Incidence of central nervous system relapses in patients with DLBCL treated with lenalidomide as maintenance after R-CHOP

Relapsed isolated CNS lymphoma treated with radiotherapy and intrathecal methotrexate followed by high-dose intravenous methotrexate, rituximab, and temozolomide: A case report

Key Clinical Message

Optimized treatments for relapsed isolated CNS lymphoma (RI-SCNSL) remains under investigation. Temozolomide combination-based therapy, which is often used in glioblastoma may be used as potential treatment in RI-SCNSL.

Abstract

One of the most common types of non-Hodgkin lymphoma (NHL) is diffuse large B-cell lymphoma (DLBCL). Despite advances in treatment, relapsed isolated CNS lymphoma (RI-SCNSL) from DLBCL remains an issue. The optimal approach in RI-SCNSL remains an area of active investigation as currently there is no high level of evidence for the treatments due to lack of randomized studies. In this case report, we present a DLBCL patient with CNS recurrence treated radiotherapy and intrathecal methotrexate (MTX) followed by intravenous high-dose MTX, rituximab, and temozolomide. To the best of our knowledge, this is the first case report describing RI-SCNSL treated with the regiments above which also include temozolomide which is used for glioblastoma.

Central nervous system prophylaxis in diffuse large B-cell lymphoma: What does the evidence tell us?

Secondary involvement of the central nervous system (CNS) by diffuse large b-cell lymphoma (DLBCL) is a rare yet often catastrophic event for DLBCL patients. As standard first-line therapy for DLBCL with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) does not cross the blood-brain barrier, one approach to lessen the risk of CNS relapse has been to include additional agents, primarily methotrexate, directed at the CNS with standard R-CHOP although the timing, dose, and mode of administration differs widely across treating physicians. This practice derives from decades of non-randomized, often retrospective data with inconsistent outcomes. The current available tools and risk models are imprecise in their ability to predict which patients are truly at risk of secondary CNS relapse and more recent, large-scale real-world analyses call into question these longstanding practices. In a field lacking any prospective, randomized studies, this review synthesizes the available data investigating the utility of CNS prophylaxis in patients with DLBCL receiving 1st line therapy.

Management of primary and secondary CNS lymphoma

Central nervous system (CNS) lymphoma has traditionally had very poor outcomes however advances in management have seen dramatic improvements and long-term survival of patients. In primary CNS lymphoma there are now randomised trial data to inform practice, however secondary CNS lymphoma has a lack of randomised trial data and CNS prophylaxis remains a contentious area. We describe treatment strategies in these aggressive disorders. Dynamic assessment of patient fitness and frailty is key throughout treatment alongside delivery of CNS-bioavailable therapy and enrolment in clinical trials. Intensive high-dose methotrexate-containing induction followed by autologous stem cell transplantation is preferred for patients who are fit. Less intensive chemoimmunotherapy, whole brain radiotherapy and novel therapies may be reserved for patients unfit or chemoresistant. It is essential to better define patients at increased risk of CNS relapse, as well as effective prophylactic strategies to prevent it. Future prospective studies incorporating novel agents are key.

Real-world data for lenalidomide maintenance in responding patients of diffuse large B-cell lymphoma

BACKGROUND

Approximately 40% patients of diffuse large B-cell lymphoma (DLBCL) would develop disease recurrence/progression after first-line R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) induction therapy, with highly poor prognosis. An effective strategy to prolong the survival of this patient population is the additional single-drug maintenance therapy. lenalidomide, an immunomodulatory drug with oral activity, has direct anti-tumor activity and indirect effects mediated by multiple immune cells in the tumor microenvironment, such as B, T, natural killer (NK), and dendritic cells. Combining its controllable toxicity, it is promising in long-term maintenance therapy. This study aims at evaluating the clinical effect of lenalidomide maintenance therapy in responding DLBCL patients with R-CHOP treatment.

METHODS

This retrospective study was devised in DLBCL cases who obtained complete response (CR) or partial response (PR) following 6-8 cycles of R-CHOP treatment between January 1, 2015 and July 31, 2019. Patients (n = 141) included were respectively assigned to receive lenalidomide maintenance treatment (lenalidomide, n = 50) and drug-free maintenance treatment (control, n = 91) after CR/PR. lenalidomide was provided orally at 25 mg/day for 10 days, with a cycle of 21 days and a treatment course of 2 years. Progression-free survival (PFS) was taken as the primary outcome.

RESULTS

Of the total 141 subjects, the median follow-up time was 30.9 months (range, 5.7-68.9 months). The 2-year PFS was 84% (95% CI: 74%-94%) in the lenalidomide group and 53% (95% CI: 43%-63%) in the control group. The median PFS of the lenalidomide group was not reached, and that of the control group was 42.9 months (HR = 0.32; 95% CI: 0.16-0.63; p = 0.001). No remarkable difference in overall survival (OS) between the two groups was indicated (HR = 0.42; 95% CI: 0.16-1.12; p = 0.08). Central nervous system (CNS) recurrence happened in 5 patients (5.5%) of the control group, while none of the patients with lenalidomide had CNS recurrence. Additionally, neutropenia and cutaneous reactions were the most common Grade 1-2 adverse reactions after lenalidomide treatment, and neutropenia was the most frequent Grade 3-4 adverse reaction.

CONCLUSION

Two-year lenalidomide maintenance treatment can significantly prolong the PFS of DLBCL patients who obtained CR/PR to first-line R-CHOP treatment.

Prevention and management of secondary central nervous system lymphoma

Secondary central nervous system (CNS) lymphoma (SCNSL) is defined by the involvement of the CNS, either at the time of initial diagnosis of systemic lymphoma or in the setting of relapse, and can be either isolated or with synchronous systemic disease. The risk of CNS involvement in patients with diffuse large B-cell lymphoma is approximately 5%; however, certain clinical and biological features have been associated with a risk of up to 15%. There has been growing interest in improving the definition of patients at increased risk of CNS relapse, as well as identifying effective prophylactic strategies to prevent it. SCNSL often occurs within months of the initial diagnosis of lymphoma, suggesting the presence of occult disease at diagnosis in many cases. The differing presentations of SCNSL create the therapeutic challenge of controlling both the systemic disease and the CNS disease, which uniquely requires agents that penetrate the blood-brain barrier. Outcomes are generally poor with a median overall survival of approximately 6 months in retrospective series, particularly in those patients presenting with SCNSL after prior therapy. Prospective studies of intensive chemotherapy regimens containing high-dose methotrexate, followed by hematopoietic stem cell transplantation have shown the most favorable outcomes, especially for patients receiving thiotepa-based conditioning regimens. However, a proportion of patients will not respond to induction therapies or will subsequently relapse, indicating the need for more effective treatment strategies. In this review we focus on the identification of high-risk patients, prophylactic strategies and recent treatment approaches for SCNSL. The incorporation of novel agents in immunochemotherapy deserves further study in prospective trials.

The role of central nervous system (CNS) prophylaxis in preventing DLBCL patients from CNS relapse: A network meta-analysis

BACKGROUND

Secondary central nervous system (CNS) relapses are an uncommon yet devastating complication in diffuse large B cell lymphoma (DLBCL). Although several prophylaxis attempts were employed clinically in order to reduce the CNS relapse rate, the optimal management remained uncertain.

METHODS

We employed conventional meta-analysis along with Network meta-analysis to investigate an optimal prophylactic strategy. The primary outcome was CNS relapse rate.

RESULTS

A total of thirty-six studies comprising 5 RCTs, one clinical trial and 30 observational studies were included. Rituximab overall was superior in reducing CNS relapse rate, and the statistical significance exists (RR 0.79(0.68-0.93), p = 0.004). In rituximab era, none of intravenous, intrathecal administration or novel target agents could significantly decrease CNS relapse rate in high CNS risk patients. Intensive chemotherapy regimen containing HD-MTX with HD-Ara-C (SUCRA 93.4 %) was ranked as the first in reducing CNS relapse rate followed by no prophylaxis (SUCRA 57.5 %), HD-MTX (SUCRA 53.1 %), IT (SUCRA 34.5 %) and lenalidomide maintenance (SUCRA 11.5 %). In addition, intercalated HD-MTX had a trend of reducing CNS relapse but without statistical significance (RR 0.86(0.44-1.68), p = 0.67). However, i-HD-MTX was associated with increased grade 3-4 toxicities and prolonged inpatient stay. Early HD-MTX exposure also increased the treatment related death.

CONCLUSION

Our network meta-analysis provides an overview of the relative efficacy of all available CNS prophylaxis strategies in DLBCL. In rituximab era, none of intravenous, intrathecal administration or novel target agents could significantly decrease CNS relapse rate in high CNS risk patients. Further studies with prospective, randomized clinical trials as well as with more focus on novel target agents that could spread blood-brain barriers are suggested.