Treatment Of Primary Central Nervous System Lymphoma Research Articles

Orelabrutinib, rituximab, temozolomide and high-dose methotrexate (RMOT) in newly diagnosed primary central nervous system lymphoma (PCNSL): A retrospective analysis on efficacy and safety.

e19041 Background: PCNSL is a rare, aggressive malignant tumor and has a poor prognosis. HD-MTX-based regimen is the first-line treatment of PCNSL. Orelabrutinib is a novel, potent, highly selective BTK inhibitor with a high CSF concentration. Recent evidence has shown the efficacy and safety of orelabrutinib in PCNSL. Therefore, we conducted a retrospective study of clinical outcomes in newly diagnosed PCNSL patients (pts) treated with RMOT regimen in routine clinical care. Methods: This retrospective cohort included the pts (aged 18-80 years) with newly diagnosed PCNSL who received 6 cycles of RMOT regimen (rituximab 375 mg/m2 iv day 1; MTX 3.5 g/m2 iv day 1; temozolomide 150 mg/m2 po day 1 to day 5; orelabrutinib 150 mg qd po; 4 weeks per cycle) as the first-line induction therapy between Nov. 2021 and Aug. 2023. All the pts were proposed to receive orelabrutinib monotherapy as maintenance after RMOT therapy. We recommend to receive autologous stem cell transplantation (ASCT) or whole brain radiation therapy (WBRT) as consolidation after RMOT therapy. Efficacy was assessed by MRI/PET per the International PCNSL Collaborative Group (IPCG) criteria. The primary endpoint was overall response rate (ORR); secondary endpoints were CR rate, progression-free survival (PFS), overall survival (OS), and safety. Results: Ten pts (6 males) with PCNSL were included, with a median age of 61 years (range, 45-77). All pts had a histologically confirmed diffuse large B-cell lymphoma. 4 pts (40%) underwent WBRT after induction therapy. As of the cut-off date (December 31, 2023), the median follow-up time was 9.7 (range, 4.8-25.7) month. All pts were evaluated for the treatment response. An interim evaluation after 4 cycles was available for 10 pts, showing complete remission (CR) rate of 80% (8/10), partial response (PR) rate of 20% (2/10), giving an ORR of 100.0% (10/10, Table). At data cutoff, the best ORR was 100.0% (10/10), with all pts achieved CR. Of 10 responders, 9 had an ongoing response, and 1 died of covid-19 infection. Median PFS/OS was not reached (NR) (95% CI NR-NR). The most common AEs were anemia, other include white blood cell or platelet count decreased. Reported AEs were generally manageable and resolved soon after supportive treatment. Only 1 (10%) pts experienced ≥grade 3 AEs—acute kidney injury. No treatment-related death occurred. Conclusions: This retrospective data suggested that RMOT had an encouraging anti-tumor activity in newly diagnosed PCNSL pts, with a toleratable safety profile. This orelabrutinib-containing regimens may provide a potential treatment strategy for pts with PCNSL. [Table: see text]

Survival outcomes and treatment experience of 124patients with primary central nervous system lymphoma.

Primary central nervous system lymphoma (PCNSL) is arare malignancy of the central nervous system with high invasiveness. There is little consensus on the treatment of PCNSL. This study retrospectively studied data from PCNSL patients in asingle center to summarize treatment experience and explore prognostic factors. Survival curves were drawn using the Kaplan-Meier method and prognostic factors were analyzed using Cox's hazards model. In multivariate analysis, cerebrospinal fluid lactic acid dehydrogenase (CSF LDH; p = 0.005 and p = 0.002), neutrophil to lymphocyte ratio (NLR; p = 0.014 and p = 0.038), and completion of four cycles of induction therapy (p < 0.001and p < 0.001) were significant and independent predictors of overall survival (OS) and progression-free survival (PFS), respectively. On the basis of this study, we propose that PCNSL patients should receive early induction therapy with sufficient cycles. Subsequent consolidation therapy can prevent relapses and improve survival. In patients with PCNSL, the independent prognostic factors for OS and PFS were CSF LDH level, NLR, and full cycles of induction therapy.

Zanubrutinib plus Cytarabine in Patients with Refractory/Relapsed Primary Central Nervous System Lymphoma

Introduction: Primary central nervous system lymphoma (PCNSL) is a rare subtype of aggressive extranodal non-Hodgkin lymphoma. Currently, there is no standard of care for the treatment of refractory or relapsed PCNSL (r/r PCNSL). We conducted a prospective single-arm phase II study to evaluate zanubrutinib plus cytarabine for r/r PCNSL. Methods: Using Simon’s two-stage design, we analyzed 34 patients who received high-dose cytarabine (3.0 g/m2 once daily) for 2 days and zanubrutinib (160 mg twice daily) for 21 days each cycle for up to 6 cycles. The study was registered at www.chictr.org.cn as #ChiCTR2000039229. Results: The median follow-up was 19 months. The overall response rate was 64.7% (95% confidence interval [CI], 47.9–78.5%) with a complete remission or unconfirmed complete remission rate of 47.1% (16/34) and a partial remission rate of 17.6% (6/34). The median progression-free survival was 4.5 months (95% CI, 1.5–9.4), and the median OS was 18 months (95% CI, 9.5 to not estimable). The median duration of the response was 9 months (95% CI, 3.2 to not estimable). The most common treatment-emergent adverse events were thrombocytopenia (55.9%). No treatment-related death occurred. Conclusion: Zanubrutinib and cytarabine showed efficacy in r/r PCNSL with an acceptable safety profile.

Primary Central Nervous System Lymphoma, Treatment Outcomes - 10 Year Experience. Single Center Study.

Primary central nervous system lymphoma(PCNSL) is an aggressive, rare form of Non-Hodgkin lymphoma, characterized by the absence of systemic disease. There are limited data and no strictly defined guidelines for management of PCNSL. The aim of this study was to report a 10 year experience of PCNSL treatment, to evaluate treatment outcomes and asses Progression Free and Overall Survival of these patients. Study was conducted on the Haematology Clinic, Clinical center University of Sarajevo, BH, in the period from January 2012.-December 2022. Total sample of 24 patients were enrolled. All have undergone diagnostic surgery. Patients were treated with regimens based on High dose Methotrexate, with/without whole brain radiotherapy as consolidation. Treatment response was captured by imaging techniques. Patients who have relapsed were evaluated with imaging techniques and treated according to Methotrexate-based treatment protocols. We have captured equal gender distribution. The median age of patients was 59.5 years (range 20-79). Pathohistological analysis confirmed DLBCL diagnosis in 22 patients, T cell lymphoma and anaplastic large cell lymphoma, each in 1 patient. Chemotherapy, chemotherapy combined with WBRT and radiotherapy were given to 5, 18 and 1 patients, respectively. The overall complete response rate (CR) was 87,15%. Those receiving combined modality-treatment had higher CR than those receiving chemotherapy (94,4% versus 60%). Out of 24 patients, 11 of them relapsed. The median time to relapse was 29 months (from 1 to 105). After second line of the treatment, CR was 54,5%, while 45,45% of patients died during the treatment. 4 patients relapsed for the second time with median time to relapse of 9 months (from 2 to 77). 2 year OS rate was 67%, and the median OS rate was 45,9 months. 2 year PFS rate was 31%. The OS and PFS rates indicate the usage of new drugs and consolidation with autologous stem cell transplantation in patients with PCNSL in order to achieve better treatment outcomes.

10203-ML-6 TIRABRUTINIB FOR PRIMARY CNS LYMPHOMA: A SINGLE INSTITUTE RETROSPECTIVE ANALYSIS

Abstract In 2020, Tirabrutinib (TIR) was approved in Japan as a novel treatment for primary CNS lymphoma (PCNSL). However, the position of TIR in relation to the existing therapy, methotrexate (MTX)-based therapy, is still unclear. We are currently using TIR for patients who have insensitivity to MTX, have short-term recurrence after MTX, or have difficulty receiving MTX, with the principle of readministering MTX-based therapy to patients with recurrent disease. The subjects were ten patients treated with TIR at our institute, 6 with multiple relapses, 3 with inability to MTX, and 1 with difficulty in MTX treatment, and the mean number of relapses was 3.8 when Tirabrutinib was used. The mean number of treatments was 104 days, and 7 patients discontinued treatment due to tumor progression, while 3 patients discontinued due to severe skin problems. The median progression-free survival was 99 days, and only one patient was controlled for more than one year. 4 patients received the best supportive care for recurrence after TIR, and one patient received radiotherapy. The four patients in the MTX-based retreatment group had two progressions and two no progressions at the time of the abstract, with a progression-free survival of 133 days, and two patients had CTCAE grade 4 hematologic toxicities that had not occurred with previous therapy. One patient treated surgically died of postoperative pneumocystis pneumonia. Tirabrutinib showed a high early response rate, but the duration of tumor control tended to be shorter than with MTX-based retreatment. This may be due to its use in our institution after multiple relapses and its aggressive administration in MTX-naive patients. It is also important to note that chemotherapy after TIR use is associated with increased hematologic toxicity.

Impact of Folinic Acid Dosing on Efficacy and Toxicity of High-Dose Methotrexate in Central Nervous System Lymphoma

Treatment of primary central nervous system lymphoma (PCNSL) is centered around a backbone of high-dose methotrexate (HDMTX) with folinic acid (FA) rescue. Higher FA doses were associated with treatment failure in several retrospective studies in acute lymphatic leukemia (ALL), leading to the adoption of lower FA doses in ALL treatment protocols. In PCNSL, FA doses have varied widely, guidelines and consensus statements generally do not address FA dosing, and the effect of FA dosing on treatment outcomes has not been assessed. We retrospectively analyzed the medical records of patients treated at our institute for PCNSL between the years 2014 and 2022 to address this question. Patient characteristics are listed in table 1. Complete dosing data was available for 36 patients. The median number of HDMTX doses administered was 6.5 (range, 2-9;), with an average dose of 3.9 g/m 2 (SD +/- 0.74; range, 2.7-5.0). Per the local protocol, IV FA rescue began 24 hours after each MTX infusion at a fixed dose of 50 mg four times daily and continued until MTX clearance. The average cumulative dose of FA administered per treatment was 322 mg/m 2 (SD +/- 141; range, 140-700). 33 patients (92%) achieved either a partial or complete response on MRI following induction treatment. Three (8%) had progressive disease. 26 patients (72%) proceeded with consolidation treatment. Of these, 16 (44%) underwent autologous hematopoietic stem cell transplant. At a median follow up of 1.6 years (range, 0.3-8.1), 12 patients (33%) suffered progressive disease, disease relapse, or death. The 2-year PFS probability for the entire cohort was estimated at 64.5% (95% confidence interval [CI], 49.4-84.1%), and the 2-year OS as 70.7% (95% CI 56.0-89.2%). In univariate Cox regression analysis, average FA dose during MTX treatment was a significant predictor of both PFS and OS, with hazard ratios (HR) of 2.22 (95% CI 1.39-3.55; p &amp;lt; 0.001) and 2.07 (95% CI 1.31-3.29; p = 0.002), respectively, for each 100 mg/m 2 increase. The FA dose during the first treatment cycle, before assessment of response, was also significantly associated with worse PFS (HR 1.56; 95% CI 1.24-1.96; p &amp;lt; 0.001) and OS (HR 1.41; 95% CI 1.14-1.74; p = 0.001). A trend towards worse PFS and OS was seen with male gender, elevated serum LDH, and deep structure involvement. A Cox multivariate regression analysis using the variables age, gender, serum LDH, deep structure involvement, and the average MTX and FA doses, identified FA dose as an independent prognostic factor for PFS, with an estimated hazard ratio (HR) of 2.23 for each 100 mg/m 2 increase (95% CI, 1.25-3.97; p = 0.006). A smaller effect was seen when the FA dose during only the first treatment cycle was examined (HR 1.55; 95% CI 1.16-2.08; p = 0.003). Involvement of deep structures was also significantly associated with worse PFS, with an estimated HR of 8.59 (95% CI, 1.28-57.5; p = 0.027), and there was a borderline significant trend for worse PFS with male gender and elevated LDH. None of the examined variables were identified as statistically significant predictors of OS in the multivariate analysis. Logistic regression with 2-year PFS as the dependent variable was used to define a cutoff value of 350 mg/m 2 for FA dose. The group of patients who received FA doses above and below this threshold showed significantly different PFS curves (figure 1). The 2-year PFS probability was estimated at 56.6% (95% CI, 35.4-90.5%) for patients who received doses of FA above this threshold, and 70.5% (95% CI, 51.7%-96.2%) for patients who received doses below it. We identified no effect of FA dosing on hematologic, renal, hepatic, or gastrointestinal toxicity at the dose ranges examined. In summary, we found that high FA doses were associated with inferior PFS in PCNSL. Such high doses may be avoided through use of lower individual doses of FA, such as 15 mg/m 2 or 25 mg fixed doses as have been used in some protocols, rather than the 50 mg or higher doses used in our and other's practice. Our conclusions are moderated by the study's limitations, which include a small sample size limited to a single center and a retrospective design. However, they suggest that optimizing FA dosing in treatment of PCNSL might improve treatment efficacy without excess toxicity. Future larger and prospective studies will be required to better define the range of MTX and FA doses at which the balance between prevention of treatment toxicity and preservation of treatment efficacy is preserved.

Combination of Selinexor with BTK Inhibitor for Central Nervous System Diffuse Large B-Cell Lymphoma, Possible Mechanisms and Therapeutic Potential Exploration

Background: Primary central nervous system lymphoma (PCNSL) is a rare aggressive extra-nodal non-Hodgkin lymphoma (NHL) of which over 90% are diffuse large B-cell lymphoma (DLBCL). High-dose methotrexate (HD-MTX)-based regimens are the dominant therapy for newly diagnosed PCNSL, but the patients' complete remission rate (CRR) is merely about 50%. Bruton tyrosine kinase (BTK), a critical kinase in the B cell receptor (BCR) signaling pathway, contributes to the degradation of FOXO3a and promotes abnormal B cell proliferation. Recent studies revealed that BTK inhibitors (BTKi) play a role in various B cell lymphomas, including DLBCL, and have also shown promising efficacy in PCNSL. However, the clinical management of PCNSL is still challenging for its limited treatment options and poor prognosis, especially when patients developed acquired resistance to BTKi. Selinexor (KPT-330) is a first-ever oral small molecule Exportin-1 (nuclear output protein XPO1) inhibitor with a molecular weight of 443.31 Da, which can efficiently cross the blood-brain barrier. Currently Selinexor was found to promote the aggregation of FOXO3a and could synergistically inhibit PI3K/AKT and NF-κB pathways with BTKi to overcome acquired BTKi resistance. To investigate the therapeutic potential of Selinexor and BTKi in PCNSL, we examined the combination both in DLBCL cells and A20 transplantation mice, and further explored the clinical efficacy in PCNSL patients. Methods and Results: ABC-DLBCL cell lines (OCI-LY3 and OCI-LY10) were treated with Selinexor for 48 hours. Western blot analysis showed that Selinexor inhibited NF-κB, P-STAT3, and NFATc1 signaling pathways in DLBCL in vitro. Combining Selinexor(1μM) with ICP-022(2μM), a BTKi, resulted in more notable inhibition of the above tumor signaling pathways. A20 murine B-cell lymphoma transplantation models were divided into a control group, Selinexor monotherapy group, ICP-022 monotherapy group, and combination group. Tumor volume was measured after 30 days (Figures 1A), and the number of CD4+ T cells and CD8+ T cells and the corresponding cellular expression of PD-1 and TIM-3 in the spleen and tumor tissues of mice were detected. The results showed that the tumor volume in the combination group was minimized, and the number of CD4+ T cells and CD8+ T cells in spleens and tumors in this group was significantly increased, while PD-1 and TIM-3 expression was downregulated (Figures 1B-C). Based on these results, a prospective, open-label, single-arm, multicenter study was conducted with MSZ regimen (MTX, BTKi, Selinexor) for the treatment of PCNSL (Trial Registration Number: ChiCTR2200062154). Newly diagnosed primary and secondary central DLBCL patients (18-80 years old) received a 6-cycle MSZ regimen (HDMTX 3.5 g/m 2 3-h infusion d1, Zanubrutinib 160 mg Bid po, Selinexor 40 mg Biw po, 3 weeks per cycle) and evaluated by MRI/PET. 5 patients (2 GCB-DLBCL, 3 ABC-DLBCL) were enrolled, with a median age of 65 years (range: 54-73 years), 100% achieved metabolic remission (Figure 2A) and maintained long-term efficacy. 4 patients achieved early deep remissions of over 75% reduction with 1 cycle of treatment, and 1 patient had a complete remission after 2 cycles of treatment (Figures 2B). 3 patients chose radiation therapy as consolidation after the end of induction chemotherapy. 2 others were on maintenance therapy with Selinexor combined with Zanubrutinib, one of them has completed the two-year maintenance treatment and maintained sustained remission till now. Only 1 patient experienced several grade 3 adverse events (AEs) including anemia, decreased white blood cell and platelet counts, and elevated alanine aminotransferase.1 patient developed mild renal insufficiency, which recovered 6 months after the end of treatment. Patients were generally well-tolerated and there were no treatment-related deaths. Conclusion: This is the first report describing that Selinexor combined with BTKi can synergistically inhibit the DLBCL tumor signaling pathway and repairing the immune microenvironment. Correspondingly, in treatment of central DLBCL patients, the novel therapeutic strategy of MSZ regimen has achieved impressive results, with a CRR of 100%. Most patients attained early and rapid deep remissions with durable efficacy. This study provides theoretical support and preliminary clinical data for the combined application of Selinexor and BTK inhibitors.

Phase 1 Trial of Orelabrutinib in Combination with Rituximab, Methotrexate, and Dexamethasone in Patients with Newly Diagnosed Primary CNS Lymphoma Implementing Bayesian Design for Dose-Seeking

Background: Primary central nervous system lymphoma (PCNSL) is an aggressive extranodal subtype of non-Hodgkin's lymphoma (NHL). High-dose methotrexate (HD-MTX)-based regimens are the first-line treatment for PCNSL, but remain suboptimal due to response instability and short effective remission duration. Orelabrutinib is a novel, potent, highly selective BTK inhibitor with a high CSF concentration. This study aims to investigate optimal combination dose of Orelabrutinib in combination with Rituximab, Methotrexate, and Dexamethasone (ORMD) as well as safety and efficacy of the regimen. Methods: This was a phase 1, investigator-initiated, dose-escalation study of ORMD, being conducted at Huashan Hospital, Fudan University (NCT05036577). Eligible patients must have histopathologically confirmed PCNSL-DLBCL by biopsy of brain lesions and be aged 18-75 years with adequate organ functions. Patients were treated for 6-8 cycles of induction therapy with 21 days per cycle, receiving rituximab (375mg/m 2 on day 1), dexamethasone (10-15mg on d1-d4), MTX (d2, 3.5g/m 2 or 5g/m 2), and orelabrutinib (once daily, after MTX clearance, 150mg/d, or 200mg/d), followed by orelabrutinib maintenance up to one year among CR/CRu patients. The primary objective was to determine the maximum tolerated dose (MTD) of the combination of orelabrutinib and MTX with R and D and investigate the safety and tolerability of this regimen using Bayesian Optimal Interval (BOIN) waterfall design to determine rule of dose escalation and movement among dose combination matrix to identify MTD contour. DLT was defined by the occurrence of severe toxicities during the first cycle: any grade 4 hematologic toxicity, grade 3 febrile neutropenia and grade 3 thrombocytopenia with hemorrhage, or any grade 3 non-hematologic toxicity that failed to respond to supportive therapy and possibly related to orelabrutinib and/or MTX (assessed according to NCI CTCAE V5.0). The secondary objectives included ORR/CR（u） and PFS/OS. Results: From October 2021 to July 2023, the study completed enrollment of all 13 patients. The median age was 60 years, and other basic characteristics are shown in Figure 1. All the patients had completed at least one cycle of ORMD treatment and were evaluable for DLT. The median cycle of ORMD was seven (range: 2.5-8). No DLT occurred among first 3 patients in cohort 1 (Orelabrutinib: 150mg/MTX: 3.5g/m 2) and dose escalation was allowed to cohort 2 (Orelabrutinib: 200mg/MTX: 3.5g/m 2). In cohort 2, 5 patients were dosed in total, and Gr 3 lung infection was observed in patient #4 during cycle 1, was deemed as a DLT. Another four patients were enrolled in the same cohort according to BOIN design algorithm and no DLT was identified, allowing to escalate to cohort 3 (Orelabrutinib:200mg/MTX:5g/m 2). In cohort 3, 5 patients were dosed in total, and Gr 3 elevation of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) was observed in patient #9 during cycle 1, was deemed as a DLT. The causality of this AE was certain to methotrexate due to folate metabolic gene polymorphism in the assessment of the investigator. The toxicity probability from 3 dose combo cohort is 0.13, 0.13 and 0.21, all of which is below predefined threshold 0.3. So MTD is not reached and 200mg+5g/m 2 dose combo remains to be RP2D candidate. No Gr 4 AE had been observed. The most common adverse events were lymphopenia (Gr 3 in 8 case), neutropenia(Gr 3 in 2 case), Covid-19(Gr 3 in 2 case) and hyperglycemia (Gr 3 in 2 case). No atrial fibrillation or bleeding was observed by the cut-off date. ORR and CR/CRu in 12 patients possessed at least one efficacy evaluation were both 83.3%, the PFS and OS rate were 56.6% (95% CI, 29.6% ,100%) and 100%(95% CI, 100% ,100%) at 1 year. Among nine patients completed ≥6 cycles of induction therapy, ORR and CR/CRu were both 100%. PFS and OS rate were 75.0% (95% CI, 42.6% ,100%) and 100%(95% CI, 100% ,100%) at 1 year. All patients in remission achieved CR/CRu, the high rate of deep remission may be related to the addition of orelabrutinib. Conclusions: As a novel therapeutic combination of induction therapy, ORMD therapy has shown deep remission potential as well as a predictable and manageable safety profile in patients with newly diagnosed PCNSL. MTD contour not reached. The combination of this induction therapy with consolidation therapies such as ASCT deserves further investigation and may provide greater survival benefit for patients.

Comparison of the outcomes of patients with primary central nervous system lymphoma between the neurosurgery and hematology/oncology departments based on the relative dose intensity of methotrexate.

Primary central nervous system lymphoma (PCNSL) is an extranodal type of lymphoma, which is treated with methotrexate (MTX)-based induction therapy. Although PCNSL is a hematological malignancy, patients with PCNSL may be treated at neurosurgery or hematology/oncology departments; however, the outcomes of PCNSL treatment have not been compared between these two departments. The present study compared the outcomes of 26 patients with newly diagnosed PCNSL that were treated at the Department of Neurological Surgery or Department of Hematology/Oncology (Wakayama Medical University Hospital, Wakayama, Japan) between January 2011 and December 2021. The relative dose intensity (RDI) and relative treatment intensity of MTX were assessed as indicators of the intensity of chemotherapy. The median RDI of MTX was 67 and 93% in the neurosurgery and hematology/oncology groups, respectively (P<0.001). The proportion of patients that achieved a complete response after high-dose MTX-based therapy was significantly higher in the hematology/oncology group than in the neurosurgery group (P=0.038). The estimated 2-year overall survival was 72 and 100% in the neurosurgery and hematology/oncology groups, respectively (P=0.046). As with the difference in the outcomes observed between pediatrics and hematology departments for adolescents with acute lymphoblastic leukemia, the outcomes of patients with PCNSL may differ between neurosurgery and hematology/oncology departments.

Recent advances and challenges in primary central nervous system lymphoma: a narrative review.

Primary central nervous system lymphoma (PCNSL) is a rare and highly invasive non-Hodgkin lymphoma that is challenging to diagnose and treat. It is typically confined to the brain, spinal cord, and eyes. The diagnosis of PCNSL lacks specificity, and the misdiagnosis and missed diagnosis rates of PCNSL are high. Traditional treatments for PCNSL, such as surgery, whole-brain radiation therapy, high-dose methotrexate-based chemotherapy, and rituximab (RTX), have been associated with higher initial remission rates. However, the duration of any remission is short, the recurrence rate is high, and treatment-related neurotoxicity is strong, which are challenges for medical researchers. This review provides an overview of and perspectives on the diagnosis, treatment, and evaluation of patients with PCNSL. The PubMed database was searched to retrieve articles published from January 1, 1991, to June 2, 2022 using the following Medical Subject Headings (MeSH) terms: "Primary central nervous system lymphoma" and "clinical trial". The American Society of Clinical Oncology and the National Comprehensive Cancer Network guidelines were also reviewed to obtain additional information. The search was limited to articles published in English, German, and French. In total, 126 articles were deemed eligible for inclusion in this study. In terms of the diagnosis of PCNSL, a combination of flow cytometry and cytology has been shown to improve the diagnostic accuracy of PCNSL. Additionally, interleukin 10 and chemokine C-X-C motif ligand 13 are promising biomarkers. In terms of the treatment of PCNSL, programmed death-1 (PD-1) blockage and chimeric antigen receptor T cell (CAR-T) therapy treatments have shown prospective efficacy, but more clinical trials need to be conducted to gather further evidence. We also reviewed and summarized prospective clinical trials on PCNSL. PCNSL is a rare and highly aggressive lymphoma. The treatment of PCNSL has progressed significantly, and while the survival of patients has improved, relapse and low long-term survival remain huge challenges. Continuous in-depth research is being conducted on new drug therapies and combination therapies for PCNSL. A combination of targeted drugs (e.g., ibrutinib, lenalidomide, and PD-1 monoclonal antibody) and traditional therapy represents the main research direction for future PCNSL treatments. CAR-T has also shown great potential in the treatment of PCNSL. With the development of these new diagnostic and therapeutic methods and further research into the molecular biology of PCNSL, patients with PCNSL should achieve a better prognosis.

A single-center, retrospective analysis of relapse and progression patterns of primary central nervous system lymphoma: can whole brain radiotherapy be replaced?

To analyze recurrence and progression patterns of primary central nervous system lymphoma (PCNSL) in patients without whole brain radiotherapy (WBRT) and assess the value of WBRT in PCNSL treatment. This retrospective single-center study included 27 patients with PCNSL, who experienced recurrence/progression after achieving complete remission (CR), partial remission, or stable disease following initial treatments with chemotherapy but without WBRT. The patients were followed up regularly after the treatment for treatment efficacy assessment. By comparing the anatomical location of the lesions on magnetic resonance images (MRI) at the initial diagnosis and at recurrence/progression, we analyzed the patterns of relapse/progression in patients with different treatment responses and different initial status of the lesions. MRI data showed that in 16 (59.26%) of the 27 patients, recurrence/progression occurred in out-field area (outside the simulated clinical target volume [CTV]) but within the simulated WBRT target area in 16 (59.26%) patients, and within the CTV (in-field) in 11 (40.74%) patients. None of the patients had extracranial recurrence of the tumor. Of the 11 patients who achieved CR after the initial treatments, 9 (81.82%) had PCNSL recurrences in the out-field area but within WBRT target area; of the 13 patients with a single lesion at the initial treatment, 11 (84.62%) experienced PCNSL recurrence in the out-field area but within WBRT target area. Systemic therapy combined with WBRT still remains the standard treatment for PCNSL patients, especially those who achieve CR after treatment or have a single initial lesion. Future prospective studies with larger sample sizes are needed to further explore the role of low-dose WBRT in PCNSL treatment.

Prognostic Factors of the Primary Central Nervous System Lymphoma: Clinical Experience from a Tertiary Care Center in the Middle East.

Aim Primary central nervous system lymphoma (PCNSL) is a rare extra nodal non-Hodgkin's lymphoma. The optimal treatment for PCNSL is still unclear. In this study, we present our experience with management of PCNSL in a tertiary care center in Iran. Methods In this retrospective study, 58 patients with tissue diagnosis of PCNSL were studied. All patients were treated with chemotherapy including intravenous high-dose methotrexate, rituximab and temozolomide and radiotherapy by the same oncologist. Statistical analysis was performed using SPSS. Results The mean overall survival (OS) in this study was 37.4 ± 13.6 months and the mean progression free survival (PFS) was 35.1 ± 9.8 months. The mean time to progression was 15.2 ± 8.79 months among 8 patients who experienced progression in this series. Finding of a positive CSF cytology was not linked with disease progression, while HIV infection and multifocal involvement at initial presentation were strongly linked to a lower PFS. The single most important factor affecting the OS was the histopathologic type of the PCNSL; two of the three patients who died from their disease in this series had non-B cell PCNSL, whereas only one patient with DLBCL died because of brainstem involvement. Conclusion The results of this study show a lower rate of HIV-infection in patients with PCNSL as compared to the series from the western countries. Non-B cell histopathology and HIV-infection were found to be associated with the dismal prognosis.

A Systematic Review of High-Dose Methotrexate for Adults with Primary Central Nervous System Lymphoma

Primary central nervous system lymphoma (PCNSL) is a highly aggressive non-Hodgkin lymphoma that is confined within the CNS. Due to its ability to cross the blood-brain barrier, high-dose methotrexate (HDMTX) is the backbone for induction chemotherapy. This systematic review was conducted to observe outcomes among different HDMTX doses (low, <3 g/m2; intermediate, 3-4.9 g/m2; high, ≥5 g/m2) and regimens used in the treatment of PCNSL. A PubMed search resulted in 26 articles reporting clinical trials using HDMTX for PCNSL, from which 35 treatment cohorts were identified for analysis. The median dose of HDMTX used for induction was 3.5 g/m2 (interquartile range IQR, 3-3.5); the intermediate dose was most frequently used in the studies examined (24 cohorts, 69%). Five cohorts used HDMTX monotherapy, 19 cohorts used HDMTX + polychemotherapy, and 11 cohorts used HDMTX + rituximab ± polychemotherapy. Pooled overall response rate (ORR) estimates for low, intermediate, and high dose HDMTX cohorts were 71%, 76%, and 76%, respectively. Pooled 2-year progression-free survival (PFS) estimates for low, intermediate, and high HDMTX dose cohorts were 50%, 51%, and 55%, respectively. Regimens that included rituximab showed a tendency to have higher ORR and 2-year PFS than those that did not include rituximab. These findings indicate that current protocols utilizing 3-4 g/m2 of HDMTX in combination with rituximab provide therapeutic efficacy in PCNSL.

Clinical Outcomes and Treatment Patterns of Primary Central Nervous System Lymphoma: Multicenter Retrospective Analysis

Objectives: Primary central nervous system lymphoma (PCNSL) is a rare malignant disease with poor prognosis. Its low incidence leads to challenges in decision-making for treatment. As a matter of fact, there is still no consensus on the appropriate treatment modalities. In this context, the objective of this study is to investigate and comparatively assess the efficacies of several treatment modalities in the treatment of PCNSL. Methods: Thirty-four patients diagnosed with PCNSL at 5 different hematology centers between 2007 and 2021 were included in the study. Patients’ data from all five centers were collected retrospectively. Since ibrutinib is not approved for this indication in Turkey, consent for off-label use of ibrutinib is obtained from each patient. Ethics committee approval was obtained on June 9, 2021 with decision number 2021/18-05. Results: The median age of the patients was 59 (min.: 22, max.: 78) years. The male-to-female ratio was 1.26/1. Nineteen (55.9%) patients had Eastern Cooperative Oncology Group (ECOG) performance score of ?2. Fifteen (44.1%) patients had normal lactate dehydrogenase (LDH) levels and only 14.7% of the patients had B symptoms at the time of diagnosis. Magnetic resonance imaging (MRI) revealed a single mass lesion in 14 (41.2%) patients. As an induction therapy, methotrexate-based regimen was administered in 29 (85.3%) patients. Only 14 of the 34 patients received 4 or more cycles of high-dose methotrexate (MTX). About 32.4% of the patients received radiation therapy (RT) during follow-up as a part of induction therapy. Five patients received only RT due to poor performance status. Ibrutinib was administered in 5 patients for refractory disease. It was determined that four or more cycles of MTX treatment increased progression-free survival (PFS) (p=0.031) and overall survival (OS) (p=0.012). Moreover, RT improved PFS (p=0.023). Considering that the complete response achieved by induction therapy influences long-term survival, achievement of the best response to the treatment regimens administered in combination with new agents may prolong survival (PFS: p=0.01, OS: p=0.023). Conclusion: The findings of this study indicate that the initial response to treatment is crucial. Additionally, it was found that high-dose MTX treatment should be administered for 4 cycles or more in order to achieve the best results. Furthermore, it was determined that ibrutinib monotherapy was well-tolerated in our patients with relapsed/refractory disease, with excellent clinical benefits. In conclusion, a combination therapy consisting of high-dose MTX, ibrutinib, and rituximab appears to be a promising initial treatment approach in appropriate patients. Keywords: PCNSL, methotrexate, radiotherapy, ibrutinib

A case of primary central nervous system lymphoma with marked cauda equina enlargement

An 80-year-old woman presented with subacute right lower limb pain and bilateral lower limb weakness. MRI of the spine showed marked cauda equina enlargement with contrast enhancement. Cerebrospinal fluid (CSF) examination showed elevated cell count, decreased glucose, and elevated protein. Cytology of the CSF showed class V, which together with B-cell clonality by flow cytometry, led to the diagnosis of primary central nervous system lymphoma (PCNSL). The patient was treated with steroid, radiation, and chemotherapy. Despite the reduction in lesion size, her neurological symptoms revealed no improvement. PCNSL with cauda equina lesions are rare and often require highly invasive cauda equina biopsy for diagnosis. In recent years, some studies reported useful CSF biomarkers, but they may have some problems. Therefore, as in this case, the combination of cytology, flow cytometry and, CSF biomarkers could be a substitute method for invasive biopsies, and contribute to the early treatment of PCNSL.

Progress of radiological‑pathological workflows in the differential diagnosis between primary central nervous system lymphoma and high‑grade glioma (Review).

Primary central nervous system lymphoma (PCNSL) and high‑grade glioma (HGG) are distinct entities of the CNS with completely distinct treatments. The treatment of PCNSL is chemotherapy‑based, while surgery is the first choice for HGG. However, the clinical features of the two entities often overlap, and a clear pathological diagnosis is important for subsequent management, especially for the management of PCNSL. Stereotactic biopsy is recognized as one of the minimally invasive alternatives for evaluating the involvement of the CNS. However, in the case of limited tissue materials, the differential diagnosis between the two entities is still difficult. In addition, some patients are too ill to tolerate a needle biopsy. Therefore, combining imaging, histopathology and laboratory examinations is essential in order to make a clear diagnosis as soon as possible. The present study reviews the progress of comparative research on both imaging and laboratory tests based on the pathophysiological changes of the two entities, and proposes an integrative and optimized diagnostic process, with the purpose of building a better understanding for neurologists, hematologists, radiologists and pathologists.

ML-5 THE TRANSITION OF THE TREATMENT OF 60 PCNSL CASES AT OUR INSTITUTION AND CLINICAL CONSIDERATIONS

Abstract The efficacy of RMPV-A (rituximab, methotrexate, procarbazine, vincristine, and cytarabine) and whole brain irradiation for primary central nervous system lymphoma (PCNSL) have recently been reported. Our institution also introduced RMPV therapy in 2020 after an era of conventional HD-MTX to cytarabine and rituximab combination. In this report, we analyzed 60 PCNSL cases treated from 2013 to 2021.There were 32 female patients (53%) with a median age of 70 years (30-87). Five patients (8%) received radiotherapy alone as initial treatment, 30 (50%) received HD-MTX (including radiation), 17 (28%) received HD-MTX plus rituximab or cytarabine, and 9 (13%) received RMPV therapy. The response rate (CR, CRu, PR) in the HD-MTX group was 88%, and the complete response rate (CR, CRu) was 51%. In contrast, the RMPV arm had a response rate of 100% and a complete response rate of 6 patients (66.7%). 7 patients (14%) in the HD-MTX arm and 2 patients (22%) in the RMPV arm were unable to continue treatment due to adverse events. The treatment of PCNSL has undergone significant changes in recent years, with the availability of RMPV-A, thiotepa, and tirabrutinib, and it is now possible to construct treatment that avoids leukoencephalopathy caused by radiation therapy as much as possible, which had been a major problem of conventional therapy. However, because of the use of strong drugs, caution must be exercised when treating patients in poor general conditions, especially the elderly. However, the present analysis indicates that many elderly patients can be successfully treated with careful observation. In the future, it is essential to accumulate cases treated with RMPV therapy and tilabrutinib and conduct further data analysis to establish a new generation of treatment for PCNSL.

ML-9 TREATMENT OUTCOMES OF TIRABRUTINIB FOR RELAPSED AND REFRACTORY PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMA IN A SINGLE INSTITUTE

Abstract Recent clinical studies improved prognosis of primary central nervous system lymphoma (PCNSL) using multiple treatment reagents combined with radiation therapy. However, for recurrent and refractory cases after treatment with regimen consisting of multiple reagents, potent effective treatment has not been established yet. Tirabrutinib, Bruton's tyrosine kinase inhibitor was introduced for treatment of recurrent and refractory PCNSL in Japan. However, case series study investigating the clinical outcome of PCNSL cases treated with tirabrutinib have not been reported yet excepting for phase I/II study of tirabrutinib. We treated nine recurrent and two refractory cases. In all of these cases, except for one case exhibiting severe skin rash in spite of cessation of administration of tirabrutinib, we obtained favorable overall response rate (CR or Cru=5 and PR=5) together with favorable progression free survival (median; 339 days). Five cases exhibited skin rash (CTCAE grade 3; n=2 and grade 2; n=3). Grade 3 or 2 skin rash were found on day 9 or 75 of tirabrutinib treatment, respectively. In one case, MYD88 mutations in ctDNA derived from blood plasma were turned to be negative after one week administration of tirabrutinib. Although adverse effects such as skin rash was frequently found, tirabrutinib is effective for recurrent or refractory PCNSL cases. Our data suggested that treatment response of tirabrutinib could be evaluated via evaluation of copy number analysis of MYD88 mutations in ctDNA of blood plasma.

Bruton's tyrosine kinase inhibitors in the treatment of primary central nervous system lymphoma: A mini-review.

Primary central nervous system lymphoma (PCNSL) is a highly aggressive brain tumor with poor prognosis if no treatment. The activation of the NF-κB (nuclear factor kappa-B) is the oncogenic hallmark of PCNSL, and it was driven by B cell receptor (BCR) and Toll-like receptor (TLR) signaling pathways. The emergence of Bruton's tyrosine kinase inhibitors (BTKis) has brought the dawn of life to patients with PCNSL. This review summarizes the management of PCNSL with BTKis and potential molecular mechanisms of BTKi in the treatment of PCNSL. And the review will focus on the clinical applications of BTKi in the treatment of PCNSL including the efficacy and adverse events, the clinical trials currently being carried out, the underlying mechanisms of resistance to BTKi and possible solutions to drug resistance.

Efficacy Analysis of Bruton's Tyrosine Kinase Inhibitor Combined Regimen in the Treatment of Elderly Patients with Relapsed/Refractory Primary Central Nervous System Lymphoma

Background Primary central nervous system lymphoma (PCNSL) is a kind of aggressive non-Hodgkin lymphoma that originates in the brain, spinal cord, eyes or pia mater without evidence of systemic involvement, which accounts for about 3% of central nervous system tumors and has a poor prognosis. Most patients will eventually relapse and the 5-year survival rate is 29.6%. Zanubrutinib is a kind of new generation BTK inhibitor, which can penetrate the blood-brain barrier and be used in the treatment of PCNSL. The study aims to investigate the efficacy and safety of a zanubrutinib-based combination regimen in the treatment of elderly relapsed/refractory(R/R) PCNSL. Methods We retrospectively analyzed elderly patients with R/R PCNSL who received zanubrutinib-based combination regimen at the Affiliated Hospital of Nantong University over the past few years. We collected the information of patients diagnosed with PCNSL in the SEER project of the National Cancer Institute (NCI), and analyze the survival status. We used CCK8 and EdU to detect the effect of zanubrutinib on the viability and proliferation of activated B-cell subtype (ABC) diffuse large B-cell lymphoma (DLBCL) cell lines with genotypes similar to PCNSL. Results The 7 elderly R/R PCNSL patients treated with zanubrutinib-based regimen (zanubrutinib, rituximab and temozolomide) showed an overall response rate (ORR) of 85.7% (6/7), a complete response (CR) of 57.1% (4/7) and a partial response (PR) of 28.6% (2/7), and 14.3% (1/7) of patients experienced disease progression (PD). Patients' gender, KPS score, ECOG score, surgical treatment or not, positive cerebrospinal fluid protein (all P>0.05) were not significantly associated with the treatment effect. Pathological type and IESLG score were related to treatment effect (P<0.05). The median progression-free survival (PFS) and median overall survival (OS) of patients in this study were not reached. Through the analysis of clinical data of PCNSL patients in SEER database from 1975 to 2016, it is concluded that elderly patients (age>60 years old) and male PCNSL patients have a worse prognosis, the primary site of PCNSL, treatment methods and the choice of the disease have impact on the prognosis, and there is no significant difference between the disease and other causes in terms of the cause of death. In the survival analysis of elderly patients, gender, surgery and radiotherapy sequence had no significant effect on prognosis, and patients who received chemotherapy had better OS than those who received radiotherapy. The cell viability of ABC subtype DLBCL cell line OCI-Ly10 decreased in a concentration- and time-dependent manner with zanubrutinib and temozolomide (P<0.05). The inhibitory effect of zanubrutinib and temozolomide on the proliferation of OCI-Ly10 cell line was stronger than that of single drug. Conclusion Zanubrutinib-based combination therapy has good efficacy and controllable safety in elderly R/R PCNSL patients. The prognosis of elderly patients is poor, and the OS of chemotherapy patients is better than that of radiotherapy among the treatment options in the pre-BTKi era. Zanubrutinib inhibits cell viability and cell proliferation in ABC subtype DLBCL cell line OCI-Ly10.