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

Pilot Study of High-Dose Pemetrexed in Patients with Progressive Chordoma

PURPOSE

Chordomas are ultrarare tumors of the axial spine and skull-base without approved systemic therapy. Most chordomas have negative expression of thymidylate synthase (TS), suggesting a potential for responding to the antifolate agent pemetrexed, which inhibits TS and other enzymes involved in nucleotide biosynthesis. We evaluated the therapeutic activity and safety of high-dose pemetrexed in progressive chordoma.

PATIENTS AND METHODS

Adult patients with previously treated, progressive chordoma participated in an open-label, single-institution, single-arm, pilot clinical trial of intravenous pemetrexed 900 mg/m2 every 3 weeks and supportive medications of folic acid, vitamin B12, and dexamethasone. The primary endpoint was objective response rate according to RECIST v1.1. Secondary endpoints included adverse events, progression-free survival (PFS), tumor molecular profiles, and alterations in tissue and blood-based biomarkers.

RESULTS

Fifteen patients were enrolled and the median number of doses administered was 15 (range, 4-31). One patient discontinued treatment due to psychosocial issues after four cycles and one contracted COVID-19 after 13 cycles. Of the 14 response-evaluable patients, 2 (14%) achieved a partial response and 10 (71%) demonstrated stable disease. Median PFS was 10.5 months (95% confidence interval: 9 months-undetermined) and 6-month PFS was 67%. Adverse events were expected and relatively mild, with one grade 3 creatinine increased, and one each of grade 3 and 4 lymphopenia. No grade 5 adverse events, unexpected toxicities, or dose-limiting toxicities were observed. Several patients reported clinical improvement in disease-related symptoms.

CONCLUSIONS

High-dose pemetrexed appears tolerable and shows objective antitumor activity in patients with chordoma. Phase II studies of high-dose pemetrexed are warranted.

Pemetrexed Plus Lenalidomide for Relapsed/Refractory Primary Central Nervous System Lymphoma: A Prospective Single-Arm Phase II Study

The prognosis of relapsed/refractory (R/R) primary central nervous system lymphoma (PCNSL) is dismal, and there are limited treatment options for these patients. This was a prospective single-arm phase II study of combined pemetrexed and lenalidomide for salvage treatment of R/R PCNSL. Patients with R/R PCNSL (n = 38) who had undergone two or more different therapeutic regimens and experienced disease progression or recurrence were enrolled. The primary endpoint was overall response rate (ORR). Secondary endpoints were progression-free survival (PFS) and overall survival (OS). Patients were followed up for a median of 18 (range, 1–36) months. ORR was 68.4%, with median PFS and OS of 6 and 18 months, respectively. Adverse events (AEs) included myelosuppression, fatigue, nausea, fever, infection, cardiac disease, and thrombogenesis. Commonly observed grade ≥ 3 AEs included neutropenia (5.3%), leukopenia (2.6%), thrombocytopenia (7.9%), and infection (2.6%). Elevated lactate dehydrogenase (LDH) levels (χ2 = 13.25; P = 0.0003) and bulky disease (P = 0.032; χ2 = 4.580) were associated with short PFS. Elevated serum LDH level (P = 0.011; χ2 = 6.560), abnormal lymphoma cells in the cerebrospinal fluid (CSF) [P = 0.011; χ2 = 6.445], and multiple lesions (P = 0.036; χ2 = 4.404) were significantly associated with poorer OS. Abnormal lymphoma cells in the CSF were an independent predictor of poor prognosis on multivariate analysis (P = 0.034; hazard ratio (HR) = 2.836; 95% confidence interval, 1.082–7.434). Our results indicate that pemetrexed plus lenalidomide is effective for heavily treated R/R PCNSL, with moderate toxicity. Trial registration: #ChiCTR1900028070.

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.

Central Nervous System Lymphoma: Novel Therapies

OPINION STATEMENT

Primary central nervous system lymphomas (PCNSLs) are very rare neoplasms and continue to be challenging to treat. While high-dose methotrexate (HD-MTX)-based regimens are the currently accepted standard first-line therapy for newly diagnosed patients, the optimal induction therapies are still unknown. The role of consolidation therapies continues to evolve with a variety of chemotherapy regimens, including high-dose chemotherapy with stem cell rescue and reduced or deferred whole brain radiotherapy being used. Importantly, several recent advances have been made in the treatment of PCNSL. The incorporation of targeted therapy and immune therapy remain promising strategies. Several agents, successfully used in treatment of systemic lymphomas, have shown activity in PCNSL, frequently leading to durable responses in the relapsed/refractory patients. Many ongoing studies will likely lead to a better understanding of the roles of these treatments, especially as the first line and potentially also as maintenance. In addition, the use of molecular profiling to predict disease response to targeted agents and understand relapse patterns will become increasingly important. Clinical trials in PCNSL are critical yet frequently challenging to conduct given the rarity of the condition and lack of suitable subjects. Therefore, multi-institutional and international collaboration is of utmost importance to accelerate progress in understanding the biology and design better treatments for this disease. It is critical to consider patients of all demographics in the design and study of future treatment algorithms to have the largest impact on patient care and outcomes.

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.

A single-center retrospective analysis of outcome measures and consolidation strategies for relapsed and refractory primary CNS lymphoma

BACKGROUND

Relapsed or refractory primary CNS lymphoma (rrPCNSL) is a rare and challenging malignancy for which better evidence is needed to guide management.

METHODS

We present a retrospective cohort of 66 consecutive patients with rrPCNSL treated at the University of Washington between 2000 and 2020. Immunosuppressed and secondary CNS lymphoma patients were excluded.

RESULTS

During a median follow-up of 40.5 months from initial diagnosis, median OS for relapsed disease was 14.1 (0.2-88.5) months and median PFS was 11.0 (0.2-73.9) months. At diagnosis (r² = 0.85, p < 0.001), first relapse (r² = 0.69, p < 0.001), multiple relapses (r² = 0.97, p < 0.001) PFS was highly correlated with OS. In contrast, there was no correlation between the duration of subsequent progression-free intervals. No difference in PFS or OS was seen between CSF or intraocular relapse and parenchymal relapse. Patients reinduced with high-dose methotrexate-based (HD-MTX) regimens had an overall response rate (ORR) of 86.7%. Consolidation with autologous stem cell transplant (ASCT) was associated with longer PFS compared to either no consolidation (p = 0.01) and trended to longer PFS when compared to other consolidation strategies (p = 0.06). OS was similarly improved in patients consolidated with ASCT compared with no consolidation (p = 0.04), but not compared with other consolidation (p = 0.22). Although patients receiving ASCT were younger, KPS, sex, and number of recurrences were similar between consolidation groups. A multivariate analysis confirmed an independent effect of consolidation group on PFS (p = 0.01), but not OS.

CONCLUSIONS

PFS may be a useful surrogate endpoint which predicts OS in PCNSL. Consolidation with ASCT was associated with improved PFS in rrPCNSL.

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.

Intrathecal pemetrexed combined with involved-field radiotherapy as a first-line intra-CSF therapy for leptomeningeal metastases from solid tumors: a phase I/II study

Purpose:

A phase I/II study of intrathecal pemetrexed (IP) combined with involved-field radiotherapy (IFRT) was performed to determine feasibility, safety, and antitumor activity for leptomeningeal metastases (LM) from solid tumors.

Methods:

Participants first received induction IP administration, followed by concomitant radiotherapy within 3 days. The concomitant regimen consisted of IP (pemetrexed 10 mg, dexamethasone 5 mg, once per week, 4 times in 4 weeks) and IFRT (40 Gy in 20 fractions). Six participants were recruited to assess feasibility in phase I, and then 28 patients were recruited further. All patients were assessed to investigate safety, efficacy, and outcomes.

Results:

Between April 2018 and December 2018, 34 patients (male: 15; female: 19; median age: 56 years) were enrolled, including non-small-cell lung cancer (21), small-cell lung cancer (5), breast cancer (4), and others (4). Thirty-two patients received concurrent therapy and 25 (74%) patients completed the treatment. Major adverse events (AEs) consisted of myelosuppression, the elevation of hepatic aminotransferases, and radiculitis. Total AEs rate was 53% (18/34), including 6 (18%) patients with grade 3 and 1 (3%) with grade 4 AEs. The response rate was 68% (23/34). The median overall survival was 5.5 (0.3–16.6) months. Median neurological progression-free survival (NPFS) was 3.5 (0.3–15.2) months. Six-month NPFS rate was 47%. One-year survival rate was 21.6%.

Conclusion:

IP at a 10 mg dose on a schedule of 1–2 times per week presented good efficacy and safety in CSF. The concomitant regimen is an efficacious therapeutic option for LM patients with solid tumors.

Trial Registration:

This study (IPLM) was registered at https://register.clinicaltrials.gov [ClinicalTrials.gov identifier: NCT03507244].

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.

Cerebrospinal fluid-based metabolomics to characterize different types of brain tumors

BACKGROUND

Brain tumors cause significant morbidity and mortality due to rapid progression and high recurrence risks. Reliable biomarkers to improve diagnosis thereof are desirable.

OBJECTIVE

This work aimed to identify panels of biomarkers for diagnostic purposes using cerebrospinal fluid (CSF)-based metabolomics.

METHODS

A cohort of 163 histologically-proven patients with brain disorders was involved. Comprehensive CSF-based metabolomics was achieved by liquid chromatography-quadrupole time-of-flight spectrometric (LC-Q/TOF-MS) and multivariate statistical analyses. The diagnostic performance of the metabolic markers was evaluated using receiver operating characteristic curves.

RESULTS

A total of 508 ion features were detected by the LC-Q/TOF-MS analysis, of which 27 metabolites were selected as diagnostic markers to discriminate different brain tumor types. The area under the curve (AUC) was 0.91 for lung adenocarcinoma patients with brain metastases (MBT) vs. lung adenocarcinoma patients without brain metastases (NMBT), 0.83 for primary central nervous system lymphoma (PCNSL) vs. secondary central nervous system involvement of systemic lymphoma (SCNSL), 0.77 for PCNSL vs. MBT, 0.87 for SCNSL vs. MBT, 0.86 for MBT vs. nontumorous brain diseases (NT), and 0.80 for PCNSL vs. NT. Perturbed metabolic pathways between the comparisons related mainly to amino acids and citrate metabolism.

CONCLUSIONS

CSF-based metabolomics to a large extent reliably identifies significant metabolic differences between different brain tumors and shows great potential for diagnosis of brain tumors.

A Pilot Phase 1 Study of Intrathecal Pemetrexed for Refractory Leptomeningeal Metastases From Non-small-cell Lung Cancer

Objectives: We aim to determine the feasibility, safety, maximally tolerated dose (MTD), recommended dose and potential anti-tumor activity of intrathecal pemetrexed (IP).

Materials and Methods: Lung adenocarcinoma patients with recurrent or progressive leptomeningeal metastases (LM) after intrathecal chemotherapy were recruited. IP dose was escalated from 10 mg. A minimum of three patients and a maximum of six were enrolled in each cohort. Schedule protocol was IP twice per week for 2 weeks in induction therapy, followed by once per week for 4 weeks in consolidation therapy. Serial samples of plasma and cerebrospinal fluid (CSF) were obtained for pharmacokinetic studies.

Results: Thirteen patients were enrolled between March 2017 and July 2018. EGFR driver oncogene was identified in most of the patients. Severe adverse events (AEs) were encountered in 31% (4/13) of the cases, including myelosuppression, radiculitis, and elevation of hepatic aminotransferases (EHA). Study protocol was revised due to lethal myelosuppression. Following protocol revision, vitamin B12 and folic acid supplementation was given at the beginning of treatment, and myelosuppression was well-controlled. Dose-limiting toxicities (DLT) were myelosuppression, radiculitis, and EHA. Two patients (2/2) developed dose-limiting myelosuppression at 15 mg level. One patient (1/6) experienced dose-limiting radiculitis and EHA at 10 mg level. MTD was 10 mg. Response rate was 31% (4/13) and disease control rate was 54% (7/13). The drug concentration showed a decreasing trend in serial CSF samples following each IP. After IP, the peak plasma concentration was reached at 4 h in two cases, 6 h in two cases, 9 h in one case, and 12 h in one case, respectively.

Conclusion: Pemetrexed was appropriate for intrathecal administration. IP at 10 mg dose in combination with vitamin supplementation on the schedule of 1–2 times per week showed controllable toxicity and good efficacy. This regimen paves the way for subsequent clinical trial.

Clinical Trial Registration:www.ClinicalTrials.gov, identifier NCT03101579.

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.

Pemetrexed exerts anticancer effects by inducing G0/G1-phase cell cycle arrest and activating the NOXA/Mcl-1 axis in human esophageal squamous cell carcinoma cells

Esophageal squamous cell carcinoma (ESCC) is a dominant histological subtype of esophageal cancer with notably high incidence and mortality rates. Pemetrexed is a clinical antifolate therapeutic agent with anticancer properties. The present study aimed to understand whether pemetrexed is able to exert anticancer effects on ESCC cells, and to determine the underlying molecular mechanism. ESCC cells were treated with pemetrexed and cell survival was assessed with MTT assays. The cell cycle and apoptosis were evaluated using flow cytometry analysis, and proteins were detected using western blotting. It was demonstrated that pemetrexed inhibited cell survival and induced G₀/G₁ cell cycle arrest and apoptosis in human ESCC cells. Furthermore, the results demonstrated that the phorbol-12-myristate-13-acetate-induced protein 1/induced myeloid leukemia cell differentiation protein Mcl-1 axis is involved in intrinsic apoptosis induced by pemetrexed. The protein expression of endoplasmic reticulum stress markers inositol-requiring enzyme 1α, binding immunoglobulin protein and CCAAT-enhancer-binding protein homologous protein were upregulated following treatment with pemetrexed. These results suggest that pemetrexed may induce an endoplasmic reticulum stress response while activating intrinsic apoptosis. The present study provided important mechanistic insights into potential cancer treatments involving pemetrexed and enhanced the understanding of human ESCC.

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.

Improving outcomes in primary CNS lymphoma

Primary central nervous system lymphoma (PCNSL) is an aggressive disease with previously poor prognosis. The advent of high-dose methotrexate-based induction regimens as well as use of consolidation therapy has greatly improved this prognosis in recent decades, but durable remission still eludes half of patients. In this review, we summarize the progress made in the treatment of PCNSL as well as the challenges that remain, with a focus on defining optimal induction and consolidation regimens, including the promise of developing biotherapies. Future studies will help delineate the best combination of existing and novel treatment strategies, with the goal of expanding the cohort of patients achieving a cure.

The Diagnosis and Treatment of Primary CNS Lymphoma

BACKGROUND

Primary central nervous system lymphoma is a diffuse large B-celllymphoma with exclusive manifestation in the central nervous system (CNS), leptomeninges, and eyes. Its incidence is 0.5 per 100 000 persons per year.Currently, no evidence-based standard of care exists.

METHODS

This review is based on pertinent publications (2000-2017) retrieved by aselective search in PubMed.

RESULTS

The clinical and neuroradiological presentation of primary CNS lymphoma isoften nonspecific, and histopathological confirmation is obligatory. The disease, if left un- treated, leads to death within weeks or months. If the patient's general condition permits, treatment should consist of a high-dose chemotherapy based on methotrexate (HD- MTX) combined with rituximab and other cytostatic drugs that penetrate the blood-brain barrier. Long-term survival can be achieved in patients under age 70 by adding non- myeloablative consolidation chemotherapy or high-dose chemotherapy with autologous stem cell transplantation (HD-AST) to the induction therapy. Clinical trials comparing the efficacy and toxicity of these two treatment strategies are currently underway. Con- solidation whole-brain radiotherapy is associated with the risk of severe neurotoxicity and should be reserved for patients who do not qualify for systemic treatment. Some 30% of patients are refractory to primary treatment, and at least 50% relapse. In patients who are still in good general condition, relapse can be managed with HD-AST. Re- exposure to conventional HD-MTX-based polychemotherapy is another option, if the initial response was durable. The 5-year survival rate of all treated patients is 31%,according to registry data.

CONCLUSION

Current recommendations for the treatment of primary CNS lymphomaare based on only a small number of prospective clinical trials. Patients with this disease should be treated by interdisciplinary teams in experienced centers, andpreferably as part of a controlled trial.

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

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

Primary CNS Lymphoma

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

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Primary CNS lymphoma

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

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

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

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.

A Rare Case of Primary Gastric HIV-Associated Peripheral T-Cell Lymphoma: Relapsed Disease Treated With Pemetrexed

We present a case of a patient with HIV/AIDS who presented with abdominal pain and melena and was found to have gastric peripheral T-cell lymphoma (PTCL). He was treated with 6 cycles of EPOCH with a complete response. Within 3 months, he had central nervous system (CNS) and soft-tissue relapse. He was subsequently treated with 3 cycles of intravenous pemetrexed and experienced a second complete response. To our knowledge, there are fewer than 100 reports of HIV-associated PTCL worldwide as of 2010, and among these cases involvement of the stomach as the primary site of extranodal disease is exceptionally rare. The disease carries a poor prognosis and current standard therapies highlight the importance of HIV/AIDS disease control and the need for more studies on therapies and the role of transplantation in refractory or relapsed HIV-associated PTCL.