Efficacy of bendamustine and rituximab in splenic marginal zone lymphoma: results from the phase II BRISMA/IELSG36 study

Marginal zone lymphoma international prognostic index: a unifying prognostic index for marginal zone lymphomas requiring systemic treatment

Background

Marginal zone lymphomas (MZL), comprised of three unique but related subtypes, lack a unifying prognostic score applicable to all the patients in need for systemic chemotherapy and/or immunotherapy.

Methods

Patients from the prospective NF10 study (NCT02904577) with newly diagnosed MZL and receiving frontline systemic therapy at diagnosis or after observation were used to train a prognostic model. The primary endpoint was progression-free survival (PFS) from start of treatment. The model was externally validated in a pooled analysis of two independent cohorts from the University of Iowa and Mayo Clinic Molecular Epidemiology Resource and the University of Miami.

Findings

We identified 501 eligible patients. After multivariable modeling, lactate dehydrogenase (LDH) above upper normal limit, hemoglobin <12 g/dL, absolute lymphocyte count <1 × 109/L, platelets <100 × 109/L, and MZL subtype (nodal or disseminated) were independently associated with inferior PFS. The proposed MZL International Prognostic index (MZL-IPI) combined these 5 factors, and we defined low (LRG, 0 factors, 27%), intermediate (IRG, 1-2 factors, 57%) and high (HRG, 3+ factors, 16%) risk groups with 5-y PFS of 85%, 66%, and 37%, respectively (c-Harrell = 0.64). Compared to the LRG, the IRG (Hazard Ratio [HR] = 2.30, 95% CI 1.39-3.80) and HRG (HR = 5.41, 95% CI 3.12-9.38) had inferior PFS. Applying the MZL-IPI to the pooled US cohort (N = 353), 94 (27%), 192 (54%), and 67 (19%) patients were classified as LRG, IRG, and HRG, respectively, and the model was validated for PFS (log-rank test p = 0.0018; c-Harrell = 0.578, 95% CI 0.54-0.62). The MZL-IPI was also prognostic for OS in both the training and the external validation sets.

Interpretation

MZL-IPI is a new prognostic score for use in all patients with MZL considered for systemic treatment.

Funding

The MER was supported by P50 CA97274 and U01 CA195568.

Spleen-targeted delivery systems and strategies for spleen-related diseases

The spleen, body's largest secondary lymphoid organ, is also a vital hematopoietic and immunological organ. It is regarded as one of the most significant organs in humans. As more researchers recognize the functions of the spleen, clinical methods for treating splenic diseases and spleen-targeted drug delivery systems to improve the efficacy of spleen-related therapies have gradually developed. Many modification strategies (size, charge, ligand, protein corona) and hitchhiking strategies (erythrocytes, neutrophils) of nanoparticles (NPs) have shown a significant increase in spleen targeting efficiency. However, most of the targeted drug therapy strategies for the spleen are to enhance or inhibit the immune function of the spleen to achieve therapeutic effects, and there are few studies on spleen-related diseases. In this review, we not only provide a detailed summary of the design rules for spleen-targeted drug delivery systems in recent years, but also introduce common spleen diseases (splenic tumors, splenic injuries, and splenomegaly) with the hopes of generating more ideas for future spleen research.

Marginal zone lymphoma: 2023 update on diagnosis and management

DISEASE OVERVIEW

Marginal zone lymphomas (MZL) are collectively the second most common type of indolent lymphoma.

DIAGNOSIS

Three subtypes of MZL are recognized: splenic, extranodal, and nodal. The diagnosis is secured following biopsy of an involved nodal or extranodal site demonstrating a clonal B-cell infiltrate with CD5 and CD10 negative immunophenotype most common. Some cases will features IgM paraprotein, but MYD88 L256P mutations are less frequent than in Waldenstrom macroglobulinemia. Prognostication Several prognostic models have been developed, including the MALT-IPI and the MZL-IPI. The latter is broadly applicable across MZL subtypes and incorporates elevated serum LDH, anemia, lymphopenia, thrombocytopenia and nodal or disseminated subtypes as independent predictors of outcome.

TREATMENT

We discuss suggested approach to therapy for both early and advanced-stage disease, with reference to chemo-immunotherapy, radiotherapy, and emerging treatments in relapsed/refractory disease such as BTK inhibitors.

Splenic marginal zone lymphoma in Sweden 2000-2020: Increasing rituximab use and better survival in the elderly

The treatment of splenic marginal zone lymphoma is debated: splenectomy (the old standard-of-care) is better than chemotherapy but maybe not better than rituximab-containing treatment. We examined all 358 patients diagnosed with splenic marginal zone lymphoma in Sweden 2000-2020. The median overall survival was 11.0 years. The median age was 73 years; 61% were women. Age was the only independently prognostic clinical characteristic. Eighty-six patients were started on wait-and-watch, 90 rituximab monotherapy, 47 rituximab-chemotherapy, 88 splenectomy, 37 chemotherapy, and 10 both systemic therapy and splenectomy. Overall survival was inferior in patients treated with chemotherapy, but equal in patients treated with rituximab, rituximab-chemotherapy and splenectomy. Patients treated with both systemic therapy and splenectomy showed good outcome, suggesting that surgery can be safely reserved for nonresponders. After adjustment for age, survival did not differ between patients started on wait-and-watch and those treated with splenectomy or rituximab-containing therapy. Over time, rituximab use and survival increased in patients ≥73 years. This is, to our knowledge, the largest population-based study of splenic marginal zone lymphoma patients treated with upfront rituximab. We conclude that wait-and-watch remains the most reasonable option in asymptomatic splenic marginal zone lymphoma patients. Symptomatic patients should be offered single-agent rituximab in first line.

Low-risk HPLLs/ABC score patients with splenic marginal zone lymphoma can be safely managed without treatment: Results from a prospective Spanish study

The aims of our study were to analyse compliance with the 2014 GELTAMO SMZL Guidelines, in patients with splenic marginal zone lymphoma (SMZL), and to evaluate the outcome according to the HPLLs/ABC-adapted therapeutic strategy. Observational prospective multicenter study of 181 SMZL patients diagnosed between 2014 and 2020. Lymphoma-specific survival (LSS), composite event-free survival (CEFS) and response rates were assessed. 57% of the 168 patients included in the analysis followed the Guidelines. The overall response rate was higher in the rituximab chemotherapy and in the rituximab arms compared with the splenectomy arm (p < 0.001). The 5-year overall survival was 77% and the 5-year LSS of 93%. There were no differences in the 5-year LSS according to the treatment received (p = 0.68). The 5-year CEFS in the overall series was 45%, and there were significant differences between scores A and B (p = 0.036). There were no significant differences when comparing LSS and progression-free survival in patients treated with rituximab or rituximab chemotherapy at diagnosis or after observation. Our data support HPLLs/ABC score as a practical tool for the management of SMZL, observation as the best approach for patients in group A and rituximab as the best treatment for group B.

Marginal zone lymphomas

The three main types of marginal zone lymphoma (MZL), recognized by the current lymphoma classifications are the extranodal MZL of mucosa-associated lymphoid tissue, the splenic MZL, and the nodal MZL. They share some karyotype lesions (trisomies of chromosomes 3 and 18, deletions at 6q23), and alterations of the nuclear factor kappa B (NFkB) pathway are also common in all of them. However, they differ in the presence of recurrent translocations, mutations affecting the Notch signaling pathway (NOTCH2 and less commonly NOTCH1), the transcription factors Kruppel-like factor 2 (KLF2) or the receptor-type protein tyrosine phosphatase delta (PTPRD). This review summarizes the most recent and significant advances in our understanding of the epidemiology, genetics, and biology of MZLs and outlines the current principles of the standard management of MZL at different anatomic sites.

The role of splenectomy in management of splenic B-cell lymphomas

INTRODUCTION

Splenic B-cell lymphomas are rare and understudied entities. Splenectomy is frequently required for specific pathological diagnosis in patients with splenic B-cell lymphomas other than classical hairy cell leukemia (cHCL), and can be effective and durable therapy. Our study investigated the diagnostic and therapeutic role of splenectomy for non-cHCL indolent splenic B-cell lymphomas.

METHODS

Observational study of patients with non-cHCL splenic B-cell lymphoma undergoing splenectomy between 1 August 2011 and 1 August 2021 at the University of Rochester Medical Center. The comparison cohort was patients categorized as having non-cHCL splenic B-cell lymphoma who did not undergo splenectomy.

RESULTS

Forty-nine patients (median age 68 years) had splenectomy (SMZL n = 33, HCLv n = 9, SDRPL n = 7) with median follow up of 3.9 years post splenectomy. One patient had fatal post-operative complications. Post-operative hospitalization was ≤ 4 days for 61% and ≤ 10 days for 94% of patients. Splenectomy was initial therapy for 30 patients. Of the 19 patients who had previous medical therapy, splenectomy changed their lymphoma diagnosis in 5 (26%). Twenty-one patients without splenectomy were clinically categorized as having non-cHCL splenic B-cell lymphoma. Nine required medical treatment for progressive lymphoma and of these 3 (33%) required re-treatment for lymphoma progression compared to 16% of patients following first line splenectomy.

CONCLUSION

Splenectomy is useful for the diagnosis of non-cHCL splenic B-cell lymphomas with comparable risk/benefit profile and remission duration to medical therapy. Patients with suspected non-cHCL splenic lymphomas should be considered for referral to a high-volume center with experience in performing splenectomies for definitive diagnosis and treatment.

Management of Marginal Zone Lymphoma: A Canadian Perspective

Marginal zone lymphomas (MZL) are a rare, heterogenous group of lymphomas, accounting for 5-17% of indolent non-Hodgkin lymphomas in the western world. They can be further divided into three subtypes: extranodal MZL, splenic MZL, and nodal MZL. These subtypes differ in clinical presentation and behavior, which influences how they are managed. There is currently no standard of care for the treatment of MZL, owing to the difficulty in conducting phase 3 randomized trials in MZL, and the fact that there are limited data on the efficacy of therapy in individual subtypes. Treatment practices are thus largely borrowed from other indolent lymphomas and are based on patient and disease characteristics, as well as access to therapy. This review summarizes the Canadian treatment landscape for MZL and how these therapies may be sequenced in practice.

Incidental Splenic Marginal Zone Lymphoma With Extreme Macrocytosis After Hydroxyurea Use: A Case Report

Splenic marginal zone lymphoma (SMZL) is a low-grade mature B-cell lymphoma that typically presents in the form of splenomegaly and lymphocytosis. The diagnosis is traditionally made through splenic histology, the presence of circulating villous lymphocytes, or bone marrow biopsy. Its treatment can be in the form of chemotherapy, such as rituximab, or active surveillance. This case presentation discusses a 76-year-old female with a long history of hydroxyurea use for an unknown reason presenting with atypical symptoms requiring bone marrow biopsy to diagnose SMZL. This unique case demonstrates the importance of further research and studies into atypical SMZL presentations and hydroxyurea's potential in precipitating secondary malignancies.

Management of marginal zone lymphomas

Marginal zone lymphomas (MZLs) represent about 7% of B-cell non-Hodgkin lymphomas and include 3 different subtypes-namely, extranodal (EMZL), nodal, and splenic (SMZL). The initial assessment requires specific diagnostic and staging procedures depending on organ-related peculiarities. In particular, although positron emission tomography/computed tomography was not initially recommended, recent data have reassessed its role in the routine staging of MZL, especially when only localized treatment is planned or there is a suspicion of histologic transformation. Recent findings have improved the risk stratification of MZL patients, highlighting the association of early progression after frontline therapy with worse overall survival. A significant fraction of MZL cases may be related to specific bacterial (ie, Helicobacter pylori in gastric EMZL) or viral infections (hepatis C virus), and in the earlier phases of disease, a variable percentage of patients may respond to anti-infective therapy. Involved-site radiotherapy has a central role in the management of localized EMZL not amenable to or not responding to anti-infective therapy. Although rituximab-based treatments (bendamustine- rituximab in advanced EMZL or rituximab monotherapy in SMZL) have demonstrated favorable results, the current therapeutic scenario is predicted to rapidly change as emerging novel agents, especially Bruton's tyrosine kinase inhibitors, have demonstrated promising efficacy and safety profiles, leading to their approval in the relapsed setting. Moreover, a large variety of novel agents (phosphatidylinositol 3-kinase inhibitors, chimeric antigen receptor T-cells, bispecific antibodies) are being tested in MZL patients with encouraging preliminary results.

[Splenic lymphoma, diagnosis and treatment]

Some common clinical situations, such as splenomegaly or lymphocytosis, or less common, such as autoimmune hemolytic anemia, cold agglutinin disease, or cryoglobulinemia can lead to the diagnosis of splenic lymphoma. Splenic lymphoma is rare, mainly of non-hodgkinian origin, encompassing very different hematological entities in their clinical and biological presentation from an aggressive form such as hepato-splenic lymphoma to indolent B-cell lymphoma not requiring treatment such as marginal zone lymphoma, the most frequent form of splenic lymphoma. These entities can be challenging to diagnose and differentiate. This review presents different clinical and biological manifestations suspicious of splenic lymphoma and proposes a diagnosis work-up. We extended the strict definition of splenic lymphoma (lymphoma exclusively involving the spleen) to lymphoma thant can be revealed by a splenomegaly and we discuss the differential diagnosis of splenomegaly.

Refractory Splenic Marginal Zone Lymphoma Responsive to Combination Venetoclax and Bortezomib (Velcade) (V2) Therapy

Standard treatment regimens for the management of patients with refractory splenic marginal zone lymphoma (SMZL) are currently unavailable. Here, we report a case of SMZL, which, after failing multiple therapeutics, demonstrated an impressive clinical response to combined Venetoclax and Velcade (V²), a treatment combination currently being investigated in the setting of refractory multiple myeloma. We also report a unique histopathology and mutational profile that may have important implications for the characterization and prognosis of SMZL.

Immunotherapy in indolent Non-Hodgkin's Lymphoma

Treatment of non-Hodgkin lymphoma (NHL) in general has improved over the years with the emergence of the monoclonal antibodies (MAB) therapy. NHL is divided into B cell NHL and T cell NHL. Treatment of NHL was based on the subtype of NHL and its staging. NHL is divided into aggressive and indolent NHL (iNHL). Subtypes of iNHL include: Follicular lymphoma (FL), Marginal zone lymphoma (MZL), Chronic lymphocytic leukemia/small-cell lymphocytic lymphoma (CLL/SLL), Gastric mucosa-associated lymphoid tissue (MALT) lymphoma, Lymphoplasmacytic lymphoma, Waldenström macroglobulinemia, Nodal marginal zone lymphoma (NMZL), Splenic marginal zone lymphoma (SMZL). Chemotherapy was the main stay treatment of iNHL until the emergence of Rituximab, anti-CD20 MAB targeting CD-20 surface cell antigens that are present on B-cells lymphoma and not on precursor cells, mainly efficacious in B cell iNHL, It became the mainstay treatment in follicular lymphoma (FL) as a single agent modality or in combination with chemotherapy. The anti-CD20 Rituximab played an important role in the development of the treatment of iNHL to become FDA approved in 1997. It was also proven effective in multiple other types of lymphoma. MAB through targeting the cell surface antigen leads to a direct or immune mediated cytotoxicity. This carries few side effects, including allergic reactions. Other than that, a resistance mechanism to rituximab emerged by inducing a failure in the apoptosis mechanism. Alternative mechanisms of resistance included the presence of soluble antigens that could act by binding to the antibody present before the drug itself can bind the lymphoma cell. Thus, the interest in immunotherapy grew further to explore the possibility of conjugating an immune mediated drug to a radio-sensitizing agent in order to enhance the selectivity of the drug. Here came the development of 90Y-ibritumomab tiuxetan and 131I-tositumomab. After it, humanized anti-CD20 emerged ofatumumab, IMMU106 (veltuzumab) in 2005, and ocrelizumab which are considered as second generation anti-CD20 and 3^rd generation anti-CD20 include AME-133v (ocaratuzumab), PRO131921 and GA101 (obinutuzumab). Also multiple other agents emerged targeting different surface cell antigens like CD52 (alemtuzumab), CD22 (unconjugated epratuzumab and calicheamicin conjugated CMC-544 [inotuzumab ozogamicin]), CD80 (galiximab), CD2 (MEDI-507 [siplizumab]), CD30 (SGN-30 and MDX-060 [iratumumab], Brentuximab vedotin), CD40 (SGN-40), and CD79b (Polatuzumab). Other agents include MAB targeting T-Cells like mogamulizumab, Denileukin Diftitox and BiTEs or bispecific T cell engagers like Mosunetuzumab, Glofitamab, and Epcoritamab. Moreover, further studies came up to evaluate the role of immunotherapy in combination chemotherapy as a pathway to evade the resistance mechanisms. Side effects of the treatment were mainly infusion related adverse reactions, myelosuppression in conjugated forms leading to immunosuppression and subsequently to infectious complications. Another important aspect in immunotherapy is the half-lives of the medication which is an important factor that can influence the evaluation of the response. The MAB treatment showed important benefit in the treatment of iNHL and it continuously shows how rapidly it can develop to provide optimum care and benefit to patients with iNHL.

Immunochemotherapy and Maintenance With Obinutuzumab or Rituximab in Patients With Previously Untreated Marginal Zone Lymphoma in the Randomized GALLIUM Trial

The aim of this study was to explore the efficacy and safety of obinutuzumab (G)- versus rituximab (R)-chemotherapy in a subgroup of patients with previously untreated marginal zone lymphoma (MZL) in the phase III GALLIUM trial (NCT01332968). Patients had stage III/IV (or stage II with bulky disease), splenic, nodal, or extranodal MZL requiring treatment. Patients were randomized 1:1 to receive G- or R-chemotherapy (cyclophosphamide, doxorubicin, vincristine, and prednisone; cyclophosphamide, vincristine, and prednisone; or bendamustine, allocated at patient level). Patients with complete/partial response at the end of induction (EOI) received G/R maintenance. Investigator-assessed progression-free survival (PFS), other time-to-event endpoints, response, and safety were assessed. Overall, 195 patients with MZL were included in this analysis: G-chemotherapy (n = 99), R-chemotherapy (n = 96). Median observation time: 59.3 months. No meaningful difference was observed between arms for PFS (4-y PFS rates: G-chemotherapy, 72.6%; R-chemotherapy, 64.1%), other time-to-event endpoints, or EOI response rates (by computed tomography [CT; G-chemotherapy, 81.8%; R-chemotherapy, 81.3%] and positron emission tomography CT [G-chemotherapy, 79.2%; R-chemotherapy, 87.5%]). All patients experienced ≥1 adverse event (AE). G-chemotherapy was associated with a higher incidence of grade 3–5 (86.1% versus 77.4%), grade 5 (14.9% versus 9.7%), and serious (66.3% versus 51.6%) AEs versus R-chemotherapy. Both arms had a higher incidence of grade 3–5 and serious AEs than patients with follicular lymphoma (GALLIUM), with G-chemotherapy being less tolerable than R-chemotherapy. Based on the observed tolerability of G-chemotherapy versus R-chemotherapy, and the comparable efficacy of G-chemotherapy and R-chemotherapy in this analysis, G-chemotherapy cannot be recommended as first-line treatment for MZL.

Risk-tailored treatment of splenic marginal zone lymphoma

Splenic marginal zone lymphoma (SMZL) is a rare lymphoproliferative disease involving B-cells and affecting elderly patients. SMZL plague peripheral blood and bone marrow, spleen. Lymph nodes are generally spared. SMZL is due to a protracted antigen stimulation of B lymphocytes and of microenvironment leading B-cell to polyclonal and then oligoclonal/monoclonal growth, promoting lymphoproliferation. Integration of the NOTCH2 and NFk-B signaling has been recently identified as the primary mechanism of neoplastic proliferation in SMZL. In total 20% of cases carry mutations in NOTCH2. Although SMZL has an indolent course, progression to diffuse large B-cell lymphoma occurs in about 10-15% of patients. Establishing the prognosis is a key step in disease management, depending on both individual risk and patients' health status. This review discusses tailored treatment of SMZL patients. Progression risk factors include nodal and extra-nodal involvement, peripheral lymphocytosis, anemia and thrombocytopenia. Patients with two or more score points have a median survival of <5 years. Watch and wait strategy is appropriate in low-risk and asymptomatic patients, whereas treatment of symptomatic patients ranges from splenectomy to rituximab monotherapy or associated with chemotherapy.

Role of antibody-based therapy in indolent non-Hodgkin's lymphoma

Monoclonal antibodies (mAb) for indolent non-Hodgkin's lymphoma (iNHL) including follicular and marginal zone lymphomas was a key therapeutic development that changed the natural history of these diseases. Rituximab, a chimeric anti-CD20 mAb, was the first immunotherapy ever used in cancer, and a current cornerstone of lymphoma therapies. Since, we saw development of humanized antibodies, next generations anti-CD20, mAbs targeting other markers on tumor cells (CD19 and CD22), its microenvironment (PD-1, CD47), antibody drug conjugates and bispecific T cell engagers. Given their activity, safety and specificity, mAbs are well poised to remain an essential therapeutic tool for iNHL and other malignancies.

CD5 expression in marginal zone lymphoma predicts differential response to rituximab or bendamustine/rituximab

We examined outcomes of 244 patients with marginal zone lymphoma (MZL) diagnosed in 2010-2020, of which 25 (10%) expressed CD5. CD5 expression was present in 22% of splenic, 8% of nodal, and 5% of extranodal MZL, and showed frequent blood/bone marrow involvement, elevated lactate dehydrogenase, and TP53 deletions. CD5 expression was not associated with progression-free or overall survival, but it conferred a significantly higher risk of histologic transformation (22% versus 4% at 5 years, p = 0.002). Among patients receiving first-line rituximab monotherapy, CD5 expression was associated with lower response rate (30% versus 77%, p = 0.006), PFS (25% versus 45% at 3 years, p = 0.003) and OS (44% versus 77%, p = 0.010), whereas CD5 status did not significantly affect outcomes of patients receiving bendamustine with rituximab (P for interaction = 0.012 for progression-free survival). CD5-positive MZL may have a propensity to leukemic dissemination, histologic transformation, and may derive benefit from first-line bendamustine/rituximab rather than rituximab alone.

Two rare cases of bronchus-associated lymphoid tissue lymphoma successfully treated with rituximab-bendamustine

BALT lymphoma is a rare B-NHL with a favorable prognosis. We here report on two patients with nonspecific symptoms: one showed as major symptom severe thrombocytopenia and the other dyspnea and dry cough, thereby suggesting an inflammatory focus in the lungs. There is no standard of care established yet. Both patients were successfully treated with rituximab and bendamustine. Thus, combined immunochemotherapy should be considered as first-line therapy as in other MALT lymphomas, if the treatment/eradication of an underlying chronic inflammatory disorder/trigger factor can be excluded.

Rare lymphomas in routine practice - Treatment and outcome in marginal zone lymphoma in the prospective German Tumour Registry Lymphatic Neoplasms

Owing to its heterogeneity and rarity, management of disseminated marginal zone B‐cell lymphoma (MZL) remains largely understudied. We present prospective data on choice of systemic treatment and survival of patients with MZL treated in German routine practice. Of 175 patients with MZL who had been documented in the prospective clinical cohort study Tumour Registry Lymphatic Neoplasms (NCT00889798) collecting data on systemic treatment, 58 were classified as extranodal MZL of mucosa‐associated lymphoid tissue (MALT) and 117 as non‐MALT MZL. We analyzed the most commonly used first‐line and second‐line chemo(immuno)therapies between 2009 and 2016 and examined objective response rate (ORR), progression‐free survival (PFS), overall survival (OS) and prognostic factors for survival. Compared to patients with MALT MZL, those with non‐MALT MZL more often presented with bone marrow involvement (43% vs. 14%), Ann Arbor stage III/IV (72% vs. 57%) and were slightly less often in good general condition (ECOG = 0; 41% vs. 47%). In German routine practice, rituximab‐bendamustine for a median of 6 cycles was the most frequently used first‐line (76%) and second‐line treatment (36%), with no major differences between MZL subtypes. The ORR for patients encompassing any positive response was 81%. For patients with MALT and non‐MALT MZL, respectively, 5‐years PFS was 69% (95% CI 52%–81%) and 66% (95% CI 56%–75%), 5‐years OS 79% (95% CI 65%–89%) and 75% (95% CI 66%–83%). Cox proportional hazards models showed a significantly increased risk of mortality for higher age in all patient groups. Our prospective real world data give valuable insights into the management and outcome of non‐selected patients with MZL requiring systemic treatment and can help optimize therapy recommendations.

How we treat mature B-cell neoplasms (indolent B-cell lymphomas)

Mature B cell neoplasms, previously indolent non-Hodgkin lymphomas (iNHLs), are a heterogeneous group of malignancies sharing similar disease courses and treatment paradigms. Most patients with iNHL have an excellent prognosis, and in many, treatment can be deferred for years. However, some patients will have an accelerated course and may experience transformation into aggressive lymphomas. In this review, we focus on management concepts shared across iNHLs, as well as histology-specific strategies. We address open questions in the field, including the influence of genomics and molecular pathway alterations on treatment decisions. In addition, we review the management of uncommon clinical entities including nodular lymphocyte-predominant Hodgkin lymphoma, hairy cell leukemia, splenic lymphoma and primary lymphoma of extranodal sites. Finally, we include a perspective on novel targeted therapies, antibodies, antibody-drug conjugates, bispecific T cell engagers and chimeric antigen receptor T cell therapy.

How do we sequence therapy for marginal zone lymphomas?

Marginal zone lymphomas are indolent diseases. Overall survival rates are very good, but patients tend to relapse and may do so several times. The concept of treatment sequencing is therefore important and necessary to preserve adequate organ function and to avoid excessive toxicity, with the final goal of achieving long survival times. Systemic treatments and chemotherapy are considered to be an option in multiply relapsing disease, in cases that are in an advanced stage at presentation or relapse, and in cases where initial local treatments lack efficacy. Targeted agents and new drugs can provide chemotherapy-free alternatives in heavily pretreated patients.

A phase II trial of bendamustine in combination with ofatumumab in patients with relapsed or refractory marginal zone B-cell lymphomas

Marginal zone lymphomas (MZLs) are indolent yet incurable lymphomas with frequent relapses following therapy. For patients with relapsed/refractory disease, no standard therapies exist. Here we report results of an exploratory phase II study aimed at assessing the efficacy and safety of the alkylator agent bendamustine in combination with the second-generation anti-CD20 monoclonal antibody, ofatumumab, in patients with relapsed or refractory MZL. Patients with MZL and previously treated with at least one line of systemic therapy were eligible. Treatment consisted in bendamustine (90 mg/m² on days 1 and 2) and ofatumumab (1000 mg on day 1) in 28-day cycles for up to six cycles. Sixteen patients were included in the trial. In one patient, the diagnosis was revised after two cycles of treatment and was excluded from the efficacy analysis. Among 15 patients with MZL, 14 were evaluable for response: the overall and complete response rates were 92.9% and 57.1%, respectively. The median duration of response was 30.4 months (95% confidence interval [CI], 15.5 -not estimable) and 2-years progression-free survival 77% (95% CI, 43%-92%). Fifteen patients (94%) experienced grade 3-4 adverse events. Toxicity was mostly hematological. Neutropenia grade ≥3 was recorded in 27% of patients, lymphocytopenia in 93%, and infections and febrile neutropenia each in 13%. One patient discontinued treatment due to myocardial infarction; no treatment-related deaths occurred. The combination of bendamustine with ofatumumab was active with an acceptable toxicity profile in this small phase II trial and can be considered for further investigation in relapsed/refractory MZL patients.

Rituximab Monotherapy or in Combination with Bendamustine Is Not Inferior to Rituximab-CHOP Regimen in the Treatment of Patients with Splenic Marginal Zone Lymphoma in the Real Life

Splenic marginal zone lymphoma (SMZL) is a rare lymphoma belonging to the marginal zone lymphoproliferative disorders. Usually, SMZL occurs with indolent presentation and, when required, the standard of care is represented by rituximab-based regimens. No direct comparison of different rituximab-based combinations and polychemotherapy regimens has been conducted to date. In a monocentric cohort of 68 SMLZ patients, we showed that rituximab in monotherapy or in combination with bendamustine, compared with rituximab associated with the polychemotherapy cycle cyclophosphamide, hydroxydaunorubicin, vincristine and prednisolone (CHOP), resulted in a higher 5-year progression-free survival (91.3 ± 9% and 75 ± 15.7% vs. 30.8 ± 12.1%, p < 0.001). Platelets at diagnosis <100 ×109/L (p = 0.034, HR = 4.3) and transformation into diffuse large B-cell lymphoma (p = 0.031, HR = 4.3) were associated with a lower overall survival.

Risk adapted approach: How to treat splenic marginal zone lymphoma in resource-poor settings? - The real-life experience of a Brazilian cancer treatment center

Background

Splenic marginal zone lymphoma (SMZL) is a rare lymphoid B-cell malignant neoplasm with primary involvement of the spleen. It is a chronic disease, of indolent behavior and prolonged survival. However, 25% of cases have higher biological aggressiveness, propensity for histological transformation to high grade B-cell non-Hodgkin lymphoma and shortened survival. Recognition of these cases of reserved outcome is important for selecting a risk-adapted therapeutic approach in a resource-poor settings.

Methods

We described clinical and epidemiological characteristics, survival analysis and prognostic factors in a retrospective cohort of 39 SMZL patients, treated in Latin America.

Results

We observed a predominance of female (71.8%), median age of 63 years and higher incidence of B symptoms (56.4%) and extra-splenic involvement (87.1%) than in European and North-American series. With a median follow-up of 8.7 years (0.6-20.2 years), estimated 5-year overall survival (OS) and progression-free survival (PFS) were 76.9% and 63.7%, respectively. Factors with adverse prognostic impact on OS and PFS were Hb < 100 g/L, platelet count < 100 x 10⁹/L, albumin < 3.5 g/dL, LDH > 480 U/L and high-risk Arcaini and SMZL/WG scores. Despite a relative low number of patients, no superiority was observed among the therapeutic regimens used including rituximab monotherapy, splenectomy and cytotoxic chemotherapy.

Conclusion

Therefore, in resource-poor settings, where access to immunotherapy is not universal for all SMZL patients, we suggest that first-line should consist on rituximab therapy for elderly patients or with high surgical risk or with at least 1 risk factor identified in our study. Remainders can be safely managed with splenectomy.

Bendamustine-rituximab regimen in untreated indolent marginal zone lymphoma: experience on 65 patients

First line therapy of patients with marginal zone lymphomas (MZL) is not well established and various regimens with chemo-immunotherapy can be used. Rituximab plus bendamustine (BR) is an effective and manageable treatment option for patients affected by indolent non-Hodgkin lymphoma. The aim of this monocentric retrospective study was to analyze the effectiveness and safety of the use of BR regimen in MZL patients in first line in daily clinical practice. The treatment schedule was rituximab at the dose of 375 mg/m² on day 1 of each cycle and bendamustine at the dose of 90 mg/m² on day 2 and 3, every 28 days for a maximum of 6 cycles. We analyzed 65 MZL patients (28 extranodal [EMZL], 23 splenic [SMZL], and 14 nodal [NMZL]) who underwent BR regimen as first line treatment. The median time from diagnosis to therapy was 2.5 months. Final responses were: 38 complete response (CR, 58.5%), 20 partial response and 7 progressive disease, leading to an overall response rate (ORR) of 89.2%. With respect to the histology, the ORR was 89.3% for EMZL, 82.6% for SMZL and 100% for NMZL, respectively (difference not statistically significant). With a median follow-up time of 44.6 months (range, 3.3-175.0 months), 2 (one EMZL after 42 months and one SMZL after 10 months) of 38 (5.2%) CR patients had disease relapse, yielding an estimated disease free survival of 89.2% at 61.1 months. The estimated 6-year progression free survival was 71.8% with 15 relapsed/progressed patients showing lymphoma recurrence within 48 months from end of treatment. The most frequently reported adverse events (any grade) were neutropenia (N = 35, 53.8%), fatigue (N = 15, 23.0%), and nausea (N = 12, 18.4%). All toxicities quickly resolved and no treatment-related death occurred. The BR regimen is effective and feasible in MZL patients inducing prolonged disease control with manageable toxicities.

Use of anti-CD20 therapy in follicular and marginal zone lymphoma: a review of the literature

The identification of the CD20 antigen in 1979 was the first step in what would become a therapeutic milestone opening the use of immunotherapy in hematological diseases. This protein is expressed on the surface of developing B cells, but not the early progenitors or mature plasma cells. In 1997, rituximab was approved by the Food and Drug Administration, and since then it has revolutionized the treatment of B-cell malignancies. It is used as a monotherapy and in combination, at induction, at relapsed, and also in maintenance. Indolent non-Hodgkin lymphomas are characterized by a long and non-aggressive course. In this group of lymphomas, rituximab represented a great therapeutic improvement, achieving lasting responses with few adverse effects. Nowadays, second-generation molecules are emerging that may have important advantages compared to rituximab, as well as biosimilars that represent an important cost-effective option.

Marginal Zone Lymphoma: State-of-the-Art Treatment

OPINION STATEMENT

Despite being the second most common indolent non-Hodgkin's lymphoma (iNHL), marginal zone lymphoma (MZL) remains largely understudied, and given its underlying disease heterogeneity, it is challenging to define a single treatment approach for these patients. For localized disease, local therapy is recommended such as triple therapy for H. pylori in gastric extranodal MZL, splenectomy for splenic MZL, and radiotherapy for nodal MZL. For disseminated disease with low tumor burden, a watch and wait or single-agent rituximab can be used. However, for symptomatic disease, a similar approach to follicular lymphoma (FL) can be used with chemoimmunotherapy approaches such as bendamustine and rituximab. High FDG uptake is not common in MZL and is not diagnostic by itself of transformation to high-grade lymphoma but informs the choice of the site to be biopsied. Transformation into a large B cell lymphoma is treated with R-CHOP-like regimens. Patients with relapsing disease after at least one CD20-based therapy have several recently approved chemotherapy-free options including B cell receptor inhibitors such ibrutinib (approved specifically in MZL) and immunomodulatory agents such as lenalidomide and rituximab (FDA approved in MZL and FL). Phosphoinositide 3-kinase (PI3K) inhibitors have shown excellent activity in iNHL, specifically in MZL, with breakthrough designation status for copanlisib and umbralisib, allowing off label use of this class of agents in clinical practice. With the availability of prospective clinical trials using chemo-free approaches, specifically those targeting abnormal signaling pathways activated in MZL tumors and its microenvironment, treating physicians are encouraged to enroll patients on these clinical trials in order to better understand the underlying biology, mechanisms of response, and resistance to current therapies and help design future rationale combination strategies.

Contemporary management of nodal and primary splenic marginal zone lymphoma

Introduction: Marginal zone lymphoma (MZL) accounts for approximately 10% of all cases of non-Hodgkin lymphoma and includes 3 clinically distinct subtypes: extranodal (MALT), splenic (SMZL), and nodal (NMZL). Though commonly grouped in trials of iNHL the clinical behavior, molecular features, and response to therapy of MZL is distinct from other iNHL subtypes and varies among MZL subtypes.Areas covered: This review focuses on the contemporary management of NMZL and SMZL. Treatment with monoclonal antibodies, chemoimmunotherapy, BTK inhibitors, PI3K/mTOR inhibitors, Bcl2 inhibitors, lenalidomide, and CAR-T cell therapy will be covered.Expert opinion: In the era of targeted medicine, the need to develop MZL specific clinicogenetic models with prognostic and predictive value in both the frontline and relapsed/refractory setting is becoming increasingly apparent. Due to the relative rarity of each MZL subtype, the use of novel trial design with correlative studies is imperative to advance the field.