Primary Central Nervous System Lymphoma Patients Research Articles

Autologous Stem Cell Transplantation (ASCT) Improves Survival Outcome in Primary Central Nervous System Lymphoma (PCNSL) in a Minority Rich, Underserved Inner City Population in the Real-World Setting

Primary CNS lymphoma (PCNSL) is rare and aggressive with distinct biological features and grim prognosis. Defining optimum treatment for PCNSL is challenging due to a dearth of randomized clinical trials. Autologous Stem Cell Transplant (ASCT) (also referred to as high dose chemotherapy with stem cell rescue) has been recommended by the National Comprehensive Cancer Network (NCCN®) as part of the treatment of PCNSL. There are no comprehensive studies of this disease and therapeutic modalities in real world settings. The aim of our study was to specifically compare the survival outcomes in patients receiving various induction and consolidation regimens used for the treatment of PCNSL. We sought to study patients with a primary diagnosis of primary CNS lymphoma, treated at our institution from June 2000 to April 2022. Fifty-three unique records of patients with PCNSL patients at Montefiore Medical Center/ Albert Einstein College of Medicine and 32 % (17) patients got ASCT. Mean age at diagnosis was 61 years. Baseline characteristics are in table 1. The most common induction regimen used was RMV (Rituximab, high dose Methotrexate and Vincristine) on 22 patients (41.5% of our cohort), other regimens used are in table 1. Whole brain radiation therapy (WBRT) was used on 2 patients for induction. Consolidation was used in 35 patients (66%). The most common consolidation strategies were: 1) high dose chemotherapy with autologous stem cell support (ASCT) in 17 patients (32%); 2) WBRT in 12 patients (22.6%); 3) Cytarabine (AraC) in 4 patients (7.5%). Eighteen patients (34%) did not receive consolidative therapy while one patient received both cytarabine and WBRT for consolidation. Patients receiving autologous stem cell transplantation were studied based on the conditioning regimen used. The most common regimens used were: 1) Thiotepa, Busulfan and Cytarabine (TBC) in 10 patients (62.5%); 2) BCNU, Etoposide, AraC and Melphalan (BEAM) in 5 patients (31.25%) and BCNU alone in one patient. Table 1 illustrates the comparison of survival outcomes of various consolidation regimens. The mean overall survival in those receiving ASCT was significantly better that patients receiving other consolidation modalities.(p=0.01, depicted in figure 1) We observed that one-year overall survival favored autologous stem cell transplant over WBRT (87% vs 76%). Out of all the patients receiving consolidation with ASCT 14/16 (87.5%) were alive at the time of the last visit [range time from transplant: 161 months - 2 months, median survival after ASCT 30 months]. Notably, WBRT had a remarkable benefit with 9/12 (75%) alive at last follow-up . Patients not receiving consolidative therapy had a worse outcome with 14/21 alive at last follow-up (66.6%) and a significantly worse OS compared to those receiving any consolidation. (58 vs 150 months, p = 0.01). The addition of Rituximab or procarbazine to induction regimens did not result in improved outcomes in survival (p=0.9 and p=0.23 respectively). In our minority rich urban cohort, we observed that autologous stem cell transplantation consolidation in primary CNS lymphoma resulted in an impressive survival of 87.5% after more than 10 years follow-up. Underutilization of this potentially curative strategy was observed with only 32% having access to autologous SCT. Investigation of the causes precluding transplant access is needed to improve outcomes in this disease. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Is It Possible to Omit Bone Marrow Biopsy in Diagnostic Workup in Patients with Newly Diagnosed Primary CNS Lymphoma? a Retrospective Analysis in the PET/CT Era

Background: Primary central nervous system lymphoma (PCNSL) is a rare and aggressive extra-nodal non-Hodgkin lymphoma (NHL) confined to the brain, eyes, leptomeninges, and spinal cord. More than 90% of patients belong to diffuse large B-cell lymphoma (DLBCL). The consensus around the extensive systematic staging in patients with suspected or proven PCNSL is still a matter of debate. Current diagnostic and staging guidelines recommend extensive workup to exclude systemic disease with computed tomography (CT) scan of the chest, abdomen, and pelvis, a bone marrow biopsy (BMB), and testicular ultrasonography in males. Whole-body 18F-fluorodeoxyglucose positron emission tomography (PET-CT) is currently considered optional in diagnostic workup in patients with presumed PCNSL. The utility of BMB in the era of PET-CT has been challenged in systemic lymphomas, but data are lacking for patients with PCNSL. Among patients with PCNSL, BMB is often normal or reveals low-grade lymphomas or just clonal B-cells. In rare instances, aggressive lymphoma involves both bone marrow (BM) and the central nervous system (CNS). However, the role of BMB in PCNSL patients in the PET-CT era is yet to be established. This study aimed to analyze whether BMB could be safely omitted in the diagnostic workup in patients with PCNSL of DLBCL histology without signs of systemic lymphoma on PET-CT scans. Methods: A comprehensive nationwide retrospective multicenter study with enrollment of patients from the referent medical centers in Denmark for treatment of PCNSL was performed. Patients included in the study were diagnosed between 2002 and 2020 and identified through the Danish Pathology Register. All patients with CNS involvement were potential candidates. Inclusion criteria were the following: 1) patients should be diagnosed with DLBCL in brain, eyes, leptomeninges, cerebrospinal fluid, and spinal cord; 2) have available BMB; and 3) have available PET-CT without signs of lymphoma outside of CNS. Patients with PCNSL and prior history of other lymphoma were also included in the study. Patients were excluded if they were diagnosed with systemic lymphoma or PCNSL other than DLBCL. Patients who did not have PET-CT and BMB performed or in whom this information could not be retrieved through medical records were also excluded from further analysis. Results: Of 1238 potential candidates identified through the Danish pathology register, only 300 patients fulfilled the inclusion criteria. Most patients were excluded due to a lack of information on PET-CT scans and BMB. All included patients had available BMB and no signs of systemic lymphoma on PET-CT. Of the included patients, 252 (84%) were diagnosed with PCNSL without a previous lymphoma diagnosis, while 48 (16%) had a previous history of lymphoma. The median age of patients was 68 years. There was a slight predomination of men (60%) compared to women (40%). Twenty-three (7.7%) patients were found to have discordant findings in BMB. However, none of these showed infiltration with DLBCL. The histologies included various low-grade lymphomas found in 17 patients (5.7%), monoclonal B-cells in 3 patients (1%), and smoldering multiple myeloma in one patient. Conclusion: In this retrospective study of 300 patients with PCNSL with PET-CT scans without signs of systemic lymphoma outside CNS, we found no cases with BM infiltration of DLBCL. A small proportion of patients with PCNSL have a discordant, often low-grade lymphoma in the bone marrow. With a sample size of 300, the chance of overlooking DLBCL infiltration in the BM is ≤ 1 % (95% CI). Therefore, the results of this, so far the most extensive study evaluating BMB in PCNSL in the PET-CT era, suggest that BMB can safely be omitted in patients with PCNSL of DLBCL histology and no signs of systemic lymphoma on PET-CT scans.

Noninvasive, Dynamic Risk Profiling of Primary Central Nervous System Lymphoma By Peripheral Blood Ctdna-Sequencing

Introduction: Primary central nervous system lymphoma (PCNSL) is a rare subtype of aggressive B-cell lymphoma restricted to the CNS. Despite the use of intensive chemotherapeutic regimens, relapsed or refractory disease (r/r) occurs frequently and depicts a major challenge. Response assessment is usually based on magnetic resonance imaging (MRI), but highly limited due to insufficient discrimination between scar and active tumor tissue. Furthermore, serial biopsies are often not feasible. Accordingly, there is a high unmet medical need for noninvasive risk profiling strategies in PCNSL. Methods: We applied circulating tumor DNA (ctDNA) sequencing to n=101 blood samples of n=47 patients. Peripheral blood was collected before (pre, n=47), during (mid, n=27) and after (post, n=22) treatment. Sequencing of ctDNA in cerebrospinal fluid (CSF) was performed in 5 patients. Our ctDNA sequencing approach encompasses a targeted gene panel covering >350 genes or genetic regions and an in-house developed bioinformatic pipeline. In the current version, our pipeline shows improved sensitivity and specificity over our previously published version (Sobesky S et al. Med. 2021;2(10):1171-1193.e11), mainly due to the addition of duplex barcode information. Results: The total amount of cell-free DNA (cfDNA) in plasma was generally low (mean 22.3, range 1.4-208.5 ng/ml) as compared to patients with systemic disease. We hypothesized that cfDNA fragment length profiles and their dynamic changes can inform on outcome in PCNSL as has been recently shown for other lymphomas (Meriranta L et al. Blood. 2022;139(12):1863-1877). To this end, we extracted fragment lengths distributions from all cfDNA samples and used principal component analysis to discern fragment length profiles representative of certain types of samples and remission status. Pre-treatment samples contained higher proportions of short cfDNA fragments (133-173 base pairs (bp)) compared to samples obtained mid-treatment, post-treatment, and healthy controls. In contrast, CSF samples were enriched with ultra-short cfDNA fragments (61-97 bp), which were almost absent in all other samples. The detection of single nucleotide polymorphisms (SNP) and small insertions or deletions (InDel) was challenging compared to our previously published experience with Hodgkin lymphoma (Sobesky S et al. Med. 2021;2(10):1171-1193.e11). Nevertheless, we detected mutations in most samples, including recurring mutations in PCNSL-associated genes such as MYD88, PIM1 and CD79, though at a lower frequency than expected. The mean baseline ctDNA concentration was 1.7 (range 0-2.8) log haploid genome equivalents (hGE)/ml plasma. Interestingly, the ctDNA concentration was markedly increased in CSF samples. Higher average mutated allele frequency (mAF) in a plasma sample at baseline was associated with reduced progression-free survival (PFS) and overall survival (OS). Patients with a mAF > 1% showed impaired PFS and OS compared to < 1%. No events were observed in patients with mAF < 0.5% (17% of all patients). MRI-based response evaluation indicated partial response in most patients both mid- and post-treatment and thus failed to predict outcomes. Therefore, we assessed mutation-based tracking of peripheral residual disease (PRD). Persistence of PRD during treatment was associated with impaired PFS (median 3.7 vs. 26.9 months, p < 0.0001) and OS (median 4.7 months vs. not reached, p = 0.0009). We hypothesized that dynamic detection of PRD might complement baseline risk stratification by mAF alone. In our final model, baseline low risk patients (mAF low) became high risk when PRD was positive, and baseline high risk patients (mAF high) became low risk when PRD turned negative during treatment. Strikingly, this classification was highly predictive of both PFS (median 9.3 vs. 26.9 months, p = 0.0004, Fig. 1) and OS (median 10.3 months vs. not reached, p = 0.0010). Conclusions: Surprisingly large differences in fragment length profiles between ctDNA in blood and CSF might yield insight into ctDNA characteristics of both compartments in the context of PCNSL and ctDNA biology in the privileged central nervous system compartment in general. Despite challenges in consistently detecting pathognomonic genetic alterations, assessment of ctDNA-based PRD and fragmentation patterns has the potential to significantly improve treatment guidance in PCNSL patients. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Impact of Double Expression of MYC and BCL-2 on Outcomes in Primary CNS Lymphoma: A UK Multicentre Analysis

Introduction Primary central nervous system lymphoma (PCNSL) is a rare B cell lymphoma with an aggressive course. Relapses remain common even with intensive immuno-chemotherapy treatment options such as MATRix and consolidation with autologous stem cell transplant (ASCT), and prognostic tools are limited. Although, double expressor status (co-expression of both MYC and BCL-2) is well established in systemic de novo DLBCL, its prognostic impact in PCNSL has been understudied. Here we evaluated the prognostic value of BCL-2, BCL-6, and MYC expression in a retrospective cohort of treated PCNSL patients diagnosed at 7 academic centres in the UK. Methods We performed this retrospective analysis on histologically-confirmed PCNSL patients diagnosed consecutively between 1st May 2015 and 31st May 2020. Treatment with a high-dose methotrexate-based chemotherapy regimen was a mandatory inclusion criterion. BCL-2 and MYC immunohistochemistry (IHC) protein expression data were collated from local diagnostic histology reports and double expressor (DE) status was defined as per WHO criteria (MYC: surface expression > 40% of cells and BCL-2: >50% of cells). Outcomes included response rates, progression-free survival (PFS) and overall survival (OS). Where available, diagnostic fluorescence in situ hybridisation (FISH) data was collected for BCL-2, BCL-6 and MYC loci translocations. Cox-regression for PFS and OS were used to determine baseline predictors of response and survival and to construct multivariable models for factors associated with outcome. Results In total, 242 patients were analysed. Key baseline patient characteristics and IHC data are summarised in Table 1. Median age was 65 years (IQR 56-71), 60% were male and 64% of patients had an ECOG performance status (PS) of 0-1. One hundred and seventy-four (72%) patients received treatment with MATRix chemotherapy; these patients were younger (median age 62 vs. 73 years, p< 0.01), had better baseline PS (PS ≤ 1: 75% vs. 37%, p< 0.01) and higher rates of consolidation with BCNU-thiotepa ASCT (58% vs. 7%, p< 0.01). Double expressor (DE) status was assessable in 169/242 (69%) patients. Reasons for absent DE status were missing IHC expression data (BCL-2: n=28; MYC: n=44) or IHC expression data not reported in line with WHO recommended criteria (BCL-2: n=45; MYC: n=7). In the DE-assessable cohort (n = 169 patients), 40% of patients had DE PCNSL, higher than estimates of DE prevalence in systemic DLBCL (reported rates between 20 and 30%). As only 40 cases (17%) underwent FISH assessment for concurrent MYC and BCL-2 loci translocation (double hit status), correlation between double hit and DE status was not possible. DE status was not associated with patient age at diagnosis, baseline PS or treatment received. With a median follow up of 1.7 years, 34% of patients relapsed and 45% died. Although single MYC or BCL-2 expression alone had no significant association with OS or PFS in the entire cohort, DE status was associated with significantly poorer PFS, and earlier relapse (median 0.86 years vs. 2.77 years; HR 1.61 (1.07 - 2.41); p=0.021) (Fig. 1). In a subgroup analysis restricted to patients treated with MATRix chemotherapy (n = 116 patients), there was a trend towards inferior PFS and OS, although this did not reach significance in a univariable analysis. However, the adverse prognostic impact of DE status on PFS was maintained in a multivariable analysis modelling age, baseline PS, treatment received, ASCT consolidation status and DE status both for the entire cohort (HR 1.75 (1.15 - 2.66); p<0.01) and the MATRix treated subgroup (HR 1.91 (1.08 - 3.36); p=0.03). A trend towards an association between DE status and OS was noted but did not reach significance in either a univariable or multivariable analysis. We observed no significant difference in PFS or OS between DE-PCNSL and non-DE-PCNSL patients who received MATRix and consolidation with ASCT, perhaps indicating that the adverse impact of DE status is modified by this treatment strategy, although the sample size was small (n=66). Conclusions In a large, retrospective cohort of PCNSL patients treated at 7 UK academic treatment centres, double expression of MYC and BCL-2 by IHC was associated with inferior PFS even in patients treated with MATRix chemotherapy. Validation of this finding in independent cohorts is warranted. ___ JO, CPF and KC share senior authorship Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

High-Dose Chemotherapy and Autologous Stem Cell Transplant in Elderly and Fit Primary CNS Lymphoma Patients - a Multicenter Study By the Cooperative PCNSL Study Group (MARTA study)

Introduction: High-dose methotrexate (HD-MTX) based induction chemo-immunotherapy followed by high-dose chemotherapy and autologous stem cell transplantation (HCT-ASCT) has been shown to be feasible and effective in younger and in selected elderly PCNSL patients. We aimed to investigate this treatment approach in patients > 65 years with newly diagnosed PCNSL in a multicentre study. Methods: This open-label, multicentre, single arm phase II study was conducted at 15 German centres (DRKS 00011932). Main eligibility criteria included newly diagnosed PCNSL, immunocompetence, age > 65 years, Eastern Cooperative Oncology Group Performance Status (ECOG PS) ≤ 2, and adequate organ function. Induction treatment consisted of two 21-day cycles of HD-MTX 3.5 g/m² (day 1), cytarabine 2 g/m² twice daily (days 2, 3) and rituximab 375 mg/m² before and after each chemotherapy with stem cell harvest after the 1st cycle. Patients not suffering disease progression subsequently received consolidation treatment with HCT-ASCT with rituximab 375 mg/m² (day -8), busulfan 3.2 mg/kg (days -7, -6), thiotepa 5 mg/kg/d (days -5, -4) and reinfusion of stem cells (day 0). Primary endpoint was progression-free survival (PFS) at 1 year by intention-to-treat (ITT). Secondary endpoints included overall survival (OS), treatment response and toxicities. Results: Between Nov 2017 and Sept 2020, we registered 57 patients. Five patients were excluded because of systemic lymphoma manifestation, absence of measurable radiologic lesion(s), inadequate renal function, ECOG PS >2 and deterioration before the start of study treatment. Finally, 52 eligible patients were included in the ITT population. Mean age was 72 years (range 65-80 years), 27/52 (51.9%) patients initially presented with an ECOG PS > 1. All patients started induction chemo-immunotherapy, 45 of 52 (86.5%) patients completed induction treatment. Thirty-seven of 52 (71.2%) patients proceeded to HCT-ASCT. Most common serious adverse events were infections, renal failure and (cerebro)vascular events, which mainly occurred during induction treatment. Overall, 22 (42.3%) patients died, 12 of whom (23.1%) without evidence of disease progression or relapse. Three (5.8%) patients died because of treatment-related complications, all of them during induction treatment. An additional patient died within 30 days after HCT-ASCT due to fatal viral pneumonia, main other non treatment-related causes of deaths were late infections and (cerebro)vascular events. Forty-one of 52 (78.8%) patients responded to induction treatment; 23 (44.2%) patients achieved a (unconfirmed) complete response and 11 (21.2%) patients a partial response 30 days after HCT-ASCT. After an estimated median follow-up of 23 months, PFS at 12 and 24 months was 57.7% (95% CI 43.2-69.7%) and 54.8% (40-67.4%), respectively; median PFS was 41.1 months (95% CI 6.7 to not calculable). Overall survival at 12 and 24 months was 63.1% (95% CI 48.4-74.7%) and 60.5% (95% CI 45.5-72.5%), respectively; median OS was 41.1 months (95% CI 10.3 to not calculable). Of those 37 patients undergoing HCT-ASCT, 2-year PFS and OS rates were 71.7% (95% CI 53.4-83.8%) and 80.8% (95% CI 63.8-90.3%), respectively. Conclusions: Feasibility and efficacy of HCT-ASCT in selected elderly patients with newly diagnosed PCNSL are confirmed in a multicenter setting with survival rates comparable to those of younger cohorts. Nevertheless, non-relapse mortality remains a major challenge in this vulnerable patient population emphasizing that standardized assessment of eligibility for intensive treatment is of utmost importance. This will be addressed in the upcoming randomized phase III PRIMA-CNS trial (DRKS00022768). Final data analysis is currently ongoing and will be presented in detail at the meeting.

Detection of Cell Free Tumor DNA in Plasma of Patients with Large B-Cell Lymphoma of the Sanctuary Sites By Digital Droplet PCR

Background: Primary central nervous system lymphoma (PCNSL) and primary testicular lymphoma (PTL) are rare mature B-cell lymphoproliferative diseases that arise at immunological sanctuary sites. Cytomorphology (CM) and flow cytometry (FCM) analysis of spinal fluid is diagnostic in about 15% of PCNSL. In the remaining patients, a tumor biopsy is necessary, which carries the risk of complications. Response assessment in PCNSL and PTL relies on imaging studies. However, MRI scans and 18F-FDG PET-scans often cannot differentiate between active tumor and scar tissue. Hence, there is a need for non-invasive tools to aid in diagnosis and help in response assessment. PCNSL and PTL are characterized by a high incidence of hotspot mutations in MYD88 and CD79B. Detection of these mutations in cell free DNA (cfDNA) might aid in diagnosis and follow-up of disease activity in patients with PCNSL and PTL. Digital droplet PCR (ddPCR) offers a robust inexpensive tool with a fast turnaround time allowing sensitive detection of such hotspot mutations. Methods: Plasma was available for a total of 26 patients (20 PCNSL and 6 PTL) in the OncoLifes biobank of the University Medical Center Groningen. All patients gave informed consent. Corresponding tumor samples were available for 17 cases (14 PCNSL and 3 PTL). A ddPCR was performed for MYD88 L265P and in case of sufficient cfDNA also for CD79B Y196X (Bio-Rad Laboratories, Hercules, USA). The ddPCR Assay for CD79B Y196X targets the mutation Y196H c.586T>C, Y196D c.586T>G, Y196S c.587A>C, Y196C c.587A>G, and Y196F c.587A>T. The cut off value for the allele frequency (AF) used was ≥0.5%. Results: The MYD88 L265P and CD79B Y196X mutations were detected in 9/14 (64.2%) and 2/13 (15.4%) of the PCNSL tissue samples. The two CD79B Y196X positive tissue cases had a concomitant MYD88 L256P. The MYD88 L265P mutation was detected in 2/20 (10%) cfDNA samples. The CD79B Y196X mutation was detected in 1/19 (5.2%) cfDNA samples; remarkably, this mutation was not detected in the corresponding tissue sample. In PTL, MYD88 L265P mutations were detected in 3/3 of tumor tissues and a CD79B Y196X mutation was detected in 1/2 of tumor tissues, which co-occurred with the MYD88 L265P. In PTL, 2/6 (33.3%) and 1/6 (16.6%) cfDNA samples were positive for MYD88 L265P and CD79B Y196X. Overall, hotspot MYD88 and/or CD79B mutations were detected in cfDNA in 5 /26 cases (18.4%) (Figure 1). Figure 1. ddPCR results of MYD88 and CD79BConclusion: We explored the feasibility of using a combination of two common hotspot mutations in MYD88 and CD79B in PCNSL and PTL plasma samples to aid in diagnosis and disease monitoring. The data presented show that the value of ddPCR for hotspot mutations in plasma of PCNSL and PTL patients is limited. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Orelabrutinib in Combination with Rituximab and Chemotherapy for Newly Diagnosed Aggressive B-Cell Lymphoma: A Multicenter, Single-Arm, Prospective Study

Keywords: Orelabrutinib, B-cell lymphoma, overall response rate Introduction Dysregulated B-cell receptor (BCR) signaling has been identified as an important feature of B-cell lymphomas. Inhibition of Bruton's tyrosine kinase (BTK), downstream of BCR, has demonstrated promising efficacy profiles in B-cell malignancies. Orelabrutinib is a newly developed BTK inhibitor with high selectivity for B-cell malignancies. This study was conducted to evaluate the preliminary efficacy and safety of orelabrutinib in combination with rituximab and chemotherapy for newly diagnosed aggressive B-cell lymphoma. Methods This was a single-arm, multicenter, prospective study in patients with clinical and histopathological confirmed aggressive B-cell lymphoma. The primary endpoints were investigator-assessed overall response rate (ORR) and complete response (CR) rate. Adverse events (AEs) were assessed in accordance with NCI CTCAE v4.03. Results A total of 42 patients with newly diagnosed aggressive B-cell lymphoma were enrolled from October 2020 to May 2022, including 28 diffuse large B-cell lymphoma (DLBCL), 12 primary central nervous system lymphoma (PCNSL), and 2 patients with high-grade B-cell lymphoma. The median age was 66.5 years (range, 35-86 years), and 23 (54.7%) were male. 66.7% of enrolled patients had stage III-IV disease. The median follow-up was 8.0 months (2.0-20.0 months). All the patients received orelabrutinib combined with rituximab and chemotherapy regimens. At data cutoff, 28 patients completed 6 cycles of treatment and were evaluated for therapeutic efficacy. Next-generation sequencing was performed and the genetic mutations included MYD88, BCL6, BCL2, CD79b, KMT2D, etc. All 42 patients were evaluable for toxicity. The toxic reactions were relatively mild, including grade 3 febrile neutropenia in 2 cases (4.8%), grade 3 neutropenia (2.4%), grade 3 thrombocytopenia (2.4%), and grade 3 leukopenia (2.4%). No other grade 3-4 non-hematologic AEs were reported. There was no dose modification due to AEs. The therapeutic responses were assessed. Among the 30 patients with DLBCL or high-grade B-cell lymphoma, 21 patients completed 6 cycles of treatment at data cutoff, with an ORR of 100%, and 15 (71.4%) patients achieved CR. The estimated 1-year overall survival (OS) and 1-year progression-free survival (PFS) rates were 100% and 94.1%, respectively. In addition, subgroup analyses were performed. Seventeen patients were non-GCB subtype, with a CR rate of 84.5%. Among the included DLBCL patients, 13 patients had MYC/BCL2 protein dual expression (DE), and the ORR and CR rate were 100% and 90.9%, respectively. Twenty-two patients were extra-nodal DLBCL, with a CR rate of 86.7%. The estimated 1-year PFS rate was 93.8%. Among them, 13 patients were non-GCB subtype, and 11 of them received 6 courses of treatment, with a CR rate of 81.8%. We further analyzed the treatment response of PCNSL patients. A total of 12 patients with newly diagnosed PCNSL were included in this study, with a median age of 57 years (range, 35-75 years) and 7 (58.2%) patients were male. Ten (83.3%) patients were non-GCB subtype. Seven patients completed 6 courses of treatment, with an ORR of 100%, and 4 patients achieved CR. Conclusions The preliminary results of this study suggested that orelabrutinib in combination with rituximab and chemotherapy may be a well-tolerated and effective regimen in newly diagnosed aggressive B-cell lymphoma patients. A larger sample size and longer follow-up time are needed in the future to validate this conclusion. Next-generation sequencing results are expected to provide additional explanations for differential treatment responses. Disclosure: No relevant conflicts of interest to declare.

Orelabrutinib, Rituximab, and High-Dose Methotrexate (HD-MTX) in Newly Diagnosed Primary Central Nervous System Lymphoma (PCNSL): A Retrospective Analysis on Efficacy, Safety, and Biomarker

Introduction: PCNSL is a rare malignant tumor arising in the brain, spinal cord, eyes, or leptomeninges. HD-MTX-based regimens remain the first option for newly diagnosed PCNSL because of high response rates as demonstrated by numerous studies (Qing et al. Cancer Manag Res 2021). Bruton's tyrosine kinase (BTK) is a crucial part of the B-cell receptor signaling pathway, and BTK inhibition has been proven effective in treating CLL and other B-cell lymphomas (Yoshitaka et al. Neuro-Oncology 2021). Orelabrutinib is a newly developed BTK inhibitor with high selectivity and a high concentration in the cerebrospinal fluid (Zhang et al, EHA 2022). Recent evidence has shown the efficacy and safety of orelabrutinib in PCNSL (Wu et al., Invest New Drugs 2022). Therefore, we conducted a retrospective study of clinical outcomes in newly diagnosed PCNSL patients (pts) treated with orelabrutinib combined with rituximab and HD-MTX (RMO) regimen in routine clinical care. Methods: This retrospective cohort included the pts (aged 18-80 years) with newly diagnosed PCNSL who received at least 2 cycles of RMO regimen (rituximab 375 mg/m2 iv day 1; MTX 3.5 g/m2 iv day1; orelabrutinib 150 mg qd po; 3 weeks per cycle) as the induction therapy in a real-world setting between May 2021 and June 2022. It was proposed to receive orelabrutinib monotherapy as maintenance after RMO therapy when deemed necessary. 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: Thirty-Four pts with newly diagnosed PCNSL (20 male; 24 non-GCB subtypes) were included, with a median age of 58.5 years (range: 30-79). Four (11.8%) pts had an ECOG performance status of ≥3. All the pts (100%) achieved certain responses (Figure 1) with a complete response in 21 pts (61.8%). Eighteen (52.9%) pts completed 6 cycles of RMO as induction, with an ORR of 94.44% (17/18) and CR rate of 88.89% (16/18) at the 6th cycle assessment. As of the cut-off date (June 30, 2022), 8 pts received orelabrutinib maintenance therapy and had a CR status. Median PFS was not reached (95% CI, 7 months-not reached; Figure 2), with a 6-month PFS rate of 97.0% (95% CI, 91.3%-100.0%). Median OS was not reached either. In 22 pts who were available for gene alterations profiling, 18 pts (81.8%, 18/22) had an MYD88 mutation and achieved an ORR of 100% (CR, 55.6%). Four of these 18 pts were found to have a mutation in CD79B simultaneously. Plasma and CSF samples were collected from 5 patients at 2 hours after 15-day consecutive administration of orelabrutinib. The median CSF concentration of orelabrutinib was 21.6 ng/ml (range, 15.9-48.5), and the median CSF/plasma free ratio was 58.6% (range, 38.6%-82.5%). All these 5 pts achieved a response (3 CR; 2 PR). Six of 34 (17.65%) pts experienced adverse events (AEs). The most common AE was white blood cell count decreased (8.82%). Only 2 (5.88%) pts experienced 4 ≥grade 3 AEs, including white blood cell count decreased, anemia, platelet count decreased, and alanine aminotransferase increased. No treatment-related death occurred. Conclusion: This retrospective data suggested that orelabrutinib combined with RM had an encouraging anti-tumor activity in newly diagnosed PCNSL pts, with a toleratable safety profile. A prospective clinical trial is on the way to confirming this finding, and the results will be publicly disclosed after its completion. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Zanubrutinib, Lenalidomide, Rituximab, Temozolomide and Methotrexate (RLZT±MTX) As First-Line Treatment for Newly Diagnosed PCNSL: A Prospective, Open-Lable, Multicenter Clinical Trial

Backgroud: Primary central nervous system lymphoma (PCNSL) represents approximately 2% of all primary central nervous system tumors and 4% to 6% of all extranodal lymphomas. The incidence of PCNSL has been increasing in recent years, and the median age at diagnosis was 65 years old. Most PCNSLs are diffuse large B-cell lymphoma (DLBCL; 90%-95%). PCNSL-DLBCL is a rare and highly aggressive lymphoma, due to its characteristics and special involved sites，previous treatment effect is disappointing with poor prognosis. Aim: This study aims to evaluate the clinical efficacy and safety of Zanubrutinib combined with Lenalidomide, Temozolomide and Rituximab monoclonal antibody ±Methotrexate (RLZT±MTX) as first-line treatment for primary central nervous system lymphoma, especially in elderly patients who cannot tolerance to intensive chemotherapy. Methods: The prospective, multicenter, open-label study planned to enroll 40 patients(Registration number:ChiCTR2000039485). Group A (RLZT+MTX) :eligible 20 young patients were ≤65 years, with normal kidney function. Patients in arm A were treated with regimen 1 and 2 alternately, each 3 courses, A total of 6 courses; Group B (RLZT) :eligible 20 elderly patients were >65 years or ≤65 years frail patients or patients with kidney dysfunction, regimen 2 was used for a total of 6 courses. Regimen 1: high-dose MTX (3.5g/m2) every 28 days; Regimen 2: RLZT (Rituximab 375mg/m2 IV D1, Lenalidomide 15mg/m2 D1-21, Zanubrutinib 160mg bid D1-21, Temozolomide 150mg/m2 Po D1-5) every 28 days. Note: 1. In group A, if patients who did not have a CR or PR after 6 cycles of the above regimen then the whole-brain radiotherapy (WBRT) was recommended; If patients achieved a CR or PR, auto-HSCT consolidation therapy was feasible; If the patient is not willing to transplant, enter single-agent oral Zanubrutinib to maintain until disease progression or intolerance.2. In group B, if patients who did not have a CR or PR after 6 cycles RLZT then the whole-brain radiotherapy (WBRT) was recommended, if patients achieved a CR or PR, maintain Zanubrutinib until diseaseprogression or intolerance. Results: The data cut-off date was June 30, 2022, totally 24 patients enrolled in this clinical trial，both groups had 12 patients(Table 1). The ORR in the 24 PCNSL pts was 79.2%, with 9 (37.5%) complete responses (CR) and 10 (41.7%) partial responses (PR), in addition, 2 (8.3%) stable disease (SD) and 3 (12.5%) progressive disease (PD) were observed. The ORR was 66.7% (CR:16.7%, PR 50%) in the RLZT+MTX group and 91.7% (CR:58.3%, PR 33.3%) in the RLZT group. The median PFS and OS were not achieved in total patients，and the estimated 18-months OS and PFS were 95.8% and 78.2%, respectively. Similarly, The median PFS and OS were not achieved in both groups，estimated 18-months OS was 91.7% in the RLZT+MTX group and 100% in the RLZT group. The estimated 18-months PFS was 81.5% in the RLZT+MTX group and 80% in the RLZT group (Figure1). Overall, 50%patients had experienced hematologic toxicity. Only 1 patient had grade ≥3 thrombocytopenia event and 1 patient had grade ≥3 leukopenia event. The overall incidence of non-hematologic toxicity was 50%, including gastrointestinal reactions, rash, liver and kidney damage, but only one patient had≥3 grade AE (rash). In addition, pneumonia was reported in 16.7% (4/24) of the patients, but no deaths were due to adverse events (Table 2). Conclusions: This study showed that RLZT+MTX was an effective and safety first-line treatment for PCNSL patients. It is worth noting that in elderly patients who cannot tolerate high-dose chemoradiotherapy, RLZT shows a promising prospect. Keywords: Primary central nervous system lymphoma, Zanubrutinib, first-line treatment Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

A Prospective Study of Methotrexate in Combination with Ibrutinib and Temozolomide (MIT) in Newly Diagnosed Primary CNS Lymphoma

Background: Primary central nervous system lymphoma (PCNSL) is a rare non-Hodgkin lymphoma ,High-dose methotrexate (HD-MTX) systemic chemotherapy is considered as the first-line standard therapy for PCNSL, but the ORR of HD-MTX-based chemotherapy was 60%~70%.The activation of the B-cell receptor pathway has been identified as a key mechanism of PCNSL and BTK inhibitor is a promising agent. Here we aimed to investigate the safety and efficacy of induction treatment, high-dose methotrexate in combination with ibrutinib and temozolomide (MIT) in newly diagnosed PCNSL. Methods: This open-label， single-arm, multi-center phase II prospective study(NCT04514393) was designed to enroll 33 patients , and 25 patients have response (approx 75%), the MIT treatment would be considered effective. Eligible patients were ≥18 and ≤75 years of age with adequate organ function, with at least one measurable lesion. The MIT induction treatment included six cycles of high-dose methotrexate (HD-MTX, 3.5 g/m2, every three weeks), ibrutinib (560 mg/d, after HD-MTX clearance), and temozolomide (150 mg/m2 d1-d5, every three weeks). After the completion of the six cycles of MIT induction treatment, ASCT consolidation (only for patients < 65 yr) and daily ibrutinib (560 mg/d) were administered up to two years, or until disease progression, intolerable toxicity, or death. Treatment response was evaluated by brain MRI and FDG-PET and/or cerebrospinal fluid (CSF) examination every two cycles of the induction MIT treatment. The primary endpoint was the overall response rate (ORR) of the 6 cycles of MIT induction treatment for PCNSL evaluated by investigator. The safety of the treatment were also investigated. Baseline and sequential CSF/plasma samples were collected and underwent targeted next-generation sequencing (NGS). Results: Between July 2021 and July 2022, thirty-one newly diagnosed PCNSL patients with no prior therapy were enrolled and 28 patients accepted at least 2 cycles of MIT treatment. The median age of the patients was 53 yr (range: 27-75) and15/28 (53.6%) were male. By data cutoff, 12/28 (42.9%) patients had completed six cycles of treatment, 9/28 had completed 4 cycles of treatment, and 7/28 had completed 2 cycles of treatment. The ORR was 92.9% (26/28), and CR rate was 67.9% (19/28). Among 12 patients had completed 6 cycles of treatment, 11/12 (91.7%) patients achieved CR, 1 patient achived PR. Among 9 patients had completed 4 cycles of treatment, 4 (44.4%) achived CR, 3/9 (33.3%) achived PR. Among 7 patients had completed 2 cycles of treatment, 4 (57.1%) patients achieved CR and 3 (42.8%) pateints achived PR. The mutation profiles of dynamic CFS and plasma ctDNA were collected and analyzed. The most commonly mutated genes in CSF were PIM1, MYD88, BTG2, CD79B, IRF4, and ETS1. The Cerebrospinal fluid protein (CSF-TP) and CSF cfDNA concentration (ng/ml), ctDNA MAF, and ctDNA concentration (hGe/ml), MAF,and hGe/ml were positively correlated. We compared gene profiles of patients in response and no response. KMT2D gene mutations were more commonly detected in patients with progression disease compared to patients responding to treatment (P=0.03). Interestingly, detectable baseline plasma ctDNA and post-treatment CSF ctDNA were significant associated with progression disease (P=0.03, P=0.004, respectively). This clinical trial is still on going. Conclusions: The MIT induction treatment could achieve higher responses compared with HD-MTX-based chemotherapy in newly diagnosed PCNSL patients and the adverse events are manageable.

Phase Ib/II Study of Rituximab, Lenalidomide and Methotrexate Followed By Lenalidomide Maintenance in Patients with Newly Diagnosed Primary CNS Lymphoma: The Remla Trial

Purpose: We evaluated the tolerability and efficacy of adding lenalidomide to a rituximab and methotrexate combination (R2-MTX) regimen, followed by lenalidomide maintenance as a first-line treatment of patients with primary central nervous system lymphoma (PCNSL). Patients and methods: This multicenter prospective phase Ib/II study, enrolled immunocompetent patients aged 18-75 years with untreated PCNSL. The phase I study increased lenalidomide dose from 15 to 20 to 25 mg. Patients were treated with rituximab 375 mg/m2 and methotrexate 3.5 g/m2 on day 1 and lenalidomide daily for 14 days every 3-week cycle. After 6 cycles of the R2-MTX regimen, responsive patients received lenalidomide maintenance therapy(lenalidomide 25 mg daily for 21 days every 4-week cycle for 2 years).ASCT was optional in eligible patients before lenalidomide maintenance. The primary phase I endpoint was the maximum tolerated dose of lenalidomide. The primary phase II endpoint was the 2-year progression-free survival (PFS). Results: Eleven patients were enrolled in phase Ib of the study. No Dose-limiting toxicities were observed, and the recommend phase II dose of lenalidomide was 25mg. In phase II, 23 patients were treated. The median follow-up period was 14.2 months (range, 8.0-33.4), the estimated 2-year PFS and OS were 61.5%(95% CI 50.7-91.8 ) and 81.7%(95% CI 57.4-92.9), respectively. In the PR2D group, the objective response rate was 92.%, and estimated 2-year PFS and OS were 78.5%(95% CI 50.7-91.8) and 90.4%(95% CI 66.8-97.5). Compared with historical controls in our center, 2-year PFS were significantly improved (P = 0.0088). Hematological toxicities, GI symptoms and infection were the most frequent adverse events, and grade 3/4 toxicities were seen in 62.5% of patients. Quality of life was stabilized during the lenalidomide maintenance phase. Conclusion: R2-MTX regimen supported the integration of lenalidomide to HD-MTX in induction therapy and maintenance as front-line treatment PCNSL patients with good safety, response rate and 2-year PFS. More importantly, the REMLA trial suggested lenalidomide maintenance could be an option instead of WBRT/ASCT consolidation even in younger patients. Randomized trials that incorporate this regimen are needed to determine its efficacy compared with other strategies. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Preliminary Result of 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 diffuse large B-cell lymphoma (DLBCL). High-dose methotrexate (HD-MTX)-based regimen is the first-line treatment of PCNSL, with or without the anti-CD20 antibody rituximab, remaining to be suboptimal due to unstable response and short effective remission time. Genetic alterations often occur in the chronic active B-cell receptor signaling featured by MYD88 and CD79B which mediate the response to BTK inhibition (BTKi) in PCNSL. 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 (ClinicalTrials.gov identifier: NCT05036577). It was planned to enroll 12-15 patients with newly diagnosed PCNSL to the regimen of orelabrutinib and MTX combined with the fixed dose of rituximab(R) and dexamethasone(D). 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/m2 on day 1), dexamethasone (10-15mg on d1-d4), MTX (d2, 3.5g/m2 or 5g/m2), 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. Baseline tissue/CSF samples and sequential CSF/plasma samples were collected for targeted NGS and pharmacokinetics evaluation as exploratory objectives. Results: Eight patients were enrolled from October 2021 to June 2022 as the preliminary analysis set. The median age was 62 year (range: 43-73) and six patients were male. All the patients with histologically confirmed DLBCL (6 non-GCB subtypes and 2 GCB subtypes) had completed at least one cycle of ORMD treatment and were evaluable for DLT. The median cycle of ORMD was one (range: 1-7). No DLT occurred among first three patients in cohort 1 (Orelabrutinib: 150mg/MTX: 3.5g/m2) and dose escalation was allowed to cohort 2 (Orelabrutinib: 200mg/MTX: 3.5g/m2). 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/m2). No Gr 4 AE had been observed. The most common adverse events were lymphopenia (Gr 3 in 4 case) and hyperglycemia (Gr 3 in 1 case). No atrial fibrillation, hypertension, or bleeding was observed by the cut-off date. The study is ongoing. Further results will be updated as data becomes mature. Conclusions: ORMD regimen preliminarily demonstrated predictable and manageable safety profile in newly diagnosed PCNSL patients with 200mg/d orelabrutinib and 3.5g/m2 MTX to date. MTD contour not reached and further evaluation continues. Longer follow-up is needed regarding efficacy, biomarker, and more safety data Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Preliminary Results of Penpulimab Combined with RMA (rituximab, methotrexate, and cytarabine) for Newly Diagnosed Primary Central Nervous System Lymphoma

Background: Primary central nervous system lymphoma (PCNSL) has been classified as large B-cell lymphomas (LBCL) of immune-privileged sites according to the 5th edition of the World Health Organization (WHO) Classification. The efficacy of high-dose methotrexate as a first-line treatment was suboptimal with a short effective remission time and low response rate. The recent discovery of the frequent copy number alterations in 9p24.1/PD-L1/PD-L2 and increased expression of PD-L1 in PCNSL provide the rationale to evaluate the efficacy of PD-1antibody in PCNSL. Methods: NCT05347641 is an ongoing Phase II, single-center, single-arm, open-label study, aimed to enrolled an estimated 23 newly diagnosed PCNSL patients. Enrolled patients first received the Pen-RMA induction treatment, including rituximab 375 mg/m2, d0; methotrexate 3.5g/m2, d1; cytarabine 1‒2g/m2, q12h, d2-3; penpulimab (an anti-PD1 antibody of IgG1 isotype) 200 mg, d5; 21d/cycle, for six cycles. Patients aged 60 years or younger, with complete response (CR)/unconfirmed complete response (CRu)/partial response (PR) after six cycles of induction treatment then underwent autologous stem cell transplantation (ASCT) before maintenance treatment. The maintenance regimen was administered based on patient response to ASCT, or to induction therapy for patients aged 60 years or older. Patients who achieved CR after ASCT or induction therapy then received 8 cycles of penpulimab as maintenance therapy, and those with PR after ASCT or induction therapy received whole brain radiotherapy (WBRT) combined with 8 cycles of penpulimab as maintenance. Treatment response was evaluated by brain MRI and FDG-PET and/or cerebrospinal fluid (CSF) examination every three cycles of the induction treatment. The primary endpoint of this study was two-year progression-free survival rate. Baseline tissue samples and sequential CSF or plasma samples were collected for targeted next-generation sequencing (NGS) at Nanjing Geneseeq Technology Inc. Results: Between April, 2022 and July, 2022, eleven newly diagnosed PCNSL patients has been enrolled. Treatment response was evaluable in eight patients. At the interim assessment point (after 3 cycles), six patients have achieved CR, with an overall response rate of 75.0%. Of these, three have completed 6 cycles of treatment and all achieved CR at the final assessment (Figure A). Adverse events of grade 3 or 4 occurred in five patients, including three neutropenia (27.3%), one thrombocytopenia (9.1%), and one renal dysfunction (9.1%). In the baseline samples, PIM1, MYD88L265P, and CD79B were the most common mutations, with a more comprehensive genomic landscape revealed by CSF than by blood (Figure B). All nine NGS-tested patients were classifier into the non-GCB subtype by the COO classification and the MCD subtype by the LymphGen classifier. CSF-based ctDNA monitoring was performed in two patients after 6 cycles of treatment. P01 had confirmed CR with ctDNA clearance in CSF. P07, was assessed as CR after 6 cycles, but the CSF ctDNA remained positive. This patient is currently receiving maintenance treatment and is being closely monitored for potential disease relapse. Interestingly, P02 and P04, who were PD and SD at interim evaluation, respectively, had markedly more mutations detected in their baseline plasma samples, indicating a poor prognosis (Figure A). Conclusion: The induction treatment of Pen-RMA has shown excellent responses in newly diagnosed PCNSL patients with mild hematologic toxicity. Our preliminary results also suggested that CSF-based ctDNA could facilitate diagnosis when tissue was inaccessible and show higher sensitivity than imageology in assessing the depth of remission. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Disparities in Somatic Mutations and Outcomes in Primary Central Nervous System Lymphoma Comparing Patients of Hispanic and Non-Hispanic Ethnicity

Background: Primary central nervous system lymphoma (PCNSL) is characterized by frequent MYD88 L265P activating mutations, biallelic CDKN2A loss, and mutations in CD79B, PIM1, and CARD11. However, the extent to which mutations vary by ethnicity is unknown. The purpose of this study is to describe differences in genetic mutations and survival between PCNSL patients of different ethnicities. Methods: We retrospectively analyzed patients ≥ 18 years with PCNSL diagnosed between January 2011- December 2020 and treated at UCSF-Fresno and University of Oklahoma. Next generation sequencing was performed on Formalin Fixed Paraffin Embedded tissue. We examined mutations in 434 genes by DNA analysis and 1408 genes by RNA analysis. Sequencing was performed using an Illumina NextSeq 550 system platform. The clinical data including age, sex, ethnicity, race, ECOG performance status, number and location of lesions, HIV status, LDH, protein in the CSF, and treatment regimens were reviewed. Treatment response was assessed by MRI using the international consensus group response criteria. Comparison of patient characteristics and rate of genetic alterations between Hispanic and Non-Hispanic patients was done using the Fisher exact test or Chi-square test. Time-to-event analyses were conducted using the Kaplan-Meier method and were compared by a log-rank test. Univariate analyses were performed via the Cox proportional hazards model. Analysis was performed with STATA version 16.0. Results: Among the 51 patients analyzed, the median age was 61. 54% were males and 43% were Hispanic. 13% had HIV, 27% had deep brain involvement, and 58% had non-germinal center (non-GC) type per Hans Criteria. 81% of Hispanic patients had non-GC vs 41% non-Hispanic (P=0.006). There was no statistically significant difference in age, performance status, HIV status, deep brain involvement, or CSF involvement between Hispanic non-Hispanic patients. 90% of patients received systemic chemotherapy for initial treatment, with 41% receiving high dose Methotrexate, Rituximab and Temozolomide. No patients received autologous stem cell transplant in first remission. 90% Hispanic Vs 89% Non-Hispanic received systemic chemotherapy (P=0.447). 29 patients (56%) achieved complete response (CR)/unconfirmed complete response (CRu). 2-year progression-free survival (PFS) was 67.4%, and 2-year overall survival (OS) was 55% for all patients. 177 genetic alterations were detected with the most common being MYD88, CD79B, TET2, PIM1, ETV6 and TP53 (table). Hispanic patients, compared with non-Hispanic patients, had a lower rate of MYD88 mutation (40.9% vs 72.4%, P=0.024) and TP53 mutation (0.0% vs 24.1%, P=0.001). 2-year PFS in Hispanics was 40% vs 30% in non-Hispanics (P=0.526) and 2-year OS in Hispanics was 0.63% vs 0.33% in non-Hispanics (P=0.05). In univariate analysis, age and genetic alterations (MYD88, CD79B, TET2, PIM1 and ETV6) were not associated with significant differences in 2-year PFS or OS. Performance status (ECOG ≤ 2), negative CSF cytology, and treatment with multi-agent chemotherapy rather than high dose Methotrexate alone were associated with better 2-yr OS. Conclusions: We identified highly recurrent genetic alterations in PCNSL. Our data suggest that some heterogeneity in the most frequent mutations in PCNSL may be related to ethnicity. Hispanic patients in our study have better 2-year OS; however, the data is limited by the retrospective analysis and the small patient number. Further studies on a larger patient population are warranted to evaluate genetic heterogeneity in different ethnic groups and effect of ethnicity and socio- economic status on outcomes in patients with PCNSL Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Next-Generation Sequencing of Newly-Diagnosed Primary CNS Lymphoma Reveals Alterations in BTG1, ETV6, and 6p Are Associated with Chemoresistance and Inferior Progression-Free Survival

Introduction: There is a significant unmet need for the development of reliable genetic biomarkers that identify patients with newly-diagnosed primary CNS lymphoma (PCNSL) who are at high risk of progression, both during standard methotrexate-based induction as well as delayed progression after receipt of dose-intensive consolidation. Currently, little is known about the genetic subtypes of PCNSL and the basis for differences in chemo-immunotherapeutic response. We hypothesized that an integrated clinical-genomic analysis may reveal new determinants of tumor progression and may ultimately guide a precision medicine-based approach to the selection of effective treatment regimens. Methods: We performed targeted next-generation sequencing of 529 pan-cancer genes of pre-treatment, formalin-fixed, paraffin-embedded tumors from 52 patients with CNS diffuse large B-cell lymphoma. We identified structural variants including single nucleotide variants, small insertions and deletions, and copy-number alterations. Clinical records were retrospectively reviewed to determine patients' baseline characteristics, IELSG index, and progression-free survival (PFS). 44 EBV-negative PCNSL patients treated with methotrexate, temozolomide, rituximab (MTR) induction with adequate genomic samples were available for complete analysis. Statistical testing was performed using R. Results: We identified three candidate genomic alterations that were significantly associated with chemotherapy resistance in PCNSL: (1) Alterations at 6p21.3, including both copy neutral loss of heterozygosity (CN LOH) at the HLA Class I (HLA-A, B, C) and Class II loci (HLA-DR, DP, DQ, TAP1) as well as homozygous deletion of HLA Class II; (2) Mutations of tumor suppressor genes BTG-1 and ETV6 (Fisher's exact, p < 0.01). Overall, these genomic alterations were detected in 18 out of 19 progression events in the cohort (Fisher's exact, p < 0.001). 7 of 9 tumors with 6p CN LOH also contained mutations at BTG-1 and/or ETV6. Kaplan-Meier survival analysis shows three subgroups stratified by alteration type with distinct PFS outcomes (Figure 1). The subgroup with either CN LOH or homozygous deletion at 6p had the earliest progression, followed by the subgroup with mutations at either BTG-1/ETV6 and no 6p CN LOH or homozygous deletion, compared to no alterations at these 3 loci (Log-rank, p < 0.01). Patients with hemizygous loss at 6p exhibited a trend towards worse outcome compared to no 6p loss. Furthermore, multivariate Cox proportional hazard analysis demonstrated a statistically significant 2.7-fold increased risk of progression with 6p CN LOH/homozygous deletion or mutations involving BTG-1/ETV6 (Table 1). While etoposide-cytarabine consolidation and maintenance lenalidomide were each significantly associated with a decreased risk of progression, age at diagnosis, Karnofsky performance status, intraocular disease status, and IELSG index were not significantly associated with PFS. Conclusions: Through harmonizing clinical and next-generation sequencing data, in this retrospective analysis we identify pathogenic alterations involving BTG-1 and ETV6, as well as major alterations at 6p21.3, that correlated with accelerated disease progression and an early tumor resistance phenotype in PCNSL. While 6p loss has been identified as a mechanism of tumor immune escape in PCNSL, our results suggest that 6p CN LOH may be a novel mechanism associated with early progression. Of note, in a parallel investigation using patient-derived CNS lymphoma tumor cells engrafted in a murine orthotopic xenograft model, we have demonstrated that lenalidomide significantly induces transcription of 6p21.3 genes involved in antigen presentation and immunomodulation, including HLA-A, TAP-1, and lymphotoxins. Taken together, 6p21.3 copy number loss, in particular CN LOH and homozygous deletion, as well as mutations in BTG-1 and ETV6 may be a promising biomarker set, potentially useful in risk stratification in clinical trials as well as to identify high risk patients more likely to derive benefit from lenalidomide. Prospective validation studies are planned to confirm these results. Supported by NCI. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Initial Treatment Response Is Prognostic and Predictive of Relapse Patterns: Outcomes of >500 Patients Treated for Primary CNS Lymphoma

Introduction: Given concerns for neurotoxicity of standard dose (SD) whole brain radiotherapy (WBRT) after high-dose methotrexate (MTX), consolidation for primary CNS lymphoma (PCNSL) has evolved to either autologous hematopoietic cell transplantation (AHCT) or reduced dose (RD; ≤24Gy) WBRT with cytarabine. We sought to evaluate factors influencing consolidation approach and survival outcomes by consolidation strategy. For a disease that has historically been considered multifocal, we analyzed patterns of relapse in a large cohort of contemporarily treated patients. Methods: PCNSL patients treated at Memorial Sloan Kettering from 1983-2020 were analyzed. Initial site was determined by T1 post-contrast-enhancing MRI. Patients were categorized by response (complete/unconfirmed [CR/CRu], partial [PR], stable, progression [POD]) to induction and consolidation (AHCT, RD vs SD WBRT, cytarabine, other). Factors impacting consolidation strategy were assessed by multinomial logistic regression models. Site of initial progression was categorized as local (involving/adjacent to initial site) vs distant intraparenchymal, leptomeningeal (CSF and/or MRI), or other. Cumulative incidence of local failure was assessed with death as a competing risk. Progression-free survival (PFS) was assessed from consolidation start with Kaplan Meier and proportional hazards. Results: Of 645 patients, 559 were eligible for inclusion (diffuse large B-cell, sufficient data, ≥1 MRI response assessment). Median follow-up was 7.4 years. From diagnosis, median PFS was 2.2 years and median overall survival (OS) was 5.7 years. Median age was 63 years (IQR 54-72), and most (57%) were recursive partitioning analysis (RPA) class 2 (age≥50, KPS≥70). Most had supratentorial (420, 81%), multifocal (274, 53%), bilateral (224, 43%), and deep structure involvement (314, 56%). Nearly all received MTX-based induction (532, 95%); common regimens were rituximab, MTX, procarbazine, vincristine (R-MVP; 257, 46%) and MVP (144, 26%). Most (403, 72%) responded to induction (305 [76%] CR/CRu, 98 PR [25%]). 385 patients received consolidation: 116 (21%) WBRT, of which 55 (47%) had RD; 80 (15%) AHCT; 170 (31%) cytarabine; 19 (3%) other. Consolidation approaches evolved over time (SD WBRT 65% in 1980s-1990s vs 3% in 2000s-2020s, RD WBRT 0% in 1980s-1990s vs 18% in 2000s-2020s, AHCT 4% in 1980s-1990s vs 25% in 2000s-2020s; Fisher's exact test, p-value <0.001). RPA and induction response were significantly associated with consolidation approach, while baseline tumor size and leptomeningeal involvement were not. Patients with higher RPA were less likely to undergo AHCT than RD WBRT (RPA 3 vs 1, HR 0.15 [0.04, 0.53], p=0.003). Compared to patients with CR, those with PR were more likely to receive SD WBRT (HR 4.56 [1.70, 12.3] p=0.003) and less likely to receive AHCT (HR 0.34 [0.13, 0.93] p=0.036) than RD WBRT. Of the 385 patients consolidated, 352 (91%) achieved CR/CRu, of whom 145 (41%) later relapsed. Most relapses after CR to consolidation were multifocal, non-local (1- and 5-year cumulative incidences: 43% and 86%, respectively) as opposed to unifocal local (8% and 16% at 1- and 5-years) or unifocal non-local (31% and 70% at 1- and 5-years). Upon controlling for diagnosis year, induction regimen, RPA, consolidation approach, and the interaction between consolidation and RPA, there was no significant difference in PFS or OS by consolidation strategy (AHCT vs RD WBRT: PFS HR 1.25 [0.31, 5.05], p=0.755; OS HR 0.88 [0.36, 2.19], p=0.788; Figure). Among those who did not achieve CR to consolidation (POD n=16, PR n=14, stable n=4), patients who progressed had the worst prognosis (median OS: POD 1.04 years, PR 2.7 years, Stable 6.1 years; p=0.005) with 6 (38%) experiencing local only progression. Of the 81 patients with POD on induction, 46 (57%) had local only progression. Conclusion: In a large PCNSL cohort, modern consolidation (AHCT, RD WBRT) achieved similar survival outcomes upon controlling for clinical variables in patients who achieved CR to consolidation. Performance status, age, and response to induction influenced consolidation strategy and outcomes, suggesting a role for further personalization. While delayed relapses after achieving CR to consolidation were often multifocal and non-local, early progression patterns in refractory patients (with many remaining localized) may suggest a role for focal RT for residual disease. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

DDEL-15. METHOTREXATE AREA UNDER THE CURVE IN PRIMARY CNS LYMPHOMA

Abstract INTRODUCTION There is consensus that high-dose methotrexate-based (HD-MTX) chemotherapy is the first line treatment for primary central nervous system lymphoma (PCNSL) but there is no consensus on drug dosing and duration. Area under the curve of Methotrexate (MTX-AUC) is a measure of exposure, and we hypothesize that a high MTX-AUC is associated with improved overall survival (OS) and progression free survival (PFS).Method: This retrospective study was approved by the institutional review board. HIV negative PCNSL patients who received Rituximab and HD-MTX at our institution from 2002-2020 were included. HD-MTX dose ranged from 1.2 gm/m2-8 gm/m2 based on creatinine clearance. MTX-AUC was calculated using mtxpk.org. OS and PFS were analyzed using Kaplan-Meier method and Cox proportional hazard regression. Result: 34 PCNSL patient’s charts (mean age: 67 yrs ± 15, 22F/12M) were reviewed. The mean MTX dose (5313 mg/m2) strongly correlated with the mean MTX-AUC (3648 μmol*l−1h, range: 698 – 6634). Patients with MTX-AUC &amp;lt; 3648 μmol*l−1h median PFS is 44.6 months (95% CI: 3.8– non-estimable), not significantly different from patient with MTX-AUC &amp;gt; 3648μmol*l−1h (PFS: 53.2 months, 95% CI: 4.3– non-estimable; P = 0.96). Results were similar after adjusting for patient characteristics in the Cox regression with hazard ratio (HR): 0.84; 95% CI: 0.29–2.43; P = 0.75). The median OS was 44.6 months (95% CI, 12.5– non-estimable) for patients with MTX AUC &amp;lt; 3648 μmol*l−1h and not estimable for patients with MTX-AUC &amp;gt; 3648 μmol*l−1h , HR of 0.43 (95% CI: 0.08–2.33; P = 0.33). Higher KPS prior to chemotherapy was associated with improved PFS/OS with HR: 0.95 (95% CI: 0.93–0.98; P = 0.0006) and HR: 0.91 (95% CI: 0.87–0.96; P = 0.0005) respectively. CONCLUSION Our patients PFS and OS is improved compared to historical control but our data suggests that there is no statistically significant association with MTX-AUC in PCNSL.

RBIO-07. HIGHER CSF IL-10 CORRELATE WITH BRAIN ATROPHY AFTER WHOLE BRAIN RADIATION THERAPY IN PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMA

Abstract Whole brain radiation therapy (WBRT) to primary central nervous system lymphoma (PCNSL) correlate with brain atrophy and leukoencephalopathy on serial computed tomography or MRI scans, negatively impacting cognitive function and quality of life. We retrospectively evaluated 53 patients with histologically proven PCNSL who underwent cerebrospinal fluid (CSF) examination including β2-MG, sIL2R, CXCL13, and IL-10 preoperatively. All patients were newly diagnosed and followed up every 3 months from the day they were discharged from the hospital. Follow up period is at least 1 year from last day of chemotherapy. Clinical data included patient demographics, radiological and characteristics; whole brain volume (mm2) calculated from BainLabTM automatically, Global Cortical Atrophy (GCA) for global brain atrophy, Medial Temporal Atrophy (MTA) for temporal atrophy, and Fazekas scale for white matter lesions. The unpaired t test and multivariable liner regression were used to examine the clinical, CSF and radiological characteristics of patients. The mean age at symptom onset was 65.2 years (47-85 years). Thirty three of 53 (62%) patients underwent WBRT with chemotherapy (WBRT group). In all patients, multivariable analysis revealed WBRT correlate with brain volume reduction (p=0.0005) and progression of temporal lobe atrophy (p=0.0056). In addition, Age correlated with increasing white matter lesions at 1 year after chemotherapy (p=0.0422). In WBRT group, multivariable analysis indicated that high CSF IL-10 level accelerated brain volume reduction (p=0.0122) and temporal lobe atrophy (p=0.0343) at 6 months after chemotherapy. However, there were no significant factor for influencing brain atrophy at 1 year. Higher IL-10 ( &amp;gt; 100mg/ml) level demonstrated higher brain atrophy rate (p=0.0366) and severe temporal atrophy at 1 year (p=0.0214). In elderly patients with high preoperative CSF IL-10 levels, cerebral atrophy and toxic leukoencephalopathy may progress in short period of time after WBRT. We should consider treatment strategy that avoid WBRT, such as R-MPV chemotherapy, for PCNSL patients.

NIMG-98. IDENTIFYING PATTERNS OF FAILURE AFTER INITIAL THERAPY IN PRIMARY CNS LYMPHOMA IN A LARGE PATIENT COHORT

Abstract INTRODUCTION Treatment of primary CNS lymphoma (PCNSL) has rapidly evolved, emphasizing improved efficacy while reducing neurotoxicity. PCNSL has historically been considered a multifocal disease and many patients relapse after first-line therapy. We evaluated relapse patterns in a large cohort of contemporarily treated patients. METHODS Consecutive PCNSL patients treated at MSKCC between 1983-2020 were analyzed. T1 post-contrast-enhancing disease on baseline MRI was characterized. Site of initial relapse was characterized as purely local (involving/adjacent to initial site) vs distant intraparenchymal, or other (e.g., both local and distant, systemic, ocular). Progression-free survival (PFS) was evaluated using Kaplan Meier methods. RESULTS Of 645 patients, 564 were eligible for analysis (diffuse large B-cell histology, sufficient data, ≥ 1 MRI response assessment). Median follow-up was 2.7 years (IQR 1.2-5.6). Median age was 63 years (range 19-90). Baseline disease was often supratentorial (420, 74%), multifocal (274, 49%), and bilateral (224, 40%). Fewer had leptomeningeal disease (94/430 CSF+, 22%; 117/559 radiographically positive, 21%). Most received methotrexate (MTX)-based induction (534, 96%), most commonly rituximab, MTX, procarbazine, vincristine (R-MVP; 257, 46%) or MVP (144, 26%). Overall, 286 (51%) patients relapsed with a median PFS of 2.1 years (95% CI 1.8-2.5). Of 275 characterizable relapses, 75 (27%) were exclusively local intraparenchymal, 91 (33%) were distant intraparenchymal, and 109 (40%) were other. Baseline unifocal disease often relapsed unifocally (66/118 baseline unifocal; 56%). Of 126 unifocal relapses, 45 (36%) were local. Of 202 patients with baseline supratentorial disease, 152 (75%) relapsed supratentorially. Unilateral relapses often remain ipsilateral (49% left- and 54% right-hemispheric lesions at baseline and relapse). CONCLUSIONS In a large PCNSL cohort, relapses often maintained baseline characteristics. For a disease historically considered multifocal, a substantial proportion of relapses were local. Future analyses will evaluate predictors of relapse, which can further efforts in informing personalization of treatment in the era of cellular therapies.

Proposed new prognostic model using the systemic immune-inflammation index for primary central nervous system lymphoma: A prospective-retrospective multicohort analysis

The systemic immune-inflammation index (SII) has been considered a novel prognostic biomarker in several types of lymphoma. Our aims were to determine the best statistical relationship between pretreatment SII and survival and to combination of SII and the Memorial Sloan Kettering Cancer Center model (MSKCC) to derive the best prognostic mode in primary central nervous system lymphoma (PCNSL). Pretreatment SII and clinical data in 174 newly diagnosed PCNSL patients were included from two retrospective discovery cohorts (n = 128) and one prospective validation cohort (n = 46). A generalized additive model, Kaplan-Meier curve, and Cox analysis were performed. The high risk versus low risk of SII-MSKCC for the PCNSL cutoff point (0-1 vs. 2-4) was determined by the minimum P-value approach. The SII showed a U-shaped relationship with the risk of overall survival (OS; P = 0.006). The patients with low SII or high SII had poorer OS and progression-free survival (PFS) than those with median SII. For PFS and OS, SII-MSKCC was a better predictor than MSKCC alone. The area under the receiver operating characteristic curve of the SII-MSKCC score was 0.84 for OS and 0.78 for PFS in the discovery cohorts. The predictive value of the SII-MSKCC score (OS, 0.88; PFS, 0.95) was verified through the validation cohort. Multivariable Cox analysis and Kaplan-Meier curve showed excellent performance for SII-MSKCC, with significant separation of two groups and better performance than MSKCC alone. We propose a new prognostic model using SII, age, and Karnofsky score that outperforms MSKCC alone and enables individualized estimates of patient outcome.