Rosenwald, Andreas

One-third of peripheral T-cell lymphomas are “not otherwise specified” (PTCL-NOS), but they have been subdivided into 2 subgroups based on gene expression profiling. Amador and colleagues generated an immunohistochemical algorithm that parallels the molecular separation of PTCL-NOS and provides useful prognostic information.

Abstract Primary mediastinal large B-cell lymphoma (PMBCL) is recognized as a distinct entity in the World Health Organization classification. Currently, the diagnosis relies on consensus of histopathology, clinical variables, and presentation, giving rise to diagnostic inaccuracy in routine practice. Previous studies have demonstrated that PMBCL can be distinguished from subtypes of diffuse large B-cell lymphoma (DLBCL) based on gene expression signatures. However, requirement of fresh-frozen biopsy material has precluded the transfer of gene expression–based assays to the clinic. Here, we developed a robust and accurate molecular classification assay (Lymph3Cx) for the distinction of PMBCL from DLBCL subtypes based on gene expression measurements in formalin-fixed, paraffin-embedded tissue. A probabilistic model accounting for classification error, comprising 58 gene features, was trained on 68 cases of PMBCL and DLBCL. Performance of the model was subsequently evaluated in an independent validation cohort of 158 cases and showed high agreement of the Lymph3Cx molecular classification with the clinicopathological diagnosis of an expert panel (frank misclassification rate, 3.8%). Furthermore, we demonstrate reproducibility of the assay with 100% concordance of subtype assignments at 2 independent laboratories. Future studies will determine Lymph3Cx’s utility for routine diagnostic purposes and therapeutic decision making.

TPS7571 Background: Patients ineligible for stem cell transplantation (SCT) or who relapse after SCT, and those who fail to respond to second-line or salvage chemotherapy, represent an unmet medical need for which new therapeutic strategies are required. MOR208 is a novel Fc-enhanced, humanized, monoclonal antibody directed against CD19. Significant single-agent activity of MOR208 in patients with R-R DLBCL (Jurczak et al., J Clin Oncol 34, 2016 [suppl; abstr 7545]) and enhancement of MOR208-mediated cytotoxicity by BEN in preclinical studies, provide a strong rationale to study MOR208 + BEN in patients with R-R DLBCL. Methods: B-MIND is a randomized (1:1), two-arm, multicenter, open-label, adaptive design, phase II/III study of MOR208 + BEN vs RTX + BEN in adult patients with histologically confirmed DLBCL who have relapsed after or are refractory to 1 to 3 prior lines of therapy and who are not candidates for high-dose chemotherapy and autologous SCT. At least 1 prior therapy line must have included a CD20-targeted therapy. Other key inclusion criteria: age ≥18 years; measurable disease; availability of tumor tissue for central pathology review; ECOG 0–2, and adequate major organ systems function. Key exclusion criteria: primary refractory DLBCL; central nervous system involvement, and known double/triple hit DLBCL genetics. The safety of the combination will be assessed in an initial phase II evaluation. Treatment will comprise 6 cycles of MOR208 (12 mg/kg IV) + BEN (90 mg/m2 IV) or RTX 375 mg/m2 IV + BEN. Patients achieving a response after cycle 6 will continue to receive antibody treatment for up to 18 additional cycles. Primary endpoint: progression-free survival (PFS); secondary endpoints include: best overall response, overall survival, safety, quality of life, immunogenicity and pharmacokinetics. Enrollment of 330 patients is anticipated in Europe, US and Asia-Pacific countries. Fourteen patients have been randomized to date. Clinical trial information: NCT02763319.

SummaryMantle cell lymphoma (MCL) is still considered incurable and the course of the disease is highly variable. Established risk factors include the Mantle Cell Lymphoma International Prognostic Index (MIPI) and the quantification of the proliferation rate of the tumour cells, e.g. by Ki‐67 immunohistochemistry. In this study, we aimed to validate the prognostic value of the gene expression‐based MCL35 proliferation assay in patient cohorts from randomized trials of the European Mantle Cell Lymphoma Network. Using this assay, we analysed the gene expression proliferation signature in routine diagnostic lymph node specimens from MCL Younger and MCL Elderly trial patients, and the calculated MCL35 score was used to assign MCL patients to low (61%), standard (27%) or high (12%) risk groups with significantly different outcomes. We confirm here in our prospective clinical trial cohort of MCL patients, that the MCL35 assay is strongly prognostic, providing additional information to the Ki‐67 index and the MIPI. Thus, this robust assay may assist in making treatment decisions or in devising risk‐adapted prospective clinical trials in the future.

SummaryPatients with mantle cell lymphoma (MCL) generally have a dismal prognosis. Intensified induction treatment with rituximab and high dose cytarabine (R_HDAC), and consolidation with high‐dose therapy with autologous stem cell support has resulted in 10‐year overall survival (OS) higher than 60%. However, the clinical course varies. Diagnostic tools capable of stratifying patients include the MCL International Prognostic Index (MIPI), gene expression‐based proliferation signature, Ki‐67 proliferation index or tumour cell morphology. Here, we tested the performance of a newly developed Nanostring‐based RNA expression‐based proliferation assay (MCL35) on formalin‐fixed paraffin‐embedded tumour tissue from younger patients recruited in or treated according to Nordic MCL protocols compared to the prognosticators listed above. Seventy‐four patients were included and the assay performed well in all cases except four, which had inadequate RNA quality. The patients were evenly distributed in the MCL35 low‐, intermediate‐ and high‐risk categories. MCL35 low‐ and intermediate‐ risk groups had overlapping progression‐free survival (PFS), while patients in the high‐risk category had significantly inferior PFS. Combining MCL35 with MIPI or the MIPI‐C (MIPI with the addition of binary Ki67 score +/−30%) showed a better discrimination than either assessment alone. In conclusion, the MCL35 assay alone or combined with MIPI or MIPI‐C scores can identify patients who still have a dismal outcome despite intensified treatment.

Key PointsA new molecular assay identifies conventional and leukemic nonnodal MCL with differing clinicobiological features. The integration of the novel assay with genetic alterations identifies subsets of MCL patients with different management and outcome.

Key Points HGBL-DH/TH makes up 8% of de novo DLBCL, with HGBL-DH/TH with BCL2 rearrangement being a GCB phenomenon. Restricting FISH testing to tumors with dual protein expression and GCB subtype results in testing <15% of tumors, but missing ∼35% of HGBL-DH/TH.