Intensive chemotherapy and immunotherapy in patients with newly diagnosed primary CNS lymphoma: CALGB 50202 (Alliance 50202)

Methotrexate and temozolomide versus methotrexate, procarbazine, vincristine, and cytarabine for primary CNS lymphoma in an elderly population: an intergroup ANOCEF-GOELAMS randomised phase 2 trial

BACKGROUND

No standard chemotherapy regimen exists for primary CNS lymphoma, reflecting an absence of randomised studies. We prospectively tested two promising methotrexate-based regimens, one more intensive and a milder regimen, for primary CNS lymphoma in the elderly population, who account for most patients.

METHODS

In this open-label, randomised phase 2 trial, done in 13 French institutions, we enrolled immunocompetent patients who had neuroimaging and histologically confirmed newly diagnosed primary CNS lymphoma, were aged 60 years and older, and had a Karnofsky performance scale score of 40 or more. Participants were stratified by Karnofsky performance scale score (<60 vs ≥60) and treating institution and randomly assigned (1:1) to receive methotrexate (3·5 g/m(2)) with temozolomide (150 mg/m(2)) or methotrexate (3·5 g/m(2)), procarbazine (100 mg/m(2)), vincristine (1·4 mg/m(2)), and cytarabine (3 mg/m(2)). Neither regimen included radiotherapy; both included prophylactic G-CSF and corticosteroids. The primary endpoint was 1-year progression-free survival. Analysis was intent to treat, in a non-comparative phase 2 trial design. This study is registered with ClinicalTrials.gov, number NCT00503594.

FINDINGS

Between July 16, 2007, and March 25, 2010, 98 patients were enrolled, of whom 95 were randomly assigned and analysed; 48 to methotrexate with temozolomide and 47 to methotrexate, procarbazine, vincristine, and cytarabine. 1-year progression-free survival was 36% (95% CI 22-50) in the methotrexate, procarbazine, vincristine, and cytarabine group and 36% (22-50) in the methotrexate with temozolomide group; median progression-free survival was 9·5 months (95% CI 5·3-13·8) versus 6·1 months (3·8-11·9), respectively. Objective responses were noted in 82% (95% CI 68-92) of patients in the methotrexate, procarbazine, vincristine, and cytarabine group versus 71% (55-84) of patients in the methotrexate with temozolomide group. Median overall survival was 31 months (95% CI 12·2-35·8) in the methotrexate, procarbazine, vincristine, and cytarabine group and 14 months (8·1-28·4) in the methotrexate with temozolomide group. No differences were noted in toxic effects between the two groups. The most common grades 3 and 4 toxicities in both groups were liver dysfunction (21 [4%] in the the methotrexate and temozolomide group and 18 [38%] in the methotrexate, procarbazine, vincristine, and cytarabine group), lymphopenia (14 [29%] and 14 [30%]), and infection (six [13%] and seven [15%]). To date, 33 (69%) patients in the methotrexate and temozolomide group have died, versus 31 (55%) in the methotrexate, procarbazine, vincristine and cytarabine group. Quality-of-life evaluation (QLQ-C30 and BN20) showed improvements in most domains (p=0·01-0·0001) compared with baseline in both groups. Prospective neuropsychological testing showed no evidence of late neurotoxicity.

INTERPRETATION

In this study of two different methotrexate-based combination regimens in elderly patients, the efficacy endpoints tended to favour the methotrexate, procarbazine, vincristine, and cytarabine group. Both regimens were associated with similar, moderate toxicity, but quality of life improved with time, suggesting pursuing treatment in these poor prognosis patients is worthwhile. New alternatives are needed to improve response duration in this population.

FUNDING

Schering-Plough/Merck and French Government.

[Primary CNS lymphoma. Progress in the diagnostics and therapy]

BACKGROUND

Some important knowledge has recently been gained on primary central nervous system lymphomas (PCNSL) despite its rarity.

GOAL

This article summarizes the most relevant progress in the diagnostics and therapy of PCNSL and discusses future directions.

MATERIAL AND METHODS

Reference articles in the English language literature were studied with respect to future approaches in PCNSL.

RESULTS

New diagnostic methods in cerebrospinal fluid have been developed to facilitate lymphoma diagnosis; however, their value still has to be validated. A better immunohistological and molecular characterization of PCNSL will probably result in identification of new therapeutic targets. The only phase III trial for PCNSL completed so far did not demonstrate a survival advantage with whole brain irradiation after high-dose methotrexate (HDMTX)-based chemotherapy as compared to chemotherapy alone. The optimal primary chemotherapy has not yet been established due to a lack of results from randomized trials. Non-comparative studies suggest a superiority of combined polychemotherapy over HDMTX monotherapy. Future therapeutic developments are directed towards consolidation of HDMTX-based induction chemotherapy with noncross-resistant conventional chemotherapy or high-dose chemotherapy with autologous stem cell transplantation. An important goal of all therapies for PCNSL is to avoid delayed neurotoxicity.

DISCUSSION

Further improvement of diagnostics and well-designed comparative studies, including new drugs when possible are still needed to define the optimal management of this still frequently prognostically unfavorable disease.

Treatment of primary CNS lymphoma

In this issue of Blood, Omuro et al report the results of a phase 2 study for patients with newly diagnosed primary central nervous system lymphoma (PCNSL) using induction immunochemotherapy (rituximab, high-dose methotrexate [MTX], vincristine, procarbazine) followed by a novel consolidation high-dose chemotherapy (thiotepa, busulfan, cyclophosphamide) and autologous stem cell transplantation (HDC-ASCT).

MYC protein expression is associated with poor prognosis in primary diffuse large B-cell lymphoma of the central nervous system

MYC and BCL2 gene translocations and protein expression have recently demonstrated to be of prognostic significance in systemic diffuse large B-cell lymphoma (DLBCL). However, their role in primary central nervous system DLBCL (CNS-DLBCL) prognosis has been scarcely analyzed. We studied the immunophenotype, the status of the MYC, BCL2, and BCL6 genes and the clinical features of a series of 42 CNS-DLBCL and evaluated their prognostic significance. We found high MYC protein expression in 43% of cases, and this was associated with lower overall survival (OS). Cases with concurrent expression of MYC and BCL2 showed a lower OS, although the difference did not reach statistical significance. Translocations involving the MYC or BCL2 genes were not detected. The BCL6 gene was frequently translocated, but was unrelated to survival. We conclude that MYC protein expression detected by immunohistochemistry identifies a CNS-DLBCL subset with worse prognosis and may contribute to a more accurate risk stratification of CNS-DLBCL patients.

Nivolumab and ipilimumab versus ipilimumab in untreated melanoma

BACKGROUND

In a phase 1 dose-escalation study, combined inhibition of T-cell checkpoint pathways by nivolumab and ipilimumab was associated with a high rate of objective response, including complete responses, among patients with advanced melanoma.

METHODS

In this double-blind study involving 142 patients with metastatic melanoma who had not previously received treatment, we randomly assigned patients in a 2:1 ratio to receive ipilimumab (3 mg per kilogram of body weight) combined with either nivolumab (1 mg per kilogram) or placebo once every 3 weeks for four doses, followed by nivolumab (3 mg per kilogram) or placebo every 2 weeks until the occurrence of disease progression or unacceptable toxic effects. The primary end point was the rate of investigator-assessed, confirmed objective response among patients with BRAF V600 wild-type tumors.

RESULTS

Among patients with BRAF wild-type tumors, the rate of confirmed objective response was 61% (44 of 72 patients) in the group that received both ipilimumab and nivolumab (combination group) versus 11% (4 of 37 patients) in the group that received ipilimumab and placebo (ipilimumab-monotherapy group) (P<0.001), with complete responses reported in 16 patients (22%) in the combination group and no patients in the ipilimumab-monotherapy group. The median duration of response was not reached in either group. The median progression-free survival was not reached with the combination therapy and was 4.4 months with ipilimumab monotherapy (hazard ratio associated with combination therapy as compared with ipilimumab monotherapy for disease progression or death, 0.40; 95% confidence interval, 0.23 to 0.68; P<0.001). Similar results for response rate and progression-free survival were observed in 33 patients with BRAF mutation-positive tumors. Drug-related adverse events of grade 3 or 4 were reported in 54% of the patients who received the combination therapy as compared with 24% of the patients who received ipilimumab monotherapy. Select adverse events with potential immunologic causes were consistent with those in a phase 1 study, and most of these events resolved with immune-modulating medication.

CONCLUSIONS

The objective-response rate and the progression-free survival among patients with advanced melanoma who had not previously received treatment were significantly greater with nivolumab combined with ipilimumab than with ipilimumab monotherapy. Combination therapy had an acceptable safety profile. (Funded by Bristol-Myers Squibb; ClinicalTrials.gov number, NCT01927419.).

Stereotactic radiosurgery in combination with up-front high-dose methotrexate as a first-line treatment for newly diagnosed primary central nervous system lymphoma

The efficacy of stereotactic radiosurgery (SRS) instead of whole brain radiotherapy (WBRT) following high-dose methotrexate (HD-MTX) for primary central nervous system lymphoma (PCNSL) is unclear. To clarify whether SRS in combination with up-front HD-MTX supplements the effect of HD-MTX in remaining or refractory lesions after initial HD-MTX treatment. The authors conducted a retrospective review for newly diagnosed PCNSL patients who underwent SRS after HD-MTX as a first-line treatment. The local control (LC), the progression-free survival (PFS), the recurrence patterns, the salvage treatments, the overall survival (OS), the Karnofsky Performance Status (KPS), the activities of daily living (ADL) were analyzed as well as radiosurgical parameters. Twenty patients underwent SRS for 51 lesions with the median volume of 0.45 cm(3). The median age at SRS was 67 (range 37-82). The median KPS at SRS was 90. The LC rate at 2 years was 86.0 %, the median PFS after SRS was 17 months, necessitating additional SRS and chemotherapy. The median OS was 52 months. No significant side effects related to SRS were observed. During follow-up period, the good ADL preservation was achieved for 13 months from SRS. Patients with KPS ≥ 90 at SRS demonstrated longer ADL preservation (32 months from SRS). SRS following up-front HD-MTX without WBRT provided excellent LC, acceptable OS and the long ADL preservation period. These benefits may be more emphasized especially in patients with good KPS, but should be validated in a large patient population.

Prognostic impact of B-cell lymphoma 6 in primary CNS lymphoma

BACKGROUND

We investigated the prognostic significance of B-cell differentiation status and common B-cell differentiation markers in a post hoc analysis of 119 patients with primary CNS lymphoma (PCNSL) homogeneously receiving high-dose methotrexate (HDMTX)-based chemotherapy within the prospective G-PCNSL-SG1 trial.

METHODS

We evaluated protein expression of B-cell lymphoma 2 (BCL2), BCL6, CD10, and multiple myeloma oncogene 1/interferon regulatory factor 4 (MUM1/IRF4) by immunohistochemistry and analyzed the association with survival.

RESULTS

The median follow-up of all patients was 67.5 months. Median progression-free survival (PFS) was 10.61 months (95% CI: 4.23-17.00). Median overall survival (OS) was 28.85 months (95% CI: 17.96-39.73). Eighty-nine tumors expressed BCL2 (92.7%), 24 (20.5%) expressed CD10, 60 (54.1%) expressed BCL6, and 87 (79.0%) expressed MUM1/IRF4. On the basis of the Hans algorithm, 80 tumors (73.4%) were classified to the non-germinal center B group, suggesting a post-germinal center origin of PCNSL. Expression of BCL6 (cutoff point 30%), but none of the other markers, was associated with shorter PFS (P = .047) and OS (P = .035). On multivariate analysis, BCL6 expression was associated with shorter PFS (hazard ratio: 1.95, 95% CI: 1.22-3.12, P = .005) but not OS (hazard ratio: 1.85, 95% CI: 0.71-4.80, P = .21). Classification according to Hans algorithm and expression status of the single B-cell markers BCL2, CD10, and MUM1/IRF4 did not correlate with prognosis.

CONCLUSION

The findings are limited by the fact that only 23% of all G-PCNSL-SG1 patients could be included in the analysis. If validated in an independent cohort, BCL6 may assume clinical relevance as an unfavorable prognostic biomarker in PCNSL.

First-line treatment and outcome of elderly patients with primary central nervous system lymphoma (PCNSL)--a systematic review and individual patient data meta-analysis

BACKGROUND

To investigate prognosis and effects of first-line therapy in elderly primary central nervous system lymphoma (PCNSL) patients.

PATIENTS AND METHODS

A systematic review of studies about first-line therapy in immunocompetent patients ≥60 years with PCNSL until 2014 and a meta-analysis of individual patient data from eligible studies and international collaborators were carried out.

RESULTS

We identified 20 eligible studies; from 13 studies, we obtained individual data of 405 patients, which were pooled with data of 378 additional patients (N = 783). Median age and Karnofsky Performance Score (KPS) was 68 years (range: 60-90 years) and 60% (range: 10%-100%), respectively. Treatments varied greatly, 573 (73%) patients received high-dose methotrexate (HD-MTX)-based therapy. A total of 276 patients received whole-brain radiotherapy (median 36 Gy, range 28.5-70 Gy). KPS ≥ 70% was the strongest prognostic factor for mortality [hazard ratio (HR) 0.50, 95% confidence interval (CI) 0.41-0.62]. After a median follow-up of 40 months, HD-MTX-based therapy was associated with improved survival (HR 0.70, 95% CI 0.53-0.93). There was no difference between HD-MTX plus oral chemotherapy and more aggressive HD-MTX-based therapies (HR 1.39, 95% CI 0.90-2.15). Radiotherapy was associated with an improved survival, but correlated with an increased risk for neurological side-effects (odds ratio 5.23, 95% CI 2.33-11.74).

CONCLUSIONS

Elderly PCNSL patients benefit from HD-MTX-based therapy, especially if combined with oral alkylating agents. More aggressive HD-MTX protocols do not seem to improve outcome. WBRT may improve outcome, but is associated with increased risk for neurological side-effects. Prospective trials for elderly PCNSL patients are warranted.

R-MPV followed by high-dose chemotherapy with TBC and autologous stem-cell transplant for newly diagnosed primary CNS lymphoma

High-dose methotrexate-based chemotherapy is the mainstay of treatment of primary central nervous system lymphoma (PCNSL), but relapses remain frequent. High-dose chemotherapy (HDC) with autologous stem-cell transplant (ASCT) may provide an alternative to address chemoresistance and overcome the blood-brain barrier. In this single-center phase-2 study, newly diagnosed PCNSL patients received 5 to 7 cycles of chemotherapy with rituximab, methotrexate (3.5 g/m(2)), procarbazine, and vincristine (R-MPV). Those with a complete or partial response proceeded with consolidation HDC with thiotepa, cyclophosphamide, and busulfan, followed by ASCT and no radiotherapy. Primary end point was 1-year progression-free survival (PFS), N = 32. Median age was 57, and median Karnofsky performance status 80. Following R-MPV, objective response rate was 97%, and 26 (81%) patients proceeded with HDC-ASCT. Among all patients, median PFS and overall survival (OS) were not reached (median follow-up: 45 months). Two-year PFS was 79% (95% confidence interval [CI], 58-90), with no events observed beyond 2 years. Two-year OS was 81% (95% CI, 63-91). In transplanted patients, 2-year PFS and OS were 81%. There were 3 treatment-related deaths. Prospective neuropsychological evaluations suggested relatively stable cognitive functions posttransplant. In conclusion, this treatment was associated with excellent disease control and survival, an acceptable toxicity profile, and no evidence of neurotoxicity thus far. This trial was registered at www.clinicaltrials.gov as NCT00596154.

Trial Watch: Radioimmunotherapy for oncological indications

During the past two decades, it has become increasingly clear that the antineoplastic effects of radiation therapy do not simply reflect the ability of X-, β- and γ-rays to damage transformed cells and directly cause their permanent proliferative arrest or demise, but also involve cancer cell-extrinsic mechanisms. Indeed, among other activities, radiotherapy has been shown to favor the establishment of tumor-specific immune responses that operate systemically, underpinning the so-called 'out-of-field' or 'abscopal' effect. Thus, ionizing rays appear to elicit immunogenic cell death, a functionally peculiar variant of apoptosis associated with the emission of a particularly immunostimulatory combination of damage-associated molecular patterns. In line with this notion, radiation therapy fosters, and thus exacerbates, the antineoplastic effects of various treatment modalities, including surgery, chemotherapy and various immunotherapeutic agents. Here, we summarize recent advances in the use of ionizing rays as a means to induce or potentiate therapeutically relevant anticancer immune responses. In addition, we present clinical trials initiated during the past 12 months to test the actual benefit of radioimmunotherapy in cancer patients.

Primary central nervous system lymphoma: current state of anti-CD20 therapy and appraisal of reported response criteria

Primary central nervous system lymphoma (PCNSL) is an aggressive non-Hodgkin's lymphoma which is confined to the central nervous system and may also affect intraocular structures. Despite high initial rates of response to methotrexate-based chemotherapy, more than 50% of patients will experience relapse and about 10% have disease that is refractory to chemotherapy. Outcome in patients who fail treatment is very poor, and therefore new therapeutic approaches that may increase the rate of complete response and the proportion of durable remission are sought. Based on the pivotal role that anti-CD20 therapy now plays in the treatment outcome of aggressive systemic B-cell lymphomas, a similar approach is commonly being adapted for PCNSL despite the lack of evidence for its effectiveness. This review examines the current status and level of evidence for the use of monoclonal antibodies against the CD20 surface antigen, which is present on normal and malignant B-cells in PCNSL. The review covers both systemic and local (intracerebrospinal fluid or intravitreal) administration of CD20 monoclonal antibodies in PCNSL. In addition, it scrutinizes the response criteria commonly reported for evaluation of treatment outcome. The importance of differentiating unconfirmed complete response from partial response is outlined and the lack of consensus on response criteria for atypical imaging presentations of PCNSL is delineated.

MYC protein expression in primary diffuse large B-cell lymphoma of the central nervous system

Primary diffuse large B-cell lymphoma of the central nervous system (CNS DLBCL) is a rare, aggressive subtype of DLBCL, the biology of which is poorly understood. Recent studies have suggested a prognostic role of MYC protein expression in systemic DLBCL, but little is known about the frequency and significance of MYC protein expression in CNS DLBCL. Hence, we investigated MYC protein expression profiles of CNS DLBCL and assessed the relationship between MYC expression and a variety of histopathologic, immunophenotypic, genetic, and clinical features. Fifty-nine CNS DLBCL diagnosed at our institution over the past 13 years were evaluated. The majority of cases (80%) showed centroblastic morphology, and 12 (20%) displayed a perivascular pattern of infiltration. According to the Hans criteria, 41 (69%) cases had a non-germinal center B-cell and 18 (31%) had a germinal center B-cell cell-of-origin (COO) phenotype. Mean MYC protein expression was 50% (median: 50%, range: 10-80%). Forty-three cases (73%) showed MYC overexpression (≥ 40%), and 35 (60%) showed MYC/BCL2 coexpression. MYC overexpression was seen in the single case harboring MYC translocation and in the cases showing increased copies of MYC (27%); however, no significant difference in mean MYC expression was seen between groups harboring or lacking MYC aberrations. In our series, age was associated with a significantly increased risk of death, and the perivascular pattern of infiltration was associated with a significantly increased risk of disease progression. Neither MYC expression (with or without BCL2 coexpression) nor other variables, including COO subtype were predictive of clinical outcome. Our findings indicate that the proportion of CNS DLBCL overexpressing MYC is higher compared to systemic DLBCL, and MYC overexpression appears to be independent of genetic MYC abnormalities. Thus, MYC expression and other immunophenotypic markers used for prognostication of systemic DLBCL might not apply to CNS DLBCL due to differences in disease biology.

Successful change of treatment strategy in elderly patients with primary central nervous system lymphoma by de-escalating induction and introducing temozolomide maintenance: results from a phase II study by the Nordic Lymphoma Group

The Nordic Lymphoma Group has conducted a phase ll trial in newly diagnosed primary central nervous system lymphoma patients applying an age-adjusted multi-agent immunochemotherapy regimen, which in elderly patients included temozolomide maintenance treatment. Patients aged 18-75 years were eligible. Thirty-nine patients aged 18-65 years and 27 patients aged 66-75 years were enrolled. The median age of the two age groups was 55 and 70 years, respectively. The overall response rate was 73.8% for the entire cohort: 69.9% in the younger and 80.8% in the elderly subgroup. With a median follow up of 22 months, the 2-year overall survival probability was 60.7% in patients aged 65 years or under and 55.6% in patients aged over 65 years (P=0.40). The estimated progression-free survival at two years was 33.1% (95%CI: 19.1%-47.9%) in patients aged under 65 years and 44.4% (95%CI: 25.6%-61.8%) in the elderly subgroup (P=0.74). Median duration of response was ten months in the younger subgroup, and not reached in the elderly patient subgroup (P=0.33). Four patients aged 64-75 years (6%) died from treatment-related complications. Survival in the two age groups was similar despite a de-escalation of induction treatment in patients aged over 65 years. Duration of response in elderly patients receiving maintenance temozolomide was longer than in the younger age subgroup. While toxicity during induction is still of concern, especially in the elderly patients, we conclude from these data that de-escalation of induction therapy in elderly primary central nervous system lymphoma patients followed by maintenance treatment seems to be a promising treatment strategy. (clinicaltrials.gov identifier:01458730).

[Primary central nervous lymphoma: what is the role for radiotherapy?]

Primary central nervous system lymphoma is a rare extranodal form of non-Hodgkin lymphoma with an aggressive course and unsatisfactory outcome. Historically, whole-brain radiotherapy was the sole treatment for patients with primary central nervous system lymphoma, with high response rates but typically, this did not result in long-lasting remissions. The addition of high-dose methotrexate-based chemotherapy regimens to whole-brain radiotherapy has significantly improved patients' outcome, but has resulted in a higher incidence of late neurotoxicity, particularly in elderly patients. To date, the role of consolidation radiotherapy is controversial, and some investigators have developed alternative strategies aiming at avoiding immediate irradiation or using a reduced radiotherapy dose to the whole-brain with promising results.

A phase 1 dose escalation study of idarubicin combined with methotrexate, vindesine, and prednisolone for untreated elderly patients with primary central nervous system lymphoma. The GOELAMS LCP 99 trial

Treatment of primary central nervous system lymphoma (PCNSL) in elderly patients remains unsatisfactory. To develop a new high-dose methotrexate (HD-MTX)-based regimen including idarubicin, a phase 1 multicenter dose escalation study was conducted to determine the maximum-tolerated dose (MTD) of idarubicin. Thirty-five immunocompetent patients with PCNSL were enrolled. The median age was 65 years (range, 60-70 years). MTX and vindesine (VDS) were given at the fixed dose of 3 g/m(2) (6-hr intravenous [IV]) and 3 mg/m(2) IV on day 1, respectively. Prednisolone (PRED) was given at the fixed dose of 60 mg/m(2) (IV or orally) on days 1-5. Idarubicin was escalated in increments of 2 mg/m(2) with doses ranging from 12-18 mg/m(2) IV on day 1. Treatment was repeated three times every 3 weeks. Dose-limiting toxicity (DLT) was defined as grade 4 neutropenia for more than 7 days, thrombocytopenia grade 4 or nonhaematological toxicity more than grade 2. The MTD of idarubicin was reached at 16 mg/m(2) . At this level, the main haematological toxicities were thrombocytopenia grade 4: 5% and neutropenia grade 3 or 4 (52%); the main nonhaematological toxicities were grade 3 or 4 infectious disease (5%) and grade 2 renal failure (9%). For the study population, median overall and progression-free survival were 19 and 13 months, respectively. Our study suggests that the MTD of idarubicin in combination with HD-MTX, VDS, and PRED, should be 16 mg/m(2) . Further studies will be necessary to challenge a standard treatment in elderly patients with PCNSL.

Consolidative autologous hematopoietic stem-cell transplantation in first remission for non-Hodgkin lymphoma: current indications and future perspective

The non-Hodgkin lymphomas (NHLs) are a heterogeneous group of diseases with variable clinical outcomes. Autologous hematopoietic stem-cell transplantation (ASCT) as frontline, consolidative therapy has been evaluated based upon histological subtype of NHL. In this review, we summarize the major clinical trials guiding the use of frontline ASCT in NHL. With the constantly changing landscape of upfront therapy and multiple promising novel agents, the ability to conduct randomized trials to evaluate the benefit of consolidative ASCT is not only challenging but may be considered by some an inept utilization of resources. Our recommendation for consolidative ASCT is based on analyzing the current available data.

Phase 2 trial of high-dose rituximab with high-dose cytarabine mobilization therapy and high-dose thiotepa, busulfan, and cyclophosphamide autologous stem cell transplantation in patients with central nervous system involvement by non-Hodgkin lymphoma

BACKGROUND

High-dose thiotepa, busulfan, and cyclophosphamide (TBC) with autologous stem cell transplantation (ASCT) has been used in patients with central nervous system (CNS) involvement by non-Hodgkin lymphoma (NHL). Despite limited penetration into the CNS, rituximab is active in primary CNS NHL. Therefore, high-dose rituximab was combined with TBC for ASCT in patients with CNS NHL.

METHODS

A single-arm phase 2 trial using high-dose rituximab with cytarabine for stem cell mobilization followed by high-dose rituximab combined with thiotepa, busulfan, and cyclophosphamide (R-TBC) for ASCT was conducted. Doses of rituximab at 1000 mg/m(2) were given on days 1 and 8 of mobilization and on days -9 and -2 of TBC. The primary endpoint was efficacy.

RESULTS

Thirty patients were enrolled. Eighteen patients had primary CNS NHL (12 with complete remission (CR)/first partial remission (PR1) and 6 with CR/PR2), and 12 patients had secondary CNS lymphoma (5 with CR/PR1 and 7 with CR/PR2 or beyond). All patients were in partial or complete remission. Twenty-nine patients proceeded to R-TBC ASCT. Two patients developed significant neurotoxicity. The 100-day nonrelapse mortality rate was 0%, and 1 patient died because of nonrelapse causes 5 months after ASCT. For all patients, at a median follow-up of 24 months (range, 12-40 months), the estimated 2-year progression-free survival rate was 81% (95% confidence interval, 59%-92%), and the 2-year overall survival rate was 93% (95% confidence interval, 76%-98%). There were no relapses or deaths among the 18 patients with primary CNS lymphoma.

CONCLUSIONS

For patients with CNS involvement by B-cell NHL and especially for patients with primary CNS NHL, R-TBC ASCT shows encouraging activity and merits further study.

Upfront autologous stem-cell transplantation with melphalan, cyclophosphamide, etoposide, and dexamethasone (LEED) in patients with newly diagnosed primary central nervous system lymphoma

Treatment of primary central nervous system lymphoma (PCNSL) improved in recent years. However, the high neurotoxicity and low survival rates associated with this condition remain unresolved. We report 13 consecutive patients with PCNSL for whom upfront melphalan, cyclophosphamide, etoposide, and dexamethasone (known as LEED) followed by autologous stem-cell transplantation (ASCT) was planned at the Anjo Kosei Hospital. All patients were pathologically diagnosed with diffuse large B-cell lymphoma and were negative for human immunodeficiency virus. All patients were to receive three cycles of high-dose methotrexate-based induction chemotherapy, two cycles of high-dose AraC-based chemotherapy, and LEED followed by ASCT. All 13 patients achieved a partial response, and the 3-year overall survival (OS) rate was 76.2 %. Seven of the 13 patients were alive at the last follow-up, without any adverse events, including neurotoxicity. Six of the 13 (46.2 %) patients underwent ASCT and the 3-year OS rate was 80.0 %. Although this study included only a limited number of patients, these preliminary signs of efficacy and tolerability merit further consideration. To make further improvements in survival, the rate of patients undergoing ASCT should be increased. Other prospective studies involving greater numbers of patients are required to confirm these findings.

Progress in central nervous system lymphomas

Until recently, primary central nervous system lymphoma (PCNSL) was associated with a uniformly dismal prognosis. It is now reasonable to anticipate long-term survival and possibly cure for a significant proportion of patients diagnosed with PCNSL. Accumulated data generated over the past 10 years has provided evidence that long-term progression-free survival (PFS) can reproducibly be attained in a significant fraction of PCNSL patients that receive dose-intensive chemotherapy consolidation, without whole brain radiotherapy. One consolidative regimen that has reproducibly demonstrated promise is the combination of infusional etoposide plus high-dose cytarabine (EA), administered in first complete remission after methotrexate, temozolomide and rituximab-based induction. Given evolving principles of management and the mounting evidence for reproducible improvements in survival rates in prospective clinical series, our goal in this review is to highlight and update principles in diagnosis, staging and management as well as to review data regarding the pathogenesis of central nervous system lymphomas, information that is likely to constitute a basis for the implementation of novel therapies that are requisite for further progress in this unique phenotype of non-Hodgkin lymphoma.

Clinical outcomes of patients with newly diagnosed primary central nervous system lymphoma are comparable on treatment with high-dose methotrexate plus temozolomide and with high-dose methotrexate plus cytarabine: a single-institution experience

The role of temozolomide in untreated PCNSL patients has not yet been clearly defined. The purpose of this study was to compare the efficacy and toxicity of MT and MC chemotherapy in this population. A total of 41 consecutive patients were enrolled from March 2001 to July 2011. The ORR and CRR for MT vs. MC were 70% vs. 61.9% and 45% vs. 38.1% on ITT basis, (p = NS); 73.7% vs. 68.4% and 47.4% vs. 42.1% on PP basis, respectively (p = NS). Grade 3-4 hematological toxicities were more common in MC than in MT group (85.7% vs. 15%, p = 0.0001). One treatment-related death was observed in each group. The 5-year PFS and OS of MT (36% and 62.2%) were comparable to MC (32.6% and 46.7%), (p = NS). In summary, our preliminary results suggest that MT combination may be a simplified and effective regimen comparable to MC for newly diagnosed PCNSL.

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.

LMO2 and BCL6 are associated with improved survival in primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is an aggressive sub-variant of non-Hodgkin lymphoma (NHL) with morphological similarities to diffuse large B-cell lymphoma (DLBCL). While methotrexate (MTX)-based therapies have improved patient survival, the disease remains incurable in most cases and its pathogenesis is poorly understood. We evaluated 69 cases of PCNSL for the expression of HGAL (also known as GCSAM), LMO2 and BCL6 - genes associated with DLBCL prognosis and pathobiology, and analysed their correlation to survival in 49 PCNSL patients receiving MTX-based therapy. We demonstrate that PCNSL expresses LMO2, HGAL(also known as GCSAM) and BCL6 proteins in 52%, 65% and 56% of tumours, respectively. BCL6 protein expression was associated with longer progression-free survival (P = 0·006) and overall survival (OS, P = 0·05), while expression of LMO2 protein was associated with longer OS (P = 0·027). Further research is needed to elucidate the function of BCL6 and LMO2 in PCNSL.

Harnessing the immune system to provide long-term survival in patients with melanoma and other solid tumors

Accumulating data from patients treated with checkpoint inhibitors and other immunomodulatory agents indicate that harnessing the power of the immune system is integral to achieve improve long-term cancer containment rates and prolong patient survival. Due to their mechanism of action, immunotherapeutic approaches have the potential to be effective against almost every tumor type. Durable responses to immunotherapy and prolonged patient survival have indeed been documented in individuals with melanoma, as well as kidney and lung cancer. These advances call for the re-evaluation of how clinical benefit is measured in an era in which long-term tumor control and survival are achievable treatment goals.

Low-dose whole brain radiotherapy combined with radiosurgery for primary CNS lymphoma achieving partial response to induction methotrexate-based chemotherapy

PURPOSE

For patients with primary CNS lymphoma who achieve complete response (CR) after induction methotrexate-based chemotherapy with rituximab, low-dose whole brain radiation therapy (LD-WBRT) appears effective and is well tolerated. For patients who respond to induction methotrexate-based chemotherapy with or without rituximab but have unifocal residual disease less than 3 cm in size, we hypothesized that LD-WBRT combined with radiosurgery would be effective at controlling residual disease and well tolerated.

METHODS

Four adult patients with primary CNS lymphoma with a favorable response to induction chemotherapy but had residual disease less than 3 cm were identified. Induction chemotherapy consisted of methotrexate with or without additional agents including rituximab. LD-WBRT comprised 2340 cGy in 13 fractions. This was immediately preceded or followed by a single radiosurgery treatment of 12 12.5 Gy to the focus of residual disease defined on contrast enhanced T1 weighted MRI.

RESULTS

The median follow-up was 17.1 months (range 10-23 months). All patients had residual disease after induction chemotherapy but achieved complete response (CR) following LD-WBRT and radiosurgery. Three patients remained free of disease. One patient developed distant brain recurrence 12 months after radiation but remained alive at last follow-up (17 months). No treatment-related neurotoxicity was observed.

CONCLUSIONS

The combination of induction methotrexate-based chemotherapy with or without rituximab, LD-WBRT and radiosurgery appears effective and well tolerated in patients with primary CNS lymphoma who achieve a partial response (PR) to chemotherapy with minimal residual disease. Longer follow-up and larger patient numbers are clearly needed for confirmation.

Beyond high-dose methotrexate and brain radiotherapy: novel targets and agents for primary CNS lymphoma

BACKGROUND

While there has been significant progress in outcomes for patients diagnosed with primary central nervous system (CNS) lymphoma (PCNSL), survival rates will likely plateau with the current armamentarium of agents used to treat these patients. Moreover, given that PCNSL increasingly impacts an older population, a significant proportion of patients are not eligible for intensive therapies such as high-dose chemotherapy or whole-brain radiation. There is a need for the development of novel agents, which target key survival pathways in order to continue to make progress in this disease.

PATIENTS AND METHODS

We reviewed the key molecular pathways and genomic aberrations in PCNSL in order to identify candidate targets. We focused on molecules and pathways that have been identified and confirmed by more than one investigator or methodology.

RESULTS

While PCNSL tumors usually express a BCL6+, MUM1+ 'activated, germinal center' immunophenotype, they exhibit multiple shared genetic properties with ABC-type diffuse large B-cell lymphomas. Candidate targets and pathways include NFkB, the B-cell receptor, the JAK/STAT pathway, IRF4, BCL-6 as well as PIM kinases. Elements of the tumor microenvironment that may be exploited therapeutically include chemokine pathways, as well as macrophage and T-cell responses.

CONCLUSIONS

There is a significant need for developing novel therapies in PCNSL, given that an increasing proportion of patients are not eligible for high-dose chemotherapy and brain radiation is associated with detrimental cognitive side-effects. We provide an overview of potential drug targets and novel agents that may be integrated with existing strategies in order to make further progress in this disease.

How I treat CNS lymphomas

The pathogenesis of primary and secondary central nervous system (CNS) lymphoma poses a unique set of diagnostic, prognostic, and therapeutic challenges. During the past 10 years, there has been significant progress in the elucidation of the molecular properties of CNS lymphomas and their microenvironment, as well as evolution in the development of novel treatment strategies. Although a CNS lymphoma diagnosis was once assumed to be uniformly associated with a dismal prognosis, it is now reasonable to anticipate long-term survival, and possibly a cure, for a significant fraction of CNS lymphoma patients. The pathogenesis of CNS lymphomas affects multiple compartments within the neuroaxis, and proper treatment of the CNS lymphoma patient requires a multidisciplinary team with expertise not only in hematology/oncology but also in neurology, neuroradiology, neurosurgery, clinical neuropsychology, ophthalmology, pathology, and radiation oncology. Given the evolving principles of management and the evidence for improvements in survival, our goal is to provide an overview of current knowledge regarding the pathogenesis of CNS lymphomas and to highlight promising strategies that we believe to be most effective in establishing diagnosis, staging, and therapeutic management.