Autologous Stem Cell Transplantation for Large B-cell Lymphoma with Secondary Central Nervous System Involvement

Unmet Needs in the First-Line Treatment of Diffuse Large B-cell Lymphoma: Expert Recommendations From the Asia-Pacific Region With a Focus on the Challenging Subtypes

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma, accounting for around 30-60% of all cases. The management of DLBCL in Asia has several unmet needs due to the diversity of the population, the heterogeneity of local clinical guidelines for DLBCL and the wide disparity in resources and healthcare systems across different regions. Rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisone (RCHOP) is widely recognized as the standard first-line treatment for DLBCL; however, alternative regimens are required to improve patient outcomes in challenging subtypes, such as patients with high International Prognostic Index scores, old/frail patients, and patients with double-hit and double-expressor DLBCL or concurrent central nervous system disease. This review article draws from the expertise of practicing hematologists/oncologists in the region, with the aim of integrating data from current scientific evidence to address the unmet needs and unique socioeconomic challenges faced by challenging high risk patient groups in the Asia-Pacific region.

A prospective observational study of real-world treatment and outcome in secondary CNS lymphoma

BACKGROUND

Secondary central nervous system lymphoma (SCNSL) confers a dismal prognosis and treatment advances are constrained by the lack of prospective studies and real-world treatment evidence.

METHODS

Patients with SCNSL of all entities were included at first diagnosis and patient characteristics, treatment data, and outcomes were prospectively collected in the Secondary CNS Lymphoma Registry (SCNSL-R) (NCT05114330).

FINDINGS

279 patients from 47 institutions were enrolled from 2011 to 2022 and 243 patients (median age: 66 years; range: 23-86) were available for analysis. Of those, 49 (20 %) patients presented with synchronous (cohort I) and 194 (80 %) with metachronous SCNSL (cohort II). The predominant histology was diffuse large B-cell lymphoma (DLBCL, 68 %). Median overall survival (OS) from diagnosis of CNS involvement was 17·2 months (95 % CI 12-27·5), with longer OS in cohort I (60·6 months, 95 % CI 45·5-not estimable (NE)) than cohort II (11·4 months, 95 % CI 7·8-17·7, log-rank test p < 0.0001). Predominant induction regimens included R-CHOP/high-dose MTX (cohort I) and high-dose MTX/cytarabine (cohort II). Rituximab was used in 166 (68 %) of B-cell lymphoma. Undergoing consolidating high-dose therapy and autologous hematopoietic stem cell transplantation (HDT-ASCT) in partial response (PR) or better was associated with longer OS (HR adjusted 0·47 (95 % CI 0·25-0·89), p = 0·0197).

INTERPRETATION

This study is the largest prospective cohort of SCNSL patients providing a comprehensive overview of an international real-world treatment landscape and outcomes. Prognosis was better in patients with SCNSL involvement at initial diagnosis (cohort I) and consolidating HDT-ASCT was associated with favorable outcome in patients with PR or better.

How I treat secondary CNS involvement by aggressive lymphomas

Secondary central nervous system (CNS) lymphoma (SCNSL) is a rare but clinically challenging scenario with historically disappointing outcomes. SCNSL refers to lymphoma that has spread into the CNS concurrently with systemic disease or CNS relapse during or after frontline immunochemotherapy, presenting with or without systemic lymphoma. Diffuse large B-cell lymphoma (DLBCL) denotes the most common entity, but an increased incidence is observed in other histologies, such as Burkitt lymphoma and mantle-cell lymphoma. The incidence, timing in disease course, location, evidence supporting the use of CNS prophylaxis, and treatment pathways vary according to histology. No randomized data exist to delineate the best treatment approaches with current recommendations based on retrospective and single-arm studies. However, a regimen comprising immunochemotherapy, incorporating agents that cross the blood-brain barrier, followed by thiotepa-containing conditioning and autologous stem-cell transplant outlined in the international MARIETTA study demonstrated improvement in outcomes, representing a major accomplishment in the care of patients with DLBCL with SCNSL. Anti-CD19 chimeric antigen receptor T cell denotes a paradigm shift in the treatment of patients with systemic aggressive lymphomas, with emerging data also demonstrating efficacy without higher neurotoxicity in those with SCNSL. In this manuscript we discuss 5 clinical scenarios and review the evidence supporting our recommendations.

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.

Outcomes of Autologous Stem Cell Transplantation as a Consolidative Strategy for the Treatment of Primary and Isolated Secondary Central Nervous System Diffuse Large B Cell Lymphomas

INTRODUCTION

Standard consolidation for primary diffuse large B cell lymphoma (DLBCL) of the central nervous system (CNS) (PCNSL) is not established. This single center, retrospective observational study aims to define the outcomes of consolidative high dose chemotherapy and autologous stem cell transplantation (HDC/ASCT) in patients with PCNSL and isolated secondary CNS DLBCL (SCNSL) and evaluate the prognostic factors.

PATIENTS AND METHODS

All consecutive patients performed an HDC/ASCT for PCNSL or isolated SCNSLs between October 2012 and February 2022 were identified. Primary endpoints were progression-free survival (PFS) and overall survival (OS).

RESULTS

Among 35 patients included, 28 had PCNSL and 7 had isolated SCNSL. Median age was 51 (16-78). Males constituted 48.6%. Median follow-up after HDC/ASCT was 42.0 months. MATRIX (51.4%) and TEAM (80.0%) were the most frequent regimens of induction and conditioning, respectively. OS and PFS 1- and 2-year after HDC/ASCT were 68.0%, 57.0%, 58.0%, 48.0%, respectively. Increasing age, poor performance and comorbidities were associated with lower OS and PFS and higher non-relapse mortality (NRM). Complete response (CR) 1 at HDC/ACST was independently associated with higher OS and PFS [hazard ratio (HR): 4.67 and 6.99, respectively].

CONCLUSION

In patients < 60 years consolidative HDC/ASCT yields promising OS and PFS. Patients ≥ 60 years may less likely benefit from consolidative HDC/ASCT and should be studied further in trials of novel agents, lower doses of consolidative radiotherapy and dose-adjusted conditioning regimens. Not only age, but also comorbidities, clinical performance and response to induction correlate with outcomes. Patients with isolated SCNSL may achieve similar outcomes.