High dose cytarabine with rituximab is not enough in first-line treatment of mantle cell lymphoma with high proliferation: early closure of the Nordic Lymphoma Group Mantle Cell Lymphoma 5 trial

The addition of bortezomib to rituximab, high-dose cytarabine and dexamethasone in relapsed or refractory mantle cell lymphoma-a randomized, open-label phase III trial of the European mantle cell lymphoma network

The therapy of relapsed or refractory (r/r) mantle cell lymphoma (MCL) patients remains a major clinical challenge to date. We conducted a randomized, open-label, parallel-group phase-III trial hypothesizing superior efficacy of rituximab, high-dose cytarabine and dexamethasone with bortezomib (R-HAD + B) versus without (R-HAD) in r/r MCL ineligible for or relapsed after autologous stem cell transplant (ASCT). Primary endpoint was time to treatment failure (TTF), secondary endpoints included response rates, progression free survival, overall survival, and safety. In total, 128 of 175 planned patients were randomized to R-HAD + B (n = 64) or R-HAD (n = 64). Median TTF was 12 vs. 2.6 months (p = 0.045, MIPI-adjusted HR 0.69; 95%CI 0.47-1.02). Overall and complete response rates were 63 vs. 45% (p = 0.049) and 42 vs. 19% (p = 0.0062). A significant treatment effect was seen in the subgroup of patients >65 years (aHR 0.48, 0.29-0.79) and without previous ASCT (aHR 0.52, 0.28-0.96). Toxicity was mostly hematological and attributable to the chemotherapeutic backbone. Grade ≥3 leukocytopenia and lymphocytopenia were more common in R-HAD + B without differences in severe infections between both arms. Bortezomib in combination with chemotherapy can be effective in r/r MCL and should be evaluated further as a therapeutic option, especially if therapy with BTK inhibitors is not an option. Trial registration: NCT01449344.

How I manage mantle cell lymphoma: indolent versus aggressive disease

Mantle cell lymphoma (MCL) is a mature B-cell lymphoma with a variable clinical course and historically poor prognosis. Management is challenging in part due to the heterogeneity of the disease course, with indolent and aggressive subtypes now well recognised. Indolent MCL is often characterised by a leukaemic presentation, SOX11 negativity and low proliferation index (Ki-67). Aggressive MCL is characterised by rapid onset widespread lymphadenopathy, extra-nodal involvement, blastoid or pleomorphic histology and high Ki-67. Tumour protein p53 (TP53) aberrations in aggressive MCL are recognised with clear negative impact on survival. Until recently, trials have not addressed these specific subtypes separately. With the increasing availability of targeted novel agents and cellular therapies, the treatment landscape is constantly evolving. In this review, we describe the clinical presentation, biological factors, and specific management considerations of both indolent and aggressive MCL and discuss current and potential future evidence which may help move to a more personalised approach.

Clinical and biological impact of SAMHD1 expression in mantle cell lymphoma

SAMHD1 is a deoxynucleoside triphosphate triphosphohydrolase (dNTPase) that restricts viral replication in infected cells and limits the sensitivity to cytarabine by hydrolysing its active metabolite, as recently shown in acute myeloid leukemia. Cytarabine is an essential component in the Nordic mantle cell lymphoma protocols (MCL2 and MCL3) for induction and high-dose chemotherapy treatment before autologous stem cell transplantation for younger patients with mantle cell lymphoma (MCL). We here investigated the expression of SAMHD1 in a population-based cohort of MCL (N = 150). SAMHD1 was highly variably expressed in MCL (range, 0.4% to 100% of positive tumor cells). Cases with blastoid/pleomorphic morphology had higher SAMHD1 expression (P = 0.028) and SAMHD1 was also correlated to tumor cell proliferation (P = 0.016). SAMHD1 expression showed moderate correlation to the expression of the transcriptional regulator SOX11 (P = 0.036) but genetic silencing of SOX11 and SAMHD1 by siRNA in MCL cell lines did not suggest mutual regulation. We hypothesized that expression of SAMHD1 could predict short time to progression in patients treated with Cytarabine as part of high-dose chemotherapy. Despite the correlation with known biological adverse prognostic factors, neither low or high SAMHD1 expression correlated to PFS or OS in patients treated according to the Nordic MCL2 or MCL3 protocols (N = 158).

Oxaliplatin before autologous transplantation in combination with high-dose cytarabine and rituximab provides longer disease control than cisplatin or carboplatin in patients with mantle-cell lymphoma: results from the LyMA prospective trial

LyMA trial has demonstrated the benefit of rituximab maintenance after autologous stem cell transplantation (ASCT) in previously untreated mantle-cell lymphoma patients (MCL). Induction consisted of four courses of R-DHAP (rituximab, dexamethasone, high-dose cytarabine, and platinum derivative). The platinum derivative (PD) choice was free: R-DHA-cisplatin, R-DHA-carboplatin, or R-DHA-oxaliplatin. We investigated the prognostic impact of each PD. PFS and OS calculated from inclusion and investigated in an intention-to-treat (ITT) (= 298) and per-protocol analyses (PP) (n = 227). R-DHACis, R-DHACa, or R-DHAOx were used at first cycle in 184, 76, and 38 patients, respectively. Overall, 71 patients (59 in the R-DHACis) required a change in PD, mainly because of PD toxicity. In ITT-analysis, PFS in the R-DHACis and R-DHACa groups were similar (4-year PFS of 65%), while R-DHAOx had a better PFS (4-year PFS of 65% versus 86.5%, respectively, HR = 0.44, p = 0.02). The 4-year OS was 92% for R-DHAOx versus 75.9% for R-DHACis/DHACa (HR = 0.37, p = 0.03). Similar results were yielded in the PP analysis. Low MIPI and R-DHAOx were independent favorable prognostic markers for both PFS (HR = 0.44, p = 0.035) and OS (HR = 0.36, p = 0.045). In vitro and in silico analyses confirmed that oxaliplatin has an anti-MCL cytotoxic effect that differs from that of other PD. R-DHAOx before ASCT provides better outcome in transplantation eligible young MCL patients.

Cytarabine nanotherapeutics with increased stability and enhanced lymphoma uptake for tailored highly effective therapy of mantle cell lymphoma

Mantle cell lymphoma (MCL) is a rare subtype of B-cell non-Hodgkin lymphoma (B-NHL) with chronically relapsing clinical course. Implementation of cytarabine (araC) into induction and salvage regimen became standard of care for majority of MCL patients. In this study, tailored N-(2-hydroxypropyl)methacrylamide (HPMA)-based polymer nanotherapeutics containing covalently bound araC (araC co-polymers) were designed, synthesized and evaluated for their anti-lymphoma efficacy in vivo using a panel of six patient-derived lymphoma xenografts (PDX) derived from newly diagnosed and relapsed / refractory (R/R) MCL. While free araC led to temporary inhibition of growth of MCL tumors, araC co-polymers induced long-term disappearance of the engrafted lymphomas with no observed toxicity even in the case of PDX models derived from patients, who relapsed after high-dose araC-based treatments. The results provide sound preclinical rationale for the use of HPMA-based araC co-polymers in induction, salvage or palliative therapy of MCL patients.

Front-line management of indolent non-Hodgkin lymphoma in Australia. Part 2: mantle cell lymphoma and marginal zone lymphoma

Mantle cell lymphoma (MCL) and the marginal zone lymphoma (MZL) subtypes (nodal MZL, extra-nodal MZL of mucosa-associated lymphoid tissue (MALT lymphoma) and splenic MZL) are uncommon lymphoma subtypes, accounting for less than 5-10% of all non-Hodgkin lymphoma. The evidence base for therapy is therefore limited and enrolment into clinical trials is preferred. Outcomes for patients with MCL have been steadily improving mainly due to the adoption of more intense strategies in younger patients, the use of rituximab maintenance and the recent introduction of bendamustine in older patients. MZL is a more heterogeneous group of cancer with both nodal, extra-nodal and splenic subtypes. Extranodal MZL may be associated with autoimmune or infectious aetiologies, and can respond to eradication of the causative pathogen. Proton pump inhibitor plus dual antibiotics in Helicobacter pylori positive gastric MALT lymphoma is curative in many patients. Watchful waiting is appropriate in most patients with asymptomatic advanced stage disease, which tends to behave in a particularly indolent manner. Other options for symptomatic disease include splenectomy, chemoimmunotherapy with rituximab and, more recently, targeted therapies.

Blastoid and pleomorphic mantle cell lymphoma: still a diagnostic and therapeutic challenge!

Blastoid mantle cell lymphoma is characterized by highly aggressive features and a dismal clinical course. These blastoid and pleomorphic variants are defined by cytomorphological features, but the criteria are somewhat subjective. The diagnosis may be supported by a high cell proliferation based on the Ki-67 labeling index. Recent analyses have shown that the Ki-67 index overrules the prognostic information derived from the cytology subtypes. Nevertheless, genetic analysis suggests that blastoid and pleomorphic variants are distinct from classical mantle cell lymphoma. In clinical cohorts, the frequency of these subsets varies widely but probably represents ∼10% of all cases. Chemotherapy regimens commonly used in mantle cell lymphoma, such as bendamustine, rarely achieve prolonged remissions when given at the dosage developed for classical variants of the disease. Thus, high-dose cytarabine–containing regimens with high-dose consolidation may be generally recommended based on the more aggressive clinical course in these patients. However, even with these intensified regimens, the long-term outcome seems to be impaired. Thus, especially in this patient subset, allogeneic transplantation may be discussed at an early time point in disease management. Accordingly, targeted approaches are warranted in these patients, but clinical data are scarce. Ibrutinib treatment results in high rates of responses, but the median duration of remission is <6 months. Similarly, lenalidomide and temsirolimus result in only short-term remissions. Novel approaches, such as chimeric antigenic receptor T cells, may have the potential to finally improve the dismal long-term outcome of these patients.

Update on mantle cell lymphoma

Mantle cell lymphoma (MCL) is a rare subtype of non-Hodgkin lymphoma that is most commonly treated with combination chemo-immunotherapy at diagnosis because of the poor prognosis. More indolent presentations have been described including patients who can defer initial therapy without adverse impact on survival. The 2016 World Health Organization updated classification describes 2 major subtypes, classical and leukemic nonnodal MCL, each with unique molecular features and clinical presentations. Although there is no standard of care for MCL, aggressive chemo-immunotherapy regimens containing rituximab and cytarabine, followed by consolidation with autologous stem cell transplantation and maintenance rituximab, are the most used approach in young fit patients, and chemo-immunotherapy, followed by rituximab maintenance, is most commonly used in older patients. Despite the improvement in response durations with currently available therapies, patients will inevitably relapse. A number of targeted therapies are approved in the relapsed setting and are now under evaluation in combination with standard frontline therapy. Although the approval of ibrutinib changed the landscape of therapy for relapsed MCL, prognosis remains poor after progression on ibrutinib supporting the development of ibrutinib combinations to prolong response duration as well as the development of other novel agents for ibrutinib refractory disease. With ibrutinib being incorporated into initial therapy regimens, new options will be needed at relapse. Prognostic markers, such as minimal residual disease, have been shown to correlate independently with outcomes along with predicting relapse, with the potential to guide therapeutic decisions. The future treatment of MCL therapy will need to incorporate therapy based on risk-stratification and nonchemotherapeutic approaches.

Efficacy of Standard Dose R-CHOP Alternating With R-HDAC Followed by Autologous Hematopoietic Cell Transplantation as Initial Therapy of Mantle Cell Lymphoma, a Single-Institution Experience

BACKGROUND

Young fit patients with mantle cell lymphoma (MCL) are commonly treated with induction chemotherapy followed by high-dose chemotherapy and autologous hematopoietic cell transplantation (AHCT). Induction regimens with modifications of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) and/or incorporation of high-dose cytarabine (HDAC) appear more effective than R-CHOP alone.

PATIENTS AND METHODS

We adopted a modification of the Nordic protocol using standard, rather than higher dose R-CHOP, alternating with HDAC (rituximab plus HDAC), for 3 cycles each or, for patients already treated with R-CHOP alone before referral for AHCT, an additional 2 cycles of rituximab plus HDAC. We herein report our experience with 28 patients treated with this regimen who proceeded to AHCT, and compare their outcomes with patients treated with either standard-dose R-CHOP (n = 38) or R-HCVAD/MA (cyclophosphamide, vincristine, doxorubicin, dexamethasone alternating with methotrexate, and cytarabine; n = 21), before AHCT.

RESULTS

With a median follow-up duration of 26 months, our data show that this modification of the Nordic regimen is a highly effective pre-AHCT first-line therapy for MCL (3-year progression-free and overall survival rates of 69% and 75%, respectively).

CONCLUSION

By using a less intense induction, this regimen can serve as a platform for combined use of novel agents, with less risk of additive toxicity.

Mantle Cell Lymphoma: Is It Time for a New Treatment Paradigm?

Mantle cell lymphoma is a relatively rare subtype of lymphoma with a great deal of heterogeneity, both clinically and biologically. Since its recognition as a separate entity in the early 1990s though, consistent efforts have led to a significant improvement of overall survival, from a median overall survival of 2.5 years initially to 5-7 years currently. This decades-long and stepwise progress, summarized in the article, definitely accelerated recently, shedding light on a changing paradigm.

The role of targeted treatment in mantle cell lymphoma: is transplant dead or alive?

Based on the profound biological insights of the last years into the molecular pathogenesis of mantle cell lymphoma and the clinical introduction of new targeted drugs, with high efficacy and a good safety profile, the therapeutic scenario for this tumor has been shown to be thoroughly favourable. No longer characterized by a uniformly dismal prognosis, mantle cell lymphoma has been revealed as a spectrum of different diseases, ranging from very indolent cases to highly aggressive and refractory ones. Thus, there is an urgent need to adapt therapy to accommodate the diverse presentations of the disease. High-dose chemotherapy, followed by autologous stem cell transplantation is the current standard of care for younger patients, generally providing high responses and long survival rates, but hampered by acute and long-term toxicity. In addition, some patients may be overtreated, while others could benefit from targeted approaches, based on the new, molecular-directed compounds. Such a personalized treatment based on the specific characteristics of individual patients may be guided by validated prognostic tools, such as the Mantle Cell Lymphoma International Prognostic Index and the Ki-67 Proliferative Index, as well as by early predictors of treatment response, like minimal residual disease analysis. Moreover, mutation screening of distinctive genomic alterations may provide new, predictive biomarkers, with an additional impact on clinical practice. Only after tailoring treatment according to the clinical and biological heterogeneity of the disease the role of transplantation and modern therapeutic options will be redefined in mantle cell lymphoma.

New paradigms in mantle cell lymphoma: is it time to risk-stratify treatment based on the proliferative signature?

The elucidation of crucial biologic pathways of cell survival and proliferation has led to the development of highly effective drugs, some of which have markedly improved mantle cell lymphoma (MCL) therapeutic opportunities in the past 10 years. Moreover, an undeniable clinical heterogeneity in treatment response and disease behavior has become apparent in this neoplasm. Thus, the need for biologic markers stratifying patients with MCL in risk classes deserving different treatment approaches has recently been fervently expressed. Among several newly discovered biomarkers, the dismal predictive value of a high proliferative signature has been broadly recognized in large studies of patients with MCL. Different techniques have been used to assess tumor cell proliferation, including mitotic index, immunostaining with Ki-67 antibody, and gene expression profiling. Ki-67 proliferative index, in particular, has been extensively investigated, and its negative impact on relapse incidence and overall survival has been validated in large prospective clinical trials. However, one important pitfall limiting its widespread use in clinical practice is the reported interobserver variability, due to the previous lack of a standardized approach for quantification among different laboratories. In the present review, we describe some of the major techniques to assess cell proliferation in MCL, focusing in particular on the Ki-67 index and its need for a standardized approach to be used in multicenter clinical trials. The value of MCL biologic prognostic scores (as MIPI-b) is discussed, along with our proposal on how to integrate these scores in the planning of future trials investigating a tailored therapeutic approach for patients with MCL. See all articles in this CCR Focus section, "Paradigm Shifts in Lymphoma."