A single centre study of the treatment of relapsed primary central nervous system lymphoma (PCNSL) with single agent temozolomide

Revisiting the concept of recurrence of primary CNS lymphomas after complete response to methotrexate-based therapy: Periventricular reseeding as the predominant mechanism of recurrence

Purpose

Understanding patterns of relapse for primary central nervous system lymphoma (PCNSL) may inform mechanisms of recurrence and optimal consolidation strategies. In this study, we report patterns of relapse among patients with PCNSL who achieved a complete response to high-dose methotrexate (HD-MTX)-based chemotherapy with or without consolidation radiation therapy (RT).

Methods and Materials

We conducted an institutional retrospective analysis of patients with PCNSL who received HD-MTX-based chemotherapy between November 2001 and May 2019. Relapses were characterized as in-field (within original T1 contrasted lesion), marginal (within T2 fluid-attenuated inversion recovery but not T1), local (in-field or marginal), distant brain (no overlap), or distant (distant brain, cerebrospinal fluid, vitreous or extra-axial) and further characterized with respect to periventricular location (≤10 mm of ventricles).

Results

Seventy-eight patients with PCNSL met inclusion criteria, of whom 29 (37%) underwent consolidation RT. Median progression-free survival and overall survival were 57.0 and 66.7 months, respectively. After a median follow-up of 38.9 months, a total of 32 patients (41%) experienced recurrence. Most patients (21 [65.6%]) had a periventricular failure. Surprisingly, local recurrences (n = 11) were exclusively observed within periventricular lesions, whereas distant recurrences (n = 21) were seen in both periventricular and nonperiventricular locations (P = .009). The median time to progression was shorter for locally recurrent lesions compared with distant recurrences (13.8 vs 26.1 months; P = .03).

Conclusions

After complete response to HD-MTX, few failures occurred within initial T1 contrast-enhancing lesions and many of these may have been alternatively classified as periventricular failures. These observations argue against the use of purely focal RT consolidation for patients who achieve a complete response after HD-MTX-based chemotherapy and suggest that periventricular reseeding may have a central role in PCNSL recurrence.

Central Nervous System Lymphoma: Approach to Diagnosis and Treatment

Central nervous system lymphoma (CNSL) is a rare form of extranodal non-Hodgkin lymphoma. Central nervous system lymphoma can be primary (isolated to the central nervous space) or secondary in the setting of systemic disease. Treatment of CNSL has improved since the introduction of high-dose methotrexate and aggressive consolidation regimens. However, results after treatment are durable in only half of patients, and long-term survivors may experience late neurotoxicity, impacting quality of life. Given the rarity of this disease, few randomized prospective trials exist. This leaves many questions unanswered regarding optimal first-line and salvage treatments. Recent advances in the knowledge of pathophysiology of CNSL will hopefully help the development of future treatments. This review gives an overview of the epidemiology, pathophysiology, clinical presentation, diagnosis, and treatment of immunocompetent patients with CNSL.

High-dose methotrexate monotherapy for newly diagnosed primary central nervous system lymphoma: 15-year multicenter experience

AIM

Primary central nervous system lymphoma (PCNSL) is rare disease and shows poor prognosis although methotrexate-based chemotherapy is used. Here, we present our experiences with high-dose methotrexate (HD-MTX) monotherapy for immunocompetent patients with PCNSL at three institutions and investigate factors related to survival.

METHODS

PCNSL patients, who were histologically confirmed with diffuse large B cells and treated with HD-MTX monotherapy from 2001 to 2016, were retrospectively reviewed. Patients underwent induction chemotherapy with 8 g/m² of MTX every 10 days (maximum three cycles). Maintenance chemotherapy of 3.5 g/m² of MTX (maximum six cycles) was selectively performed depending on the response to induction chemotherapy.

RESULTS

A total of 67 patients were included. Although seven patients discontinued induction chemotherapy because of MTX toxicity, 40 (59.7%) patients showed a complete response (CR) to induction chemotherapy. Twenty-six (38.8%) and three (4.5%) patients showed a CR and partial response, respectively, after maintenance chemotherapy. Forty-one patients with recurrence or progression following HD-MTX underwent second-line treatment. Progression-free survival rates were 43% and 24% at 1 and 2 years, respectively. The median overall survival was 40.3 months. In a multivariate analysis, a radiological CR to induction chemotherapy was a significant factor related to prolonged progression-free survival and overall survival (P < 0.05).

CONCLUSION

MTX-monotherapy is tolerable in terms of adverse effects and still considered as a treatment option in patients with PCNSL. However, an additional therapeutic option should be prepared for non-CR responders to induction chemotherapy.

Pemetrexed in Recurrent or Progressive Central Nervous System Lymphoma: A Phase I Multicenter Clinical Trial

LESSONS LEARNED

The findings from this study using monotherapy with pemetrexed in a pretreated patient population are, overall, encouraging. Unlike high-dose methotrexate, which requires several days of inpatient hospitalization, pemetrexed is relatively easy to administer in the outpatient setting and remains a viable treatment option in this patient population. The maximum tolerated dose of pemetrexed administered (900 mg/m² every 2 weeks) was generally well tolerated and showed activity in patients with relapsed or refractory CNSL.

BACKGROUND

There is currently no standard salvage treatment for patients with relapsed/refractory central nervous system (CNS) lymphoma (CNSL). We report the results of a phase I study of pemetrexed, an antifolate drug with broader activity than methotrexate (MTX). We provide the safety, tolerability, and maximum tolerated dose (MTD) of pemetrexed in patients with recurrent CNSL.

METHODS

Through October 2015, 17 patients with relapsed/refractory CNSL received pemetrexed every 2 weeks with the first cohort receiving 600 mg/m² and dose escalation in increments of 300 mg/m² to a maximum of 1,200 mg/m² . Three patients were to enroll at each dose level with expansion to six patients in the event of dose-limiting toxicity. Patients with both primary CNS lymphoma (PCNSL) and secondary CNS lymphoma (SCNSL) could be enrolled.

RESULTS

Seventeen patients were evaluable with a median age of 63.7 years. Main adverse events included fatigue (82.4%), anemia (82.4%), and neutropenia (70.6%). The MTD was established at 900 mg/m² . Dose-limiting toxicities were recorded in one patient in the 600 mg/m² cohort and in two patients in the 1,200 mg/m² cohort. Fourteen patients were evaluable for response assessment; 21.4% achieved a complete response, 35.7% had a partial response, 14.3% had stable disease, and 28.6% had progressive disease. The median progression-free survival was 4.2 months. The median overall survival was 44.5 months. In the original study protocol, the plan was to add an expansion cohort of six patients at MTD level. However, the first phase of the study was characterized by slow recruitment. Therefore, after achieving the primary objective of the study and establishing the MTD, the investigators decided to amend the protocol and to close the study.

CONCLUSION

Pemetrexed administered at 900 mg/m² every 2 weeks exhibits single-agent activity in patients with recurrent CNSL; it is well tolerated, and side effects are manageable.

Introduction of novel agents in the treatment of primary CNS lymphoma

Novel insights into the pathophysiology of primary central nervous system lymphoma (PCNSL) have identified the B-cell receptor and Toll-like receptor pathway as well as immune evasion and suppressed tumor immune microenvironment as a key mechanism in the pathogenesis of PCNSL. Small molecules and novel agents targeting these aberrant pathways have been introduced into clinical trials targeting the recurrent or refractory PCNSL patient population. Agents like the Bruton tyrosine kinase (BTK) inhibitor ibrutinib or immunomodulatory drugs (IMiDs) like pomalidomide and lenalidomide have shown promising high response rates in the salvage setting. Here, we give an overview about the recent, exciting developments in PCNSL and summarize the results of clinical trials using novel agents in the recurrent and refractory salvage setting, which include immune checkpoint inhibitors, IMiDs, as well as BTK, phosphatidylinositol-3 kinase, and mammalian target of rapamycin inhibitors.

Management of primary central nervous system lymphoma

A rare tumor, primary central nervous system lymphoma can affect immunocompetent and immunocompromised patients. While sensitive to radiotherapy or chemotherapy crossing the blood-brain barrier, it often recurs. Modern treatment consists of high-dose methotrexate-based induction chemotherapy, often followed by consolidation with either radiotherapy or further chemotherapy. Neurotoxicity is however a concern with radiotherapy, especially for patients older than 60 years. The benefit of the addition of rituximab to chemotherapy is unclear. Targeted therapies and immunotherapy have been effective in some patients and are tested on a larger scale. Survival has improved in the last decade, but remains poor in older patients.

Characteristics and Outcomes of Primary Central Nervous System Lymphoma: A Retrospective Study of 91 Cases in a Chinese Population

BACKGROUND

Primary central nervous system lymphoma (PCNSL) is a rare disease affecting the brain, leptomeninges, spinal cord, cerebrospinal fluid, or vitreoretinal compartment, without evidence of systemic disease. Prognosis is still poor after intensive methotrexate-based chemotherapy.

METHODS

Clinical data of 91 patients treated in a tertiary referral center during a 13-year period were retrospectively reviewed.

RESULTS

The estimated median progression-free survival and overall survival (OS) for the entire cohort were 39.1 months (95% confidence interval [CI], 14.1-64.0 months) and 54.5 months (95% CI, 28.9-80.1 months), respectively. Estimated 5-year progression-free survival and OS were 37.0% ± 6.5% and 47.5% ± 7.5%. Survival was associated with cycles of methotrexate only in multivariate analysis. Seventy-four patients received methotrexate-based chemotherapy after diagnosis. Thirty-nine patients experienced disease progression. Patients with relapsed/refractory disease had a poor survival, with median second OS (calculated from the date of first disease progression to the time of death from any cause) being 7.2 months (95% CI, 2.5-12.00 months). Three patients responded to ibrutinib after disease progression and incurred no fungal infection.

CONCLUSIONS

The outcomes of patients with PCNSL treated in our cohort are still poor. Relapse or refractory PCNSL and those not tolerating aggressive chemotherapy urgently require new approaches to improve their still dismal prognosis. Novel agents such as ibrutinib have shown promising clinical activity. Future studies should focus on the predictive biomarkers for the treatment of PCNSL with novel agents to provide precision medicine for PCNSL.

Stereotactic Brachytherapy with Iodine-125 Seeds Plus Temozolomide Induced Complete and Durable Remission in a Patient with Recurrent Primary Central Nervous System Lymphoma

BACKGROUND

The optimal treatment of recurrent primary central nervous system lymphoma (PCNSL) has not yet been determined. We report a patient with recurrent PCNSL who has been successfully treated with stereotactic brachytherapy (SBT) with iodine-125 seeds plus temozolomide (TMZ).

CASE DESCRIPTION

A 51-year-old man who underwent left occipital lobe tumor resection 11 years earlier presented with a 1-month history of right hand weakness. Magnetic resonance imaging (MRI) revealed a recurrent PCNSL, which was confirmed by pathological examination. He was treated with SBT plus TMZ. At 1 month after surgery, a repeat MRI revealed nearly complete disappearance of the lesion. At 13.5 months postsurgery, the patient was neurologically intact except for right homonymous hemianopia, and follow-up MRI did not reveal a recurrent tumor.

CONCLUSIONS

To our knowledge, this is the first case of recurrent PCNSL successfully treated with SBT plus TMZ. Further randomized studies are needed to confirm the therapeutic impact of this new method.

Treatment of Primary Central Nervous System Lymphoma: From Chemotherapy to Small Molecules

Primary central nervous system lymphoma (PCNSL) is a rare form of extranodal non-Hodgkin lymphoma that is typically confined to the brain, eyes, and cerebrospinal fluid (CSF) without evidence of systemic spread. PCNSL is an uncommon tumor, and only four randomized trials and one phase III trial have been completed so far, all in the first-line setting. The prognosis of patients with PCNSL has improved during the past few decades with the introduction of high-dose methotrexate (HD-MTX), which now serves as the backbone of all first-line treatment regimens. Despite recent progress, results after treatment are durable in half of patients, and therapy can be associated with late neurotoxicity. Novel insights into the pathophysiology of PCNSL have identified the B-cell receptor (BCR) pathway as a key mechanism in the pathogenesis of PCNSL. The use of novel agents targeting components of the BCR pathway, namely the Bruton tyrosine kinase (BTK) inhibitor ibrutinib, and immunomodulatory drugs (IMIDs) like lenalidomide and pomalidomide, has so far been limited to patients who have recurrent/refractory PCNSL with promising high response rates. Within the past 5 years, there has been a peak in clinical trials investigating small molecules and novel reagents in the recurrent/refractory setting, including immune checkpoint inhibitors, IMIDs, and BTK and PI3K/AKT/mTOR inhibitors.

Primary CNS Lymphoma

Primary CNS lymphoma (PCNSL) is a rare form of extranodal non-Hodgkin lymphoma that is typically confined to the brain, eyes, and cerebrospinal fluid without evidence of systemic spread. The prognosis of patients with PCNSL has improved during the last decades with the introduction of high-dose methotrexate. However, despite recent progress, results after treatment are durable in half of patients, and therapy can be associated with late neurotoxicity. PCNSL is an uncommon tumor, and only four randomized trials and one phase III trial have been completed so far, all in the first-line setting. To our knowledge, no randomized trial has been conducted for recurrent/refractory disease, leaving many questions unanswered about optimal first-line and salvage treatments. This review will give an overview of the presentation, evaluation, and treatment of immunocompetent patients with PCNSL.

Efficacy and safety of pemetrexed on recurrent primary central nervous system lymphomas in China: a prospective study

BACKGROUND

Pemetrexed, a new and novel agent for primary central nervous system lymphomas (PCNSLs), has shown to be efficient as a savage therapy for recurrent PCNSLs. However, more studies are needed. A prospective study was performed on 17 recurrent PCNSL patients with pemetrexed at Shandong Tumor Hospital in China to assess the efficacy and safety of pemetrexed for recurrent PCNSL patients.

MATERIALS AND METHODS

The medical records and imaging data on all the cases of recurrent PCNSL patients with pemetrexed in our study were collected during August 2012 and April 2015. Folic acid, B₁₂, and dexamethasone were used to induce toxicities related to pemetrexed. Patients were treated with pemetrexed at a dose of 900 mg/m² intravenously every 3 weeks, and one cycle consists of 6 weeks.

RESULTS

A total of 17 cases of recurrent PCNSL patients were enrolled in our study, including 10 males and 7 females with a median age of 66.2 years (ranging from 35 to 81). After the treatment, five cases had complete remission, with partial remission in five cases, stable disease in four cases, and progressive disease in three cases. Consequently, the overall response rate was 58.8%, and the disease control rate was 82.4%. The median overall survival was 7.8 months (95% confidence interval: 5.9-9.6 months) in the study of recurrent PCNSL patients.

CONCLUSION

This study has been the first clinical trial that applied pemetrexed to treat recurrent PCNSL patients in China, and results indicated that chemotherapy using large pemetrexed may become an effective treatment for PCNSL recurrence with modest toxicity.

Primary CNS lymphoma at first relapse/progression: characteristics, management, and outcome of 256 patients from the French LOC network

BACKGROUND

Treatment of relapsed/refractory (R/R) primary CNS lymphoma (PCNSL) is poorly defined, because randomized trials and large studies are lacking. The aim of this study was to analyze the characteristics, management, and outcome of R/R PCNSL patients after first-line therapy in a nationwide cohort.

METHODS

We analyzed R/R PCNSL patients following first-line treatment who had been prospectively registered in the database of the French network for oculocerebral lymphoma (LOC) between 2011 and 2014.

RESULTS

Among 563 PCNSL patients treated with first-line therapy, we identified 256 with relapsed (n = 93, 16.5%) or refractory (n = 163, 29.0%) disease. Patients who were asymptomatic at relapse/progression (25.5%), mostly diagnosed on routine follow-up neuroimaging, tended to have a better outcome. Patients who received salvage therapy followed by consolidation (mostly intensive chemotherapy plus autologous hematopoietic stem cell transplantation [ICT + AHSCT]) experienced prolonged survival compared with those who did not receive salvage or consolidation therapy. Independent prognostic factors at first relapse/progression were: KPS ≥ 70 vs KPS < 70), sensitivity to first-line therapy (relapsed vs refractory disease), duration of first remission (progression-free survival [PFS] ≥1 y vs <1 y), and management at relapse/progression (palliative care vs salvage therapy). Patients who relapsed early after first-line therapy (ie, PFS < 1 y) had a poor outcome, comparable to that of refractory patients. Conversely, patients experiencing late relapses (PFS ≥ 1 y) and/or undergoing consolidation with ICT + AHSCT experienced prolonged survival.

CONCLUSIONS

About a third of PCNSL patients are primary refractory to first line treatment. We identified several independent prognostic factors that can guide the management of R/R PCNSL patients.

Primary CNS lymphoma

Primary diffuse large B-cell lymphoma (DLBCL) of the central nervous system is an aggressive malignancy that exhibits unique biological features and characteristic clinical behaviour, with overall long-term survival rates of around 20–40 %. Clinical outcome has improved following the advent of chemoradiation protocols incorporating high-dose methotrexate in the mid-1980s, but disease relapse and adverse neurocognitive sequelae remain major clinical challenges. To address this, investigators have focused on improving drug therapy with novel cytotoxic combinations, monoclonal antibody therapy, and intensive chemotherapy consolidation approaches, in an attempt to improve disease control whilst reducing the requirement for whole-brain radiotherapy. Outcomes for patients that are older, immunocompromised, or have relapsed/refractory disease remain unsatisfactory and there is a paucity of clinical trial data to guide treatment of these groups. This review highlights recent advances in pathobiology, imaging, and clinical management of PCNSL and looks ahead to research priorities for this rare and challenging lymphoid malignancy.

Pemetrexed plus rituximab as second-line treatment for primary central nervous system lymphoma

The aim of the study was to determine the efficacy and toxicity of pemetrexed plus rituximab in patients with primary central nervous system lymphoma, who had undergone treatment with high-dose (HD) methotrexate-based regimens. Patients who had failed HD methotrexate-based regimens treatment had ECOG performance status ranging from 0 to 2. Twenty-seven patients received pemetrexed plus rituximab as second-line treatment. Rituximab 375 mg/m(2) was administered on day 0 and pemetrexed 500 mg/m(2) was administered on day 1 every 3 weeks. Six patients (22.2 %) experienced CR, 11 patients (40.7 %) had PR, eight patients (29.6 %) had SD, and two patients had PD. The response rate was 62.9 %. The median time to progression (PFS) was 6.9 months (95 % CI, 5.6-8.3), and the median overall survival was 11.2 months (95 % CI, 9.1-13.4). In the subgroup analysis, PFS had a significant difference among the low level of serum miR-21 and high level of serum miR-21. PFS was 9.0 (95 % CI, 6.3-11.6) and 5.7 months (95 % CI, 4.6-6.9, log rank = 0.015), respectively. None of the patient experienced grade 4 toxicity. A regimen of pemetrexed combined with rituximab is marginally effective and well tolerated in patients with PCNSL who had failed HD methotrexate-based regimens first-line treatment.

Retrospective study of pemetrexed as salvage therapy for central nervous system lymphoma

There is currently no standard therapy for recurrent or chemotherapy-refractory central nervous system lymphoma (CNSL). Pemetrexed has been reported to have activity in patients with primary CNSL (PCNSL). The use of pemetrexed in secondary CNS lymphoma (SCNSL) has not previously been reported. Here we retrospectively review the outcomes and toxicities of standard and modified doses of pemetrexed as salvage therapy in 18 PCNSL and 12 SCNSL patients. The overall response rate for PCNSL patients was 64.7 %, all of whom achieved a complete response (CR). The median progression-free survival (PFS) was 5.8 months. For the SCNSL patients, RR was 58.3 % with 2 CR (16.7 %); the median PFS was 2.5 months. Grade ≥3 adverse events included leukopenia in 5 patients (16.7 %), neutropenia in 1 patient (3.3 %), and fatigue in 3 patients (10.0 %). 3 patients died while on treatment, 2 due to infections and 1 due to pulmonary embolism. Our results indicate that pemetrexed has activity as salvage therapy in recurrent PCNSL, even with modified dosing, but outcomes trend towards less favorable in SCNSL.