Measurable Residual Disease Testing Following Nonintensive Chemoimmunotherapy is Predictive of Need for Maintenance Therapy in Previously Untreated Mantle Cell Lymphoma: A Wisconsin Oncology Network Study.

INTRODUCTION: Obinutuzumab is hypothesized to improve progression-free survival (PFS) combined with bendamustine induction in mantle cell lymphoma (MCL). Measurable-residual disease (MRD) testing may predict benefit from maintenance therapy. METHODS: Adults (≥ 18 years) with untreated MCL ineligible for intensive therapies received 4 to 6 cycles of bendamustine + obinutuzumab (BO) followed by consolidation obinutuzumab (CO). Restaging after CO included MRD assessment by next-generation sequencing of bone marrow aspirate (BMA) and peripheral blood (PB). Maintenance obinutuzumab (MO) was omitted for patients with imaging complete response (CR) and MRD-negativity in PB/BMA. All other patients received 8 cycles MO. Primary endpoint is PFS; secondary endpoints are response rates, overall survival, and estimation of MRD status. RESULTS: Twenty-one patients enrolled, with median age 70 years and stage IV disease in 95%. Twenty patients completed BO; 10 patients received MO per protocol. Six patients did not complete MO due to progression (n = 4), infection (n = 1) and carcinoma (n = 1). Overall response is 95% (75% CR, 20% partial response). Concordance rate between post-consolidation MRD testing in PB and BMA was 70%. After a median follow-up of 43.9 months, median PFS is 46.5 months. The observed difference between 2-year PFS in groups receiving MO versus observation was not statistically significant (HR 0.45, 95% CI, 0.10-1.91). Most common grade 3/4 toxicities were neutropenia, leukopenia, and infections. CONCLUSIONS: BO is a tolerable induction regimen with higher rates of CR compared with historical rates with bendamustine + rituximab. Omission of MO did not worsen outcomes in patients achieving MRD-negative status after nonintensive induction/consolidation therapy.

T-Cell Lymphomas, Version 2.2022, NCCN Clinical Practice Guidelines in Oncology.

Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of lymphoproliferative disorders arising from mature T cells, accounting for about 10% of non-Hodgkin lymphomas. PTCL-not otherwise specified is the most common subtype, followed by angioimmunoblastic T-cell lymphoma, anaplastic large cell lymphoma, anaplastic lymphoma kinase-positive, anaplastic large cell lymphoma, anaplastic lymphoma kinase-negative, and enteropathy-associated T-cell lymphoma. This discussion section focuses on the diagnosis and treatment of PTCLs as outlined in the NCCN Guidelines for T-Cell Lymphomas.

NCCN Guidelines Insights: T-Cell Lymphomas, Version 1.2021.

Hepatosplenic T-cell lymphoma (HSTCL) is a rare subtype of T-cell lymphoma associated with an aggressive clinical course and a worse prognosis. HSTCL develops in the setting of chronic immune suppression or immune dysregulation in up to 20% of cases and is most often characterized by spleen, liver, and bone marrow involvement. Diagnosis and management of HSTCL pose significant challenges given the rarity of the disease along with the absence of lymphadenopathy and poor outcome with conventional chemotherapy regimens. These Guidelines Insights focus on the diagnosis and treatment of HSTCL as outlined in the NCCN Guidelines for T-Cell Lymphomas.

NCCN Guidelines Insights: Primary Cutaneous Lymphomas, Version 2.2020.

Mycosis fungoides (MF) is the most common subtype of cutaneous T-cell lymphoma (CTCL), and Sézary syndrome (SS) is a rare erythrodermic and leukemic subtype of CTCL characterized by significant blood involvement. Although early-stage disease can be effectively treated predominantly with skin-directed therapies, systemic therapy is often necessary for the treatment of advanced-stage disease. Systemic therapy options have evolved in recent years with the approval of novel agents such as romidepsin, brentuximab vedotin, and mogamulizumab. These NCCN Guidelines Insights discuss the diagnosis and management of MF and SS (with a focus on systemic therapy).

NCCN Guidelines Insights: T-Cell Lymphomas, Version 2.2018.

Natural killer (NK)/T-cell lymphomas are a rare and distinct subtype of non-Hodgkin's lymphomas. NK/T-cell lymphomas are predominantly extranodal and most of these are nasal type, often localized to the upper aerodigestive tract. Because extranodal NK/T-cell lymphomas (ENKL) are rare malignancies, randomized trials comparing different regimens have not been conducted to date and standard therapy has not yet been established for these patients. These NCCN Guidelines Insights discuss the recommendations for the diagnosis and management of patients with ENKL as outlined in the NCCN Guidelines for T-Cell Lymphomas.

Long-term outcomes, secondary malignancies and stem cell collection following bendamustine in patients with previously treated non-Hodgkin lymphoma.

Despite the long history of bendamustine as treatment for indolent non-Hodgkin lymphoma, long-term efficacy and toxicity data are minimal. We reviewed long-term data from three clinical trials to characterize the toxicity and efficacy of patients receiving bendamustine. Data were available for 149 subjects at 21 sites. The median age was 60 years at the start of bendamustine (range 39-84), and patients had received a median of 3 prior therapies. The histologies included grades 1-2 follicular lymphoma (FL; n = 73), grade 3 FL (n = 23), small lymphocytic lymphoma (n = 20), marginal zone lymphoma (n = 15), mantle cell lymphoma (n = 9), transformed lymphomas (n = 5), lymphoplasmacytic lymphoma (n = 2) and not reported (n = 2). The median event-free survival was 14·1 months. Nine of 12 attempted stem cell collections were successful. With a median follow-up of 8·9 years, 23 patients developed 25 cancers, including 8 patients with myelodysplastic syndrome/acute myeloid leukaemia. These data provide important information regarding the long-term toxicity of bendamustine in previously treated patients. A small but meaningful number of patients achieved durable remissions following bendamustine. These rigorously collected, patient-level, long-term follow-up data provide reassurance that bendamustine or bendamustine plus rituximab is associated with efficacy and safety for patients with relapsed or refractory indolent non-Hodgkin lymphoma.

A unique CD4+ large granular lymphocytosis occurring in patients treated with tumor necrosis factor α inhibitors: report of 2 cases.

We report 2 cases of CD4(+) large granular lymphocyte (LGL) lymphocytosis occurring in patients being treated with a monoclonal antibody against tumor necrosis factor α for underlying autoimmune disorders. CD4(+) LGL lymphocytosis is a rare subset of LGL disease that has previously only been described in patients without underlying autoimmune disorders, and most demonstrate uniform coexpression of CD56 on the atypical T cells. The clinical features, with both cases occurring in patients with autoimmune disease, and immunophenotypic features, with both cases showing dim CD8 coexpression without CD56 in the CD4(+) LGLs, suggest that the reported cases are distinct from those previously described and may represent a novel T-cell LGL lymphocytosis emerging from iatrogenic immune modulation of patients with underlying autoimmune disorders.

Immunohistochemical evaluation of MYC expression in mantle cell lymphoma.

AIM: To assess the validity and potential clinical utility of evaluating MYC expression by immunohistochemistry (IHC) in mantle cell lymphoma (MCL). METHODS AND RESULTS: MYC IHC was scored on a tissue microarray containing 62 MCLs and 29 controls by two pathologists. Inter-observer correlation was high (intra-class correlation of 0.98). MYC IHC scores correlated with MYC expression (Spearman's rank correlation 0.69, P < 0.0001) and weakly with Ki67 proliferation index (Spearman's rank correlation 0.30, P = 0.03). Six blastic MCLs did not have higher mean MYC IHC scores or MYC mRNA expression than non-blastic MCLs. None of 57 cases assessed, including all of the blastic cases, showed MYC rearrangement by fluorescence in-situ hybridization. Multivariate analysis with backward selection from potential predictors including age, lactate dehydrogenase, leukocyte count, MIPI score, ECOG performance status, blastic morphology and Ki67 index showed that MYC IHC score is an independent predictor of progression-free survival (hazard ratio 2.34, 95% CI 1.42-3.88, P = 0.0009) and overall survival (hazard ratio 1.90, 95% CI 1.05-3.43, P = 0.034). CONCLUSIONS: We show that a new monoclonal anti-MYC antibody can enable accurate and reproducible visual assessment of MYC expression that is independently predictive of clinical outcomes in MCL.