Topotecan as salvage therapy for relapsed or refractory primary central nervous system lymphoma

New hopes in relapsed refractory primary central nervous system lymphoma

PURPOSE OF REVIEW

Patients with relapsed/refractory primary central nervous system lymphoma (rrPCNSL) have poor prognosis, with a median survival after relapse of 6.8 months. In this review, we discuss the evolving landscape and the possible future directions related to this important unmet clinical need.

RECENT FINDINGS

The modern two-phase approach for newly diagnosed PCNSL based on an induction using high-dose methotrexate (HD-MTX) combinations and a subsequent consolidation, has significantly improved the outcome in this setting. However, this strategy is able to cure more or less 50% of patients. rrPCNSL patients have a very poor prognosis with a reported 5-year overall survival of 18%. Late relapses (after third year) and use of high-dose chemotherapy and autologous stem cell transplantation (HDT-ASCT) represent important factors associated with a better outcome in this setting. On the basis of the growing acquisition of knowledge on the molecular characteristics of PCNSL, the use of non-chemotherapeutic drugs such as bruton tyrosine kinase inhibitors (BTK-is), immunomodulatory drugs (IMiDs) and immune checkpoint blockers (ICBs) is increasing in the last years along with the introduction of novel approaches (CAR-T cells and blood--brain barrier disruption). However, despite high responses in some cases, durations are often short, translating in outcome results still unsatisfactory.

SUMMARY

Treatment of rrPCNSL patients is challenging. As no standard of care exist in this setting, it is of paramount importance to acquire new knowledge related to this condition and start multidisciplinary collaboration in order to improve pts outcome.

Long-term survival after salvage pemetrexed for refractory primary T-cell lymphoma of the CNS

Primary T-cell CNS lymphoma is a rare and aggressive malignancy. High-dose methotrexate (MTX) based chemotherapy regimens are used as standard first-line treatment, followed by consolidative strategies to improve the duration of response. Although MTX-based therapy has been shown to be efficacious, treatment options for MTX-refractory disease are not well-defined. Here, we report a case of a 38-year-old man with refractory primary T-cell CNS lymphoma who demonstrated a complete response to pemetrexed treatment. He subsequently received conditioning chemotherapy consisting of thiotepa, busulfan and cyclophosphamide followed by autologous stem cell transplantation. The patient continues to remain recurrence-free to date at 9 years post-treatment.

Treatment Options for Recurrent Primary CNS Lymphoma

OPINION STATEMENT

Primary CNS lymphoma (PCNSL) constitutes a rare extranodal variant of non-Hodgkin lymphoma (NHL) with an annual incidence of 0.45/100,000. Given the paucity of large prospective clinical trials, there is no consensus treatment for refractory or relapsed (r/r) PCNSL, and available strategies are largely based on retrospective analyses. Patient age, performance status, previously administered treatment, duration of response, and molecular characteristics guide selection of salvage therapy. Patients with a good performance status (KPS >70), particularly ≤65 years, and adequate organ function should be considered for salvage polychemotherapy. Based on its high overall response rate even in the relapsed setting, we choose high-dose (≥ 3.5g/m²) methotrexate (HD-MTX) based regimens, e.g., R-MPV (rituximab, HD-MTX, procarbazine, and vincristine), for remission re-induction as long as patients were sensitive to first line HD-MTX-based regimens, especially when duration of previous response was ≥ 1 year. Following successful remission induction, we choose myeloablative chemotherapy (e.g., thiotepa, busulfan, cyclophosphamide) and subsequent autologous stem cell transplant in curative intent whenever feasible. Alternatively, conventional chemotherapy regimens (for example, monthly HD-MTX) or low-dose whole-brain radiation therapy (WBRT) are selected for consolidation in non-transplant candidates in complete remission. In cases of HD-MTX refractory disease or contraindications, we use pemetrexed; temozolomide/rituximab; high-dose cytarabine; or whole brain radiation for remission induction. Clinical trial participation is considered as well. Emerging therapies for upfront or salvage therapy under ongoing investigation include bruton tyrosine kinase inhibition (e.g., ibrutinib), immunomodulatory drugs (e.g., lenalidomide), immune checkpoint inhibitors (ICI, e.g., nivolumab), and chimeric antigen receptor T (CAR-T) cell therapy.

Systemic Relapse in a Young Adult Patient with Primary CNS Diffuse Large B-Cell Lymphoma

Primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL) is a rare form of non-Hodgkin's lymphoma, characterized by an aggressive disease course. While CNS relapse is common, systemic relapse is rare with no consensus on optimal treatment. This paper presents an unusual case of advanced PCNS-DLBCL with systemic relapse, including adrenal gland involvement. A review of the existing literature and a discussion on the management of systemic relapse in PCNS-DLBCL is also provided.

High-Dose Chemotherapy with Autologous Hematopoietic Stem Cell Transplantation in Relapsed or Refractory Primary CNS Lymphoma: A Retrospective Monocentric Analysis of Long-Term Outcome, Prognostic Factors, and Toxicity

High-dose chemotherapy with autologous stem cell transplantation (HCT-ASCT) is reportedly an effective treatment strategy in relapsed or refractory primary CNS lymphoma (r/r PCNSL); however, only selected patients are eligible for this treatment. We retrospectively analyzed outcome, prognostic factors, and toxicity in 59 patients with r/r PCNSL planned to receive HCT-ASCT at our institution between January 2005 and December 2021 (n = 33 < 65 years; n = 26 ≥ 65 years). Median follow-up was 65 months (95% CI 21−109). Median age was 63 years (range 29−76), median Karnofsky performance score (KPS) was 80 (range 30−100). In the entire cohort of 59 patients, median overall survival (OS) was 14 months (95% CI 0−37). In 50/59 (84.7%) patients who completed HCT-ASCT, median progression free survival (PFS) was 12 months (95% CI 3−21) and median OS 30 months (95% CI 0−87). 1-year, 2-year, and 5-year OS rates of 61.2%, 52.3% and 47.1%, respectively, were observed. Six patients (10.2%) died related to treatment (1 during induction treatment, 5 post HCT-ASCT). Age was not prognostic. On univariate analysis, KPS ≥ 80 (p = 0.019) and complete or partial remission before HCT-ASCT (p = 0.026) were positive prognosticators of OS; on multivariate analysis, KPS (p = 0.043) and male gender (p = 0.039) had an impact on OS. The 5-year OS rate in patients with progressive or stable disease after induction treatment was 32.7%. In summary, HCT-ASCT was effective and feasible in this cohort of r/r PCNSL patients. Clinical state, remission status before HCT-ASCT, and gender influenced survival, whereas age did not influence outcome in this study.

Pemetrexed for Recurrent Primary Central Nervous System Lymphoma in the Elderly: Results of a Retrospective Study

Aim

Primary central nervous system lymphoma (PCNSL) is an aggressive, destructive, and rapidly progressive malignant brain tumor. Although aggressive therapies were studied trying to increase the median survival of PCNSL, the high relapse rate of PCNSL is still a big problem for the oncology medicine. A retrospective study was made to evaluate the efficacy and safety of pemetrexed in the treatment of patients with recurrent PCNSL.

Methods

Twenty-three confirmed recurrent PCNSL patients were selected during April 2012 and August 2016. Dexamethasone, B12, and folic acid were used to produce the toxicity related to pemetrexed. The patients were intravenously given pemetrexed (900 mg/m2) every three weeks for 6 weeks.

Results

After the treatment, 7 patients were in complete remission, 6 patients in partial remission, 4 patients in stable condition, and 6 patients in progression. There were 56.5% and 73.9% in the overall response rate and the disease control rate, respectively. The median overall survival (OS) was 6.6 months (95% CI, 4.6-8.6).

Conclusion

This study has been the first time to evaluate the safety and effectiveness of pemetrexed on elderly recurrent PCNSL patients. Results demonstrate that using high-dose pemetrexed might be a feasible and effective treatment for recurrent PCNSL in the elderly, and clinical trials should be conducted to further confirm it.

Primary Central Nervous System Lymphoma in Elderly Patients: Management and Perspectives

The management of elderly patients suffering from primary central nervous system (CNS) lymphoma, who represent a rapidly growing population, is challenging. Despite the advances made in PCNSL treatment, the prognosis in older patients remains unsatisfactory. The high risk of systemic and CNS toxicity induced by a high-dose chemotherapy regimen and radiation therapy, respectively, limits the use of consolidation phase treatments in elderly patients and contributes to the poor outcome of these patients. Here, we review the current treatment strategies and ongoing trials proposed for elderly PCNSL patients.

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.

Relapsed Primary Central Nervous System Lymphoma: Current Advances

Primary central nervous system lymphoma is an invasive malignant lymphoma confined to the central nervous system. Although patients undergoing first-line treatment can achieve complete response, most of them still relapse within two years. Relapsed lymphoma is derived from occult lymphoma cells, and B cell receptor pathway activation and immune escape are the key mechanisms for the pathogenesis of PCNSL. Most relapses are in the central nervous system, a small number of relapses are isolated systemic relapses, and clinical symptoms occur early and vary. Current treatments for relapse include high-dose methotrexate rechallenge and other regimens of chemotherapy, whole-brain radiation therapy, hematopoietic stem-cell transplantation, targeted therapy and immunotherapy, which have become promising treatments. The overall prognosis of relapsed PCNSL is very poor, although it is affected by many factors. This article summarizes the mechanisms, related factors, clinical features, follow-up, treatment and prognosis of relapsed primary central nervous system lymphoma.

Challenges in the Treatment of Newly Diagnosed and Recurrent Primary Central Nervous System Lymphoma

Primary central nervous system lymphomas (PCNSLs) are rare cancers of the central nervous system (CNS) and are predominantly diffuse large B-cell lymphomas of the activated B-cell (ABC) subtype. They typically present in the sixth and seventh decade of life, with the highest incidence among patients aged >75 years. Although many different regimens have demonstrated efficacy in newly diagnosed and relapsed or refractory PCNSL, there have been few randomized prospective trials, and most recommendations and treatment decisions are based on single-arm phase II trials or even retrospective studies. High-dose methotrexate (HD-MTX; 3-8 g/m2) is the backbone of preferred standard induction regimens. Various effective regimens with different toxicity profiles can be considered that combine other chemotherapies and/or rituximab with HD-MTX, but there is currently no consensus for a single preferred regimen. There is controversy about the role of various consolidation therapies for patients who respond to HD-MTX-based induction therapy. For patients with relapsed or refractory PCNSL who previously experienced response to HD-MTX, repeat treatment with HD-MTX-based therapy can be considered depending on the timing of recurrence. Other more novel and less toxic regimens have been developed that show efficacy in recurrent disease, including ibrutinib, or lenalidomide ± rituximab. There is uniform agreement to delay or avoid whole-brain radiation therapy due to concerns for significant neurotoxicity if a reasonable systemic treatment option exists. This article aims to provide a clinically practical approach to PCNSL, including special considerations for older patients and those with impaired renal function. The benefits and risks of HD-MTX or high-dose chemotherapy with autologous stem cell transplantation versus other, better tolerated strategies are also discussed. In all settings, the preferred treatment is always enrollment in a clinical trial if one is available.

Systemic Approach to Recurrent Primary CNS Lymphoma: Perspective on Current and Emerging Treatment Strategies

There is no uniform standard of care for the treatment of refractory or recurrent primary central nervous lymphoma (r/r PCNSL). Many different systemic treatment regimens have been studied, but available data are based on small prospective or retrospective reports. There have been no randomized controlled trials in r/r PCNSL to date. Here, we provide an overview of published systemic regimens for the treatment of r/r PCNSL, as well as therapies that are under investigation. In addition, based on available data, we propose strategies of how to approach choice of therapy for different groups of patients in this disease setting. Patients can be mainly divided into three groups: 1) patients suitable for a re-challenge with high-dose methotrexate (HD-MTX)-based regimens and that may or may not be candidates for consolidation with high-dose chemotherapy with autologous stem cell transplant, 2) patients refractory to HD-MTX or that had early relapse, but suitable for an aggressive treatment strategy with re-induction with non-MTX-based therapy, possibly followed by high-dose chemotherapy with autologous transplant, and 3) patients not suitable for re-treatment with HD-MTX and that are not candidates for aggressive therapy. As PCNSL is a rare disease and as there is urgent need for better outcomes in r/r PCNSL, clinical trial participation is encouraged, especially in elderly or frail patients who are not candidates for high-dose chemotherapy and transplant.

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.

Primary Central Nervous System Lymphoma: Molecular Pathogenesis and Advances in Treatment

Primary central nervous system lymphoma (PCNSL) is a group of extranodal non-Hodgkin lymphoma that exhibits specific biological characteristics and clinical behavior, with an aggressive disease course and unsatisfactory patient outcomes. It is of great importance to identify aberrant genetic loci and important molecular pathways that might suggest potential targets for new therapeutics and provide prognostic information. In this review, we listed various genetic and epigenetic alterations that are involved in PCNSL pathogenesis. In the aspect of treatment, we summarized the related literatures and evaluated the efficacy of surgery, induction chemotherapy, radiotherapy, intrathecal chemotherapy, and autologous stem cell transplantation in PCNSL. We also proposed the possible new agents for recurrent and relapse PCNSL based on the result of recent clinical researches.

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.

Immunochemotherapy using rituximab (RTX) and high-dose methotrexate (HD-MTX): an evaluation of the addition of RTX to HD-MTX in recurrent primary central nervous system lymphoma (PCNSL)

Background

There is increasing evidence that MTX-based chemotherapy is superior to HD-MTX alone. Rituximab (RTX) is effective in a variety of B-cell lymphomas and may enter the brain. The purpose of this study is to evaluate the addition of RTX to HD-MTX in recurrent primary central nervous system lymphoma (PCNSL).

Methods

Patients diagnosed with recurrent PCNSL at our institution between 2004 and 2009 were treated with HD-MTX (3.5-5.5 g/m2) every 2 weeks. From 2010, RTX (375 mg/m2) was administered every 2 weeks along with HD-MTX.

Results

Fifteen recurrences in 10 patients were treated with HD-MTX alone (MTX group). Another 15 recurrences in 10 patients were treated with RTX and HD-MTX (RTX group). In 13 (86.6%) of the 15 recurrences in both groups the pre-planned chemotherapy cycles were completed. In the MTX group, 10/15 (66.6%) recurrences achieved a complete response (CR/CRu), 2/15 (13.3%) recurrences achieved a partial response (PR) and 3/15 (20%) recurrences had progressive disease (PD). In the RTX group, the CR/CRu, PR and PD rates were the same as that in the MTX group. The median time to tumor progression (mTTP) was 9.1 months (range, 1.4-120.9 months) in the MTX group and 7.8 months (range, 0.9-52.3 months) in the RTX group. We found no significant difference in mTTP (9.1 vs. 7.8 months, HR 1.02, 95% CI 0.48-2.18, P = 0.94) between the two groups. All treatment-related toxicities were manageable without any severe events.

Conclusions

The addition of RTX to HD-MTX may not be a promising strategy for recurrent PCNSL. A future study with a larger sample size, longer follow-up, or different RTX dosing/schedule is warranted.

High-dose chemotherapy with autologous haematopoietic stem cell support for relapsed or refractory primary CNS lymphoma: a prospective multicentre trial by the German Cooperative PCNSL study group

To investigate safety and efficacy of high-dose chemotherapy followed by autologous stem cell transplantation (HCT-ASCT) in relapsed/refractory (r/r) primary central nervous system lymphoma (PCNSL), we conducted a single-arm multicentre study for immunocompetent patients (<66 years) with PCNSL failing high-dose methotrexate)-based chemotherapy. Induction consisted of two courses of rituximab (375 mg/m²), high-dose cytarabine (2 × 3 g/m²) and thiotepa (40 mg/m²) with collection of stem cells in between. Conditioning for HCT-ASCT consisted of rituximab 375 mg/m², carmustine 400 mg/m² and thiotepa (4 × 5 mg/kg). Patients commenced HCT-ASCT irrespective of response after induction. Patients not achieving complete remission (CR) after HCT-ASCT received whole-brain radiotherapy. Primary end point was CR after HCT-ASCT. We enrolled 39 patients; median age and Karnofsky performance score are 57 years and 90%, respectively. About 28 patients had relapsed and 8 refractory disease. About 22 patients responded to induction and 32 patients commenced HCT-ASCT. About 22 patients (56.4%) achieved CR after HCT-ASCT. Respective 2-year progression-free survival (PFS) and overall survival (OS) rates were 46.0% (median PFS 12.4 months) and 56.4%; median OS not reached. We recorded four treatment-related deaths. Thiotepa-based HCT-ASCT is an effective treatment option in eligible patients with r/r PCNSL. Comparative studies are needed to further scrutinise the role of HCT-ASCT in the salvage setting.

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.

Case-based review: primary central nervous system lymphoma

Primary CNS lymphoma (PCNSL) is a rare diffuse large B-cell lymphoma originating within the central nervous system. The overall incidence of PCNSL is rising, particularly in the elderly population. Immunosuppression is a strong risk factor, but most patients with this tumor are apparently immunocompetent. Diagnosis of PCNSL can be challenging. Non-invasive or minimally invasive tests such as ophthalmological evaluation and spinal fluid analysis may be useful, but the majority of patients require tumor biopsy for definitive diagnosis. Our knowledge concerning optimum treatment of PCNSL is fragmentary due to paucity of adequately sized trials. Most patients are now initially treated with high-dose-methotrexate-based chemotherapy alone, as the addition of whole-brain radiotherapy at standard doses has not been shown to increase survival and does increase the risk of neurological toxicity. Ongoing trials are addressing issues such as the roles of reduced-dose radiotherapy, the addition of the CD20 antibody rituximab to chemotherapy, high-dose chemotherapy followed by autologous stem cell transplantation, and maintenance therapy in the primary management of PCNSL.

Relapsed or refractory primary central nervous system lymphoma radiosurgery: Report of the International Gamma Knife Research Foundation

Stereotactic radiosurgery (SRS) can be used as part of multimodality management for patients with primary central nervous system lymphoma (PCNSL). The objective of this study is to evaluate outcomes of SRS for this disease. The International Gamma Knife Research Foundation identified 23 PCNSL patients who underwent SRS for either relapsed (intracerebral in-field or out-of-field tumor recurrences) or refractory disease from 1995-2014. All 23 patients presented with RPA Class I or II PCNSL, and were initially treated with a median of 7 cycles of methotrexate-based chemotherapy regimens (range, 3-26 cycles). Ten received prior whole brain radiation (WBRT) to a median dose of 43 Gy (range, 24-55 Gy). Sixteen presented with relapsed PCNSL, and seven presented with refractory disease. Twenty-three received 26 procedures of SRS. The median tumor volume was 4 cm³ (range, 0.1-26 cm³), and the median margin dose was 15 Gy (range, 8-20 Gy). Median follow-up from SRS was 11 months (interquartile range, 5.7-33.2 months). Twenty presented with treatment response to twenty-three tumors (12 complete, 11 partial). Fourteen patients relapsed or were refractory to salvage SRS, and local control was 95%, 91%, and 75% at 3, 6, and 12 months post SRS. Intracranial (in-field and out-of-field) and distant (systemic) PFS was 86%, 81%, and 55% at 3, 6, and 12 months post SRS. Toxicity of SRS was low, with one developing an adverse radiation effect requiring no additional intervention. Although methotrexate-based chemotherapy regimens with or without WBRT is the first-line management option for PCNSL, SRS may be used as an alternative option in properly selected patients with smaller relapsed or refractory PCNSL tumors.

Phase II Trial of Temsirolimus for Relapsed/Refractory Primary CNS Lymphoma

PURPOSE

In this phase II study (NCT00942747), temsirolimus was tested in patients with relapsed or refractory primary CNS lymphoma (PCNSL).

PATIENTS AND METHODS

Immunocompetent adults with histologically confirmed PCNSL after experiencing high-dose methotrexate-based chemotherapy failure who were not eligible for or had experienced high-dose chemotherapy with autologous stem-cell transplant failure were included. The first cohort (n = 6) received 25 mg temsirolimus intravenously once per week. All consecutive patients received 75 mg intravenously once per week.

RESULTS

Thirty-seven eligible patients (median age, 70 years) were included whose median time since their last treatment was 3.9 months (range, 0.1 to 14.6 months). Complete response was seen in five patients (13.5%), complete response unconfirmed in three (8%), and partial response in 12 (32.4%) for an overall response rate of 54%. Median progression-free survival was 2.1 months (95% CI, 1.1 to 3.0 months). The most frequent Common Toxicity Criteria ≥ 3° adverse event was hyperglycemia in 11 (29.7%) patients, thrombocytopenia in eight (21.6%), infection in seven (19%), anemia in four (10.8%), and rash in three (8.1%). Fourteen blood/CSF pairs were collected in nine patients (10 pairs in five patients in the 25-mg cohort and four pairs in four patients in the 75-mg cohort). The mean maximum blood concentration was 292 ng/mL for temsirolimus and 37.2 ng/mL for its metabolite sirolimus in the 25-mg cohort and 484 ng/mL and 91.1 ng/mL, respectively, in the 75-mg cohort. Temsirolimus CSF concentration was 2 ng/mL in one patient in the 75-mg cohort; in all others, no drug was found in their CSF.

CONCLUSION

Single-agent temsirolimus at a weekly dose of 75 mg was found to be active in relapsed/refractory patients with PCNSL; however, responses were usually short lived.

Topotecan combined with Ifosfamide, Etoposide, and L-asparaginase (TIEL) regimen improves outcomes in aggressive T-cell lymphoma

This study evaluated the efficacy and safety of a new regimen consisting of Topotecan, Ifosfamide, Etoposide, and L-asparaginase (TIEL) in treating aggressive T-cell lymphoma. Twenty-four patients were included in the research, eighteen males and six females. Half of the patients were in stages III and IV, and nearly half of them experienced failure of at least one regimen. Eleven were diagnosed as peripheral T-cell lymphoma (PTCL), five extranodal NK/T-cell lymphoma, non-specific, four angioimmunoblastic, and four anaplastic large-cell lymphoma (2 ALK positive). Patients were given 98 cycles of TIEL altogether. The responsive rate to TIEL was 76.9 % among 13 cases who received the regimen as the first-line treatment. Among 11 cases, TIEL was the second- or more-line treatment, the responsive rate was 63.6 %. The median PFS was 32.0 ± 21.0 (95 % CI 0-73.29) months. Median overall survival (OS) was not reached yet. Approximately 41.3 % of patients showed the third- to fourth-degree hematological side effects. Non-hematological toxicity included nausea, vomiting, diarrhea, and abnormal liver function. Among those patients received L-asparaginase, nine experienced mild abnormal coagulation function after 7 days of initiating chemotherapy, and no pancreatic injury was found. TIEL regimen is effective for aggressive T-cell lymphoma with controllable side effect and can be used for more patients.

Salvage therapy with bendamustine for methotrexate refractory recurrent primary CNS lymphoma: a retrospective case series

There is comparatively limited therapy for recurrent primary central nervous system lymphoma (PCNSL). Salvage therapies include re-challenge with high-dose methotrexate (HD-MTX), whole brain radiotherapy, temozolomide, topotecan and premetrexed. Bendamustine is a novel bifunctional alkylator with established activity in B cell systemic lymphomas but never previously evaluated in PCNSL. The objective of the current study was to assess response and toxicity of bendamustine in recurrent PCNSL following prior salvage therapy in a retrospective case series. Twelve adults [six males; six females: median age 59 years (range 43-74)] with HD-MTX refractory recurrent PCNSL were treated with bendamustine. All patients were treated at second recurrence following failure of prior salvage therapy. A cycle of bendamustine was defined as two consecutive days of treatment (100 mg/m(2)/day) administered once every 4 weeks (maximum number of cycles 6). Toxicities seen were Grade 2 (24 episodes in 10 patients) and 3 (10 episodes in 5 patients) only and included lymphopenia (8 patients), hyperglycemia (7 patients), fatigue (7 patients) and nausea (4 patients). The median number of cycles of therapy was 3.5 (range 1-6). Radiographic response was progressive disease in 5 (42%), stable disease in 1 (8%), partial response in 3 (25%) and complete response in 3 (25%). Median progression free survival (PFS) was 3.5 months (range 1-14 months) and 6-month PFS was 33 %. In this small retrospective series of select patients with recurrent PCNSL refractory to HD-MTX, bendamustine appears to have modest single agent activity with manageable toxicity. Confirmation in a larger series of similar patients is required.

Recent advances in treatment of primary central nervous system lymphoma

OPINION STATEMENT

Therapeutic options are limited in primary central nervous system lymphoma (PCNSL) with no uniform consensus on optimal management and few published, randomized trials. High-dose methotrexate in combination with other chemotherapeutic agents forms the mainstay of treatment. There hasn't been much progress beyond high-dose methotrexate in this disease, and although results from trials using high-dose chemotherapy and autologous stem-cell transplant seem promising, these need to be further validated. Moreover, the role of whole brain radiation in the upfront setting remains to be determined. However, international efforts in this direction are underway, with ongoing randomized trials in newly diagnosed PCNSL, more research on the molecular pathogenesis and biomarkers, and the use of novel agents in salvage therapy. There also is emphasis on quality of life parameters and neurocognitive status. Future treatment options should optimize high-efficacy rates while minimizing the risk of neurotoxicity.

Treatment outcome of relapsed/refractory primary central nervous system diffuse large B-cell lymphoma: a single-center experience of autologous stem cell transplantation

No salvage treatment strategy has been established for relapsed or refractory primary central nervous system lymphoma (PCNSL). We compared treatment outcomes of patients who underwent salvage chemotherapy with or without autologous stem cell transplantation (ASCT). We retrospectively analyzed PCNSL patients who were histologically diagnosed with diffuse large B-cell lymphoma. All patients relapsed after high-dose methotrexate (MTX)-based chemotherapy, or were refractory to high-dose MTX. Patients were treated with salvage chemotherapy, such as ICE/D (ifosfamide, carboplatin, etoposide, and dexamethasone) or high-dose MTX. High-dose chemotherapy containing thiotepa and busulfan followed by ASCT was performed if patients were eligible for ASCT after salvage treatment. Forty-five patients (35 relapsed and 10 refractory) received ICE/D or high-dose MTX. Despite the important difference that ICE/D was used predominantly for early relapsed or refractory patients, the two salvage treatments produced similar overall response rates [84.4 % (38/45) for ICE/D and 81.3 % (13/16) for high-dose MTX re-treatment]. Eighteen patients underwent ASCT, whereas 27 patients received salvage chemotherapy alone. The median progression-free survival of patients who underwent ASCT (19.5 months) was significantly better than that of patients who did not receive ASCT (6.7 months, P = 0.023). Multivariate analysis showed that refractoriness to initial treatment and no ASCT were significantly associated with poor survival outcome. Our study suggested that the combination of ifosfamide, carboplatin, etoposide, and dexamethasone may represent a feasible salvage treatment option for relapsed or refractory PCNSL, and that high-dose chemotherapy containing thiotepa and busulfan followed by ASCT may be effective for patients with a favorable toxicity profile.

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.

Diagnosis and treatment of primary CNS lymphoma

Primary CNS lymphoma (PCNSL) is a rare lymphoma that is confined to the CNS, with low tendency for systemic dissemination and a relatively aggressive course. Outcome in patients with PCNSL is often poor. Owing to its low incidence, current knowledge about optimal treatment of PCNSL is fragmentary. Chemotherapy regimens based on high-dose methotrexate are currently standard treatment for all patients with PCNSL who can tolerate such drugs. Whole-brain radiotherapy alone can lead to remission in up to 90% of patients, but often results in poor long-term disease control when given alone, and in delayed neurotoxicity when given after high-dose methotrexate. In this Review, we describe current approaches to diagnosis and treatment of PCNSL, and discuss novel therapeutic approaches that are currently in development, such as the use of rituximab and high-dose chemotherapy followed by autologous stem-cell transplantation. The possible use of intrathecal and intraventricular chemotherapy, optimal salvage treatment, and specific treatment approaches in elderly, paediatric and immunocompromised patients, are also considered.

Primary CNS lymphoma: a clinician's guide

Primary CNS lymphoma is a high malignant disease of the brain which can lead rapidly to death if diagnosis and/or the start of treatment is delayed. The age at time of diagnosis is a strong factor influencing prognosis so that in younger patients <65 years of age long-term survival may be achieved in a substantial percentage of patients, while in elderly patients long-term survival is seen much more rarely. First-line therapy consists of high-dose methotrexate-based (poly)chemotherapy. This review provides an overview of clinical presentation, steps to diagnosis, detailed information about current treatment concepts and specific information for particular clinical situations.

Salvage chemoimmunotherapy with rituximab, ifosfamide and etoposide (R-IE regimen) in patients with primary CNS lymphoma relapsed or refractory to high-dose methotrexate-based chemotherapy

Despite a high proportion of patients with primary CNS lymphoma (PCNSL) experiences failure after/during first-line treatment, a few studies focused on salvage therapy are available, often with disappointing results. Herein, we report feasibility and activity of a combination of rituximab, ifosfamide and etoposide (R-IE regimen) in a multicentre series of patients with PCNSL relapsed or refractory to high-dose methotrexate-based chemotherapy. We considered consecutive HIV-negative patients ≤75 years old with failed PCNSL treated with R-IE regimen (rituximab 375 mg/m(2) , day 0; ifosfamide 2 g/m(2) /day, days1-3; etoposide 250 mg/m(2) , day 1; four courses). Twenty-two patients (median age 60 years; range 39-72; male/female ratio: 1:4) received R-IE as second-line (n = 18) or third-line (n = 4) treatment. Eleven patients had refractory PCNSL, and 11 had relapsing disease. Twelve patients had been previously irradiated. Sixty (68%) of the 88 planned courses were actually delivered; only one patient interrupted R-IE because of toxicity. Grade 4 hematological toxicity was manageable; a single case of grade 4 non-hematological toxicity (transient hepatotoxicity) was recorded. Response was complete in six patients and partial in three (overall response rate = 41%; 95%CI: 21-61%). Seven patients were successfully referred to autologous peripheral blood stem cell collection; four responders were consolidated with high-dose chemotherapy supported by autologous stem cell transplant. At a median follow-up of 24 months, eight responders did not experience relapse, two of them died of neurological impairment while in remission. Six patients are alive, with a 2-year survival after relapse of 25 ± 9%. We concluded that R-IE is a feasible and active combination for patients with relapsed/refractory PCNSL. This regimen allows stem cell collection and successful consolidation with high-dose chemotherapy and autologous transplant.

Pathogenesis and management of primary CNS lymphoma

Primary CNS lymphoma (PCNSL), a rare variant of extranodal non-Hodgkin's lymphoma, may cause various neurological symptoms and signs. The best therapeutic strategy is still a matter of debate. High-dose methotrexate (HD-MTX) is the most active compound and should be used as the backbone for any chemotherapy applied. Several other chemotherapeutic drugs have been assessed in combination with HD-MTX, but no standard has yet been defined. Whole-brain radiotherapy is active against PCNSL, but typically does not confer long-lasting remission and is associated with significant neurotoxicity in many patients. The recently published G-PCNSL-SG1 trial has shown that consolidating whole-brain radiotherapy after HD-MTX-based chemotherapy does not prolong overall survival and may therefore be deferred. Combined systemic and intraventricular polychemotherapy, or high-dose chemotherapy followed by stem cell transplantation may offer cures to younger patients. Improving treatment regimens without adding significant (neuro-)toxicity should be the focus of ongoing and future studies.

Current and emerging pharmacotherapies for primary CNS lymphoma

Primary central nervous system lymphoma (PCNSL) constitutes a rare group of extranodal non-Hodgkin's lymphoma (NHL) primarily of B cell origin. It occurs in both immuno-competent and immune-compromised patients. High dose m ethotrexate (HD-MTX) based chemotherapy is the standard therapy. Chemotherapy with whole brain radiation therapy (WBRT) improves response rates and survival compared with WBRT alone. However, due to the increased risk for neurotoxicity with WBRT, recent studies have focused on using chemotherapy alone. Methotrexate based multi-agent chemotherapy without WBRT is associated with similar t reatment rates and survival compared with regimens that include WBRT although controlled trials have not been performed. Because of the low incidence of this disease, it is difficult to conduct randomized controlled trials. In this article we have discussed about the past, present and emerging treatment options in patients with PCNSL.

Long-term follow-up of high-dose chemotherapy with autologous stem-cell transplantation and response-adapted whole-brain radiotherapy for newly diagnosed primary CNS lymphoma: results of the multicenter Ostdeutsche Studiengruppe Hamatologie und Onkologie OSHO-53 phase II study

BACKGROUND

We previously reported the results of a phase II study for patients with newly diagnosed primary central nervous system lymphoma treated with autologous peripheral blood stem-cell transplantation (aPBSCT) and response-adapted whole-brain radiotherapy (WBRT). Now, we update the initial results.

PATIENTS AND METHODS

From 1999 to 2004, 23 patients received high-dose methotrexate. In case of at least partial remission, high-dose busulfan/thiotepa (HD-BuTT) followed by aPBSCT was carried out. Patients refractory to induction or without complete remission after HD-BuTT received WBRT. Eight patients still alive in 2011 were contacted and Mini-Mental State Examination (MMSE) and the European Organisation for Research and Treatment of Cancer quality-of-life questionnaire (QLQ)-C30 were carried out.

RESULTS

Of eight patients still alive, median follow-up is 116.9 months. Only one of nine irradiated patients is still alive with a severe neurologic deficit. In seven of eight patients treated with HD-BuTT, health condition and quality of life are excellent. MMSE and QLQ-C30 showed remarkably good results in patients who did not receive WBRT. All of them have a Karnofsky score of 90%-100%.

CONCLUSIONS

Follow-up shows an overall survival of 35%. In six of seven patients where WBRT could be avoided, no long-term neurotoxicity has been observed and all patients have an excellent quality of life.

Long-term survival of a child with refractory anaplastic large cell lymphoma following therapy with an antisense oligonucleotide, topotecan, and vinblastine

Anaplastic large cell lymphoma includes a subset of highly aggressive tumours and has a relapse rate of 30% at 2 years. Relapsed patients often have poor clinical outcome. The use of antisense oligonucleotides to down-regulate Bcl-2 protein can reverse chemotherapy resistance. The authors describe an 11-year-old boy with recurrent anaplastic large cell lymphoma who had received double high-dose chemotherapy followed by autologous haematopoietic stem-cell transplantation, had refractory disease and then had achieved long-term remission with the use of an antisense oligonucleotides in combination with vinblastine and topotecan.

Late relapse in primary central nervous system lymphoma: clonal persistence

Recurrence of primary central nervous system lymphoma (PCNSL) after initial diagnosis and treatment occurs within 2 years in most patients, and relapse after 5 years is rare. We evaluated late relapse in our PCNSL population. We identified 10 patients from our database of 378 patients (268 achieved a complete response and 230 had relapse) with PCNSL who had relapse ≥5 years after initial diagnosis. At initial diagnosis, their median age was 47 years; all patients had brain involvement and achieved a complete response to initial therapy (9 received high-dose methotrexate). Median time to first relapse was 7.4 years (range, 5.2-14.6 y). Eight patients had relapse in the brain, 1 had ocular relapse, and 1 had a systemic relapse. The histologic specimens at initial diagnosis and relapse were examined for clonal rearrangement in 3 patients; 1 had the identical clone at initial diagnosis and relapse 13.8 years later, and the other 2 were uninformative. All patients received salvage therapy (9 received systemic therapy and 1 received intraocular chemotherapy. Nine patients achieved a complete response to salvage therapy and 1 achieved a partial response. Four patients had relapse a second time. The median progression-free survival after first relapse was 31 months (range, 7.9-82.4). Late relapses accounted for 4% of all recurrences (10 of 230 patients) in our PCNSL population. Long-term persistence of the PCNSL clone was observed in one patient. Patients with late relapses have a good response to salvage therapy and prolonged survival.

Ocular relapse of primary brain lymphoma in immunocompetent patient, treated with intrathecal rituximab

Primary brain lymphoma is a rare variant of extranodal non-Hodgkin's B-cell lymphoma. In >90% of cases, this is diffuse large B-cell lymphoma with CD20 expression and is confined to the brain, meninges, spinal cord, and eyes. It accounts for fewer than 7% of primary brain tumors. Its incidence has been rising in recent years in immunocompetent patients in their fifth and sixth decades. The rate of relapse after initial therapy based on high-dose methotrexate and/or total brain irradiation is high. There is no consensus for treating relapse, which ranges from retreatment with high doses of methotrexate, polychemotherapy, high doses of chemotherapy backed up by autologous stem-cell transplant to intrathecal chemotherapy, with widely differing results. Given the lack of consensus and poor results, new therapy options have appeared, including immunotherapy with rituximab. At a systemic level, alongside chemotherapy, its results are very modest and limited due to the low concentration it reaches in cerebrospinal fluid (CSF). However, its intrathecal and intraventricular use, though only isolated cases have been reported, has provided promising results.

Primary central nervous system lymphoma

PURPOSE OF REVIEW

This review will summarize recent advances in the understanding and treatment of primary central nervous system lymphoma (PCNSL).

RECENT FINDINGS

The molecular and genetic characteristics that distinguish PCNSL are beginning to be elucidated. New tools such as flow cytometry and PET are improving the diagnosis and management of PCNSL. Although the current standard of care is high-dose methotrexate-based chemotherapy alone or in combination with whole brain radiotherapy, multiple questions remain regarding the optimal treatment of PCNSL, in general, and unusual variants of PCNSL.

SUMMARY

Although recent advances have improved our understanding of PCNSL, the need for additional collaborative research is critical.

Management of immunocompetent patients with primary central nervous system lymphoma

Primary central nervous system (CNS) lymphoma (PCNSL) is a non-Hodgkin lymphoma that arises within and is confined to the CNS. Recent data have suggested an increasing incidence in immunocompetent individuals, with a peak of incidence between 60 and 70 years of age. Patients with PCNSL present mostly with symptoms of increased intracranial pressure. The clinical management of these patients remains controversial, and the optimal treatment for patients with PCNSL has not yet been defined. Surgery, even if macroscopically radical, does not improve survival because of the multifocal and infiltrative nature of PCNSL; furthermore, the deep location of most of these tumors makes patients susceptible to serious and irreversible neurologic sequelae. Corticosteroids have a specific role in the treatment of patients with PCNSL, whose disease is sensitive to them as a chemotherapeutic agent. PCNSL is an extremely radiation-sensitive neoplasm; whole-brain radiation therapy plus corticosteroids was the first modality of treatment for patients with this neoplasm until 10 years ago, with a low cure rate and a high local recurrence rate. PCNSL is also a chemosensitive neoplasm; while the optimal choice, sequence, and combination of appropriate agents for efficacious treatment of patients with PCNSL has yet to be determined. An essential component of therapy must include an adequate drug delivery behind a normal blood-brain barrier. Methotrexate is the agent with the most proven activity in PCNSL. Combined-modality therapy has improved survival, but relapse is still common, and late neurologic toxicity is a significant complication, especially in older patients, who represent the majority of immunocompetent patients with PCNSL.

Primary central nervous system lymphoma: an update

PURPOSE OF REVIEW

The purpose of the present review is to present an overview of the recent findings in diagnostic procedures, treatment outcomes and biological advances in primary central nervous system lymphoma (PCNSL).

RECENT FINDINGS

Recent imaging techniques are helpful in the diagnosis of atypical presentations of PCNSL and are likely to represent useful tools for patient follow-up. Knowledge of the biology of PCNSL is still fragmentary, but an increasing amount of data support the biological specificity of this disease with the identification of specific molecular alterations in PCNSL and specific interactions of lymphoma cells with the CNS microenvironment. The origin of the malignant cell is still unknown. Improvement of the therapeutic results along with numerous phase II studies clearly highlight a few important issues that need to be unequivocally answered and stress the need for the development of multicentric comparative studies. Attempts to decrease treatment-related toxicity on the CNS without impacting the disease control are ongoing.

SUMMARY

The standard of care for PCNSL has definitively switched toward a curative objective. Considerable cooperative efforts are being made and will hopefully result in both a better understanding of the disease and significant therapeutic outcomes.

Therapeutic challenges in primary CNS lymphoma

Optimum treatment for patients with primary CNS lymphoma remains challenging because there have not been any large randomised clinical trials of this rare tumour. Drugs used in treating systemic non-Hodgkin lymphoma have mostly proven ineffective because of difficulties crossing the blood-brain barrier. The recognition of the efficacy of high-dose methotrexate was a substantial therapeutic breakthrough and further advances, such as the development of polychemotherapy regimens, have built on this. Whole-brain radiotherapy can consolidate response to chemotherapy, but the associated toxic effects of chemoradiation can be unacceptable. Other effective approaches include disruption of the blood-brain barrier and the use of high-dose chemotherapy. Recently, there have been attempts to optimise multi-drug chemotherapy regimens by focusing on improving survival and reducing toxic effects. A promising area of research is the incorporation of novel targeted drugs into standard treatment frameworks. In the future, greater cooperation between research groups should hopefully lead to further therapeutic advances.