Unmarried or less-educated patients with mantle cell lymphoma are less likely to undergo a transplant, leading to lower survival

Empowering macrophages: the cancer fighters within the tumour microenvironment in mantle cell lymphoma

In Mantle Cell Lymphoma (MCL), the role of macrophages within the tumour microenvironment (TME) has recently gained attention due to their impact on prognosis and response to therapy. Despite their low absolute number in MCL tumour tissue, recent findings reveal an association between the levels of macrophages and prognosis, consistent with trends observed in other lymphoma subtypes. M2-like macrophages, identified by markers such as CD163, contribute to angiogenesis and suppression of the immune response. Clinical trials with MCL patients treated with chemoimmunotherapy and targeted treatments underscore the adverse impact of high levels of M2-like macrophages. Immunomodulatory drugs like lenalidomide reduce the levels of MCL-associated CD163+ macrophages and enhance macrophage phagocytic activity. Similarly, clinical approaches targeting the CD47 "don't eat me" signalling, in combination with the anti-CD20-antibody rituximab, demonstrate increased macrophage activity and phagocytosis of MCL tumour cells. Cell-based therapies such as chimeric antigen receptor (CAR) T-cell have shown promise but various challenges persist, leading to a potential interest in CAR-macrophages (CAR-M). When macrophages are recruited to the TME, they offer advantages including phagocytic function and responsiveness to microenvironment alterations, suggesting their potential as a manipulable and inducible alternative when CAR T-cell therapies fails in the complex landscape of MCL treatment.

Nationwide Assessment of Patient Trajectories in Mantle Cell Lymphoma: The Swedish MCLcomplete Project

Mantle cell lymphoma (MCL) is a B-cell malignancy currently considered incurable. Although some patients obtain prolonged remission after first-line chemoimmunotherapy, many will need several treatment lines. Here, we present a nationwide assessment of treatment strategies, time to progression and survival in MCL. All patients diagnosed with MCL 2006-2018 were identified in the Swedish Lymphoma Register. Information on all lines of therapy was extracted from the medical records. Overall and progression-free survival (OS and PFS) were assessed through August 2021. In total, 1367 patients were included (median age, 71 years) and median follow-up was 6.8 years. Two hundred and one (15%) were managed initially with watch-and-wait, but 1235 (90%) eventually received treatment. The most frequently used first-line regimens were rituximab-bendamustine (BR) (n = 368; 30%) and Nordic MCL2 (n = 342; 28%). During follow-up, 630 patients (46%) experienced relapse/progression and 546 (40%) received second-line treatment. The most frequently used second-line regimen was BR (n = 185; 34%) but otherwise a wide variety of second-line treatments were used. Further, 382 and 228 patients experienced a second or third relapse/progression, respectively. Median PFS after first (PFS-1), second (PFS-2), third (PFS-3), and fourth (PFS-4) treatment lines was 29.4, 8.9, 4.3, and 2.7 months. Patients with early progression, defined as a PFS-1 <24 months, had an inferior median OS of 13 versus 37 months in patients with later relapse. For patients treated with frontline BR, however, time to relapse had no impact on later outcome. By use of nationwide population-based data, we provide important benchmarks for future studies of all treatment lines in MCL.

Late effects in patients with mantle cell lymphoma treated with or without autologous stem cell transplantation

Studies on late effects in patients with mantle cell lymphoma (MCL) are becoming increasingly important as survival is improving, and novel targeted drugs are being introduced. However, knowledge about late effects is limited. The aim of this population-based study was to describe the magnitude and panorama of late effects among patients treated with or without high-dose chemotherapy with autologous stem cell transplantation (HD-ASCT). The study cohort included all patients with MCL, recorded in the Swedish Lymphoma Register, aged 18 to 69 years, diagnosed between 2000 and 2014 (N = 620; treated with HD-ASCT, n = 247) and 1:10 matched healthy comparators. Patients and comparators were followed up via the National Patient Register and Cause of Death Register, from 12 months after diagnosis or matching to December 2017. Incidence rate ratios of the numbers of outpatient visits, hospitalizations, and bed days were estimated using negative binomial regression models. In relation to the matched comparators, the rate of specialist and hospital visits was significantly higher among patients with MCL. Patients with MCL had especially high relative risks of infectious, respiratory, and blood disorders. Within this observation period, no difference in the rate of these complications, including secondary neoplasms, was observed between patients treated with and without HD-ASCT. Most of the patients died from their lymphoma and not from another cause or treatment complication. Taken together, our results imply that most of the posttreatment health care needs are related to the lymphoma disease itself, thus, indicating the need for more efficient treatment options.

Treatment Outcomes and Roles of Transplantation and Maintenance Rituximab in Patients With Previously Untreated Mantle Cell Lymphoma: Results From Large Real-World Cohorts

PURPOSE

Commonly used first-line (1L) treatments for mantle cell lymphoma include high-dose cytarabine-based induction followed by autologous stem-cell transplant (ASCT) for younger patients and several chemoimmunotherapy regimens for older patients. Continuous debates exist on the role of ASCT in younger patients and maintenance rituximab (MR) after bendamustine plus rituximab (BR).

METHODS

Retrospective data from 4,216 patients with mantle cell lymphoma in the Flatiron Health electronic record-derived deidentified database diagnosed between 2011 and 2021, mostly in US community oncology settings, were evaluated for treatment patterns and outcomes. The efficacy findings with ASCT and MR were validated in an independent cohort of 1,168 patients from 12 academic centers.

RESULTS

Among 3,614 patients with documented 1L treatment, BR was the most used. Among 1,265 patients age < 65 years, 30.5% received cytarabine-based induction and 23.5% received ASCT. There was no significant association between ASCT and real-world time to next treatment (hazard ratio [HR], 0.84; 95% CI, 0.68 to 1.03; P = .10) or overall survival (HR, 0.86; 95% CI, 0.63 to 1.18; P = .4) among ASCT-eligible patients. Among MR-eligible patients, MR after BR versus BR alone was associated with a longer real-world time to next treatment (HR, 1.96; 95% CI, 1.61 to 2.38; P < .001) and overall survival (HR, 1.51; 95% CI, 1.19 to 1.92; P < .001). The efficacy findings were consistent in the validation cohort.

CONCLUSION

In this large cohort of patients treated primarily in the US community setting, only one in four young patients received cytarabine or ASCT consolidation, suggesting the need to develop treatments that can be delivered effectively in routine clinical practice. Together with the validation cohort, data support future clinical trials exploring regimens without ASCT consolidation in young patients, whereas MR should be considered for patients after 1L BR and rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone.

What is the role of up-front autologous stem cell transplantation in mantle cell lymphoma?

Up-front autologous stem cell transplantation (ASCT) is the established standard of care for younger, transplant-eligible MCL patients and is associated with a prolonged progression-free survival (PFS) benefit. However, there is no randomized controlled trial data, with therapy including rituximab and cytarabine, that has established a PFS and overall survival (OS) benefit with ASCT in the modern era. Multiple retrospective studies have failed to identify an OS benefit associated with ASCT in younger MCL patients. The high-risk patient subgroup with evidence of baseline TP53 mutation has a dismal outcome with intensive chemoimmunotherapy followed by ASCT, thus up-front ASCT is not optimal for this patient subset. Ongoing randomized clinical trials will help to clarify the role of up-front ASCT in the future. For example, the ongoing European MCL Network Triangle study incorporating ibrutinib into chemoimmunotherapy induction and maintenance with and without ASCT will help define the role of ASCT in the era of novel biologically targeted agents (ClinicalTrials.gov identifier: NCT02858258). Additionally, minimal residual disease (MRD) assessment is a powerful prognostic tool in MCL, and the ongoing Eastern Cooperative Oncology Group-American College of Radiology Imaging Network E4151 study is comparing maintenance rituximab alone vs ASCT consolidation in MCL patients who achieve remission and MRD-undetectable status post induction (ClinicalTrials.gov identifier: NCT03267433). ASCT remains a highly efficacious initial therapy for younger MCL patients; however, ultimately the decision to pursue ASCT requires discussion of risks vs benefits, incorporating patient preferences and values.