that zanubrutinib monotherapy can induce high quality responses in patients with MYD88WT WM. This trial is registered on www.clinicaltrials.gov as NCT #03053440.