Central Nervous System Lymphoma Research Articles

PD-1 Blockade Combined with R-CHOP in Patients with Newly Diagnosed EBV-Positive Diffuse Large B-Cell Lymphoma: A Retrospective Analysis

Background Epstein-Barr virus (EBV) -positive diffuse large B cell lymphoma (EBV+ DLBCL) is a relatively rare aggressive B-cell lymphoma. Most patients present with advanced disease, high incidence of extranodal involvement of 30% to 80% (Keane, Eur J Haematol, 2019), as well as poor prognosis when treated with immunochemotherapy. However, no consensus on standard treatment has been established by now. It was found that the expression of programmed death ligand-1 (PD-L1) was increased in EBV+ DLBCL (Kim, Cancer Res Treat, 2019). In addition, chronic EBV infection results in T-cell exhaustion that can be reversed by PD-1 blockade. Compared with PD-L1-positive EBV-negative DLBCL cell lines, the application of PD-1 blockade in PD-L1-positive EBV+ DLBCL cell lines can significantly restore T cell proliferation and activity(Quan, PLoS One, 2015), suggesting that targeting the PD-L1/PD-1 pathway represents a potential therapy for EBV+ DLBCL. Therefore, we retrospectively analyzed the data of nineteen patients with EBV+ DLBCL who were treated with PD-1 blockade combined with RCHOP in our center, hoping to provide reference for subsequent research. Methods Eligible pts had treatment-naive histologically confirmed diagnosis of EBV+ DLBCL. Additional eligibility criteria included at least one measurable lesion, acceptable haptic and hematological function. Pts with primary CNS lymphoma, primary mediastinal large B-cell lymphoma, secondary CNS involvement were excluded. Additional exclusion criteria included history of immune system disease, uncontrolled infection. Once deemed eligible, pts will receive six cycles of RCHOP combined with PD-1 blockade(21 days per cycle) as induction therapy and subsequently maintenance with PD-1 blockade for 1 year(21 days per cycle). End of treatment(EOT) responses were assessed by PET-CT according to the Lugano Classification 2014. The primary objective was to assess the overall response rate(ORR) at EOT. Results Between May 1, 2019, and Sep 1, 2022, 19 pts were enrolled. Pts' baseline demographics, clinical and pathological characteristics are shown in Table 1. The median age was 64 years old without significant gender difference. The majority of pts were intermediate- to high-risk by IPI. EBV DNA can be detected in blood serum at diagnosis in more than half of all patients. No patient was diagnosed with double expressor lymphoma among 18 specimens that were detected c-Myc and BCL-2 with immumohistochemical staining. EBV-encoded RNA (EBER) was positive(>80% of the tumor cells) in all specimens. PD-L1 positivity(>10% of the tumor cells) or CD30 positivity(>5% of the tumor cells) was also quite common. Besides, no double hit lymphoma was confirmed in patient with Fluorescence situ hybridization test(n=13). Treatment course and efficacy evaluation of all pts are summarized in Figure 1. All patients enrolled in this study had completed 6 cycles of induction therapy. Totally, the ORR at EOT was 94.7%, and all achieved CMR. The ORR of patients with PD-L1 positivity(n=10) was numerically higher than that of patients with negative PD-L1 expression (n=5) (100% vs 80%). EBV DNA detected in blood serum of thirteen patients have decreased to undetectable level after induction therapy. The immune-related adverse events (irAEs) were emphatically analyzed. One patient had recurrent fever after every dose of PD-1 blockade without obvious evidence of infection. Another patient developed grade 3 diarrhea since the second cycle of PD-1 blockade maintenance. Colonoscopy showed mucosal swelling and multiple superficial ulcers in the whole colon, which indicated immune colonitis. Maintenance therapy was therefore discontinued. No irAE was observed in the rest of patients. With a median follow-up time of 13.1m (7.2-38.5m), the median PFS and OS were not reached. Both of 1 year OS and PFS was 89.5%. Overall, 2 pts experienced disease progression (1 at EOT, 1 at 2 months after ASCT), 2 pts died (1 due to progressive disease, 1 due to COVID-19 infection ). Conclusions PD-1 blockade combined with R-CHOP as induction therapy in patients with newly diagnosed EBV+ DLBCL has demonstrated satisfactory response and limited irAEs. Longer follow-up is still warranted to confirm the long-term benefit, especially for patients with maintenance of PD-1 blockade. Still, we believe this therapeutic strategy can be regarded as a successful attempt at improving prognosis for pts with EBV+ DLBCL.

Ratio of Circulating CD8 + T Lymphocytes to M-MDSCs (CD8MMR): A Novel Prognostic Predictor for Treatment-Naïve DLBCL Patients

Introduction: CD8 + T lymphocytes are crucial in contemporary cell-and-immunotherapies as they can be functionally enhanced or manipulated. Monocytic myeloid-derived suppressor cells (M-MDSCs) are known for their intense immunosuppressive ability, and higher percentages of circulating M-MDSCs among peripheral-blood monocytes or white cells are associated with a worse prognosis. Recently, a low lymphocyte-to-monocyte ratio (LMR) has been linked to a poor prognosis in lymphoma patients. Consequently, we hypothesized that the ratio of circulating CD8 + T lymphocytes to M-MDSCs (CD8MMR) could be a novel and more precise predictor for the clinical outcomes of DLBCL patients before initiating treatment. Methods: This prospective, observational study enrolled 136 adults with treatment-naïve DLBCL from May 2019 to March 2023 in a tertiary medical center in Taiwan. Patients with primary CNS lymphoma or primary mediastinal B-cell lymphoma were excluded. Fresh peripheral blood samples were obtained to calculate the absolute counts of CD8 + T lymphocytes and M-MDSCs, defined as alive singlets with CD45 + CD3 + CD8 + and CD45 + CD15 - CD14 + CD11b + CD33 + HLA-DR low/- by flow cytometry, respectively. ROC analysis and AUC determined the cut-off values for LMR and CD8MMR. Results: For 136 treatment-naïve DLBCL patients, the median age was 70, with 61.8% being male. Among them, 37.5% were in stage IV, and 27.9% were classified as the germinal-center B-cell (GCB) subtype by IHC staining according to the Hans algorithm. Additionally, 43.4% were diagnosed with double expressor lymphoma (DEL). The IPI risk score distribution was as follows: 7.4%, 18.4%, 17.6%, 24.3%, 19.9%, and 12.5% were in scores 0, 1, 2, 3, 4, and 5, respectively. Of note, the median level of LMR was 2.17, the median level of absolute counts of circulating CD8 + T lymphocytes was 385/µL, the median level of absolute counts of circulating M-MDSCs was 102/µL, and the median level of CD8MMR was 3.56. DLBCL patients with high-risk IPI had a significantly lower CD8MMR than patients with intermediate or low-risk IPI (1.34 vs. 4.51 vs. 7.82, PH vs. L = 0.001, PH vs. I = 0.060, PI vs. L = 0.082). DLBCL patients with the non-GCB subtype (2.75 vs. 5.63, P = 0.031) also demonstrated a significantly lower CD8MMR. Additionally, there were trends of lower CD8MMR in elderly patients > 70 (2.74 vs. 3.91, P = 0.209) and patients with DEL (3.33 vs. 4.65, P = 0.101). After a median follow-up of 22.6 months for the 136 DLBCL patients, LMR was at first tested, and patients with LMR < 1.19 had significantly worse PFS (13.8 months vs. non-reach, Log Rank P = 0.004) and OS (non-reach vs. non-reach, Log Rank P = 0.019) than those with LMR ≥ 1.19. Next, we examined the CD8MMR, and patients with CD8MMR < 4.40 experienced significantly worse PFS (21.3 months vs. non-reach, Log Rank P < 0.001) and OS (non-reach vs. non-reach, Log Rank P < 0.001) compared to those with CD8MMR ≥ 4.40 [Figure]. We subsequently conducted a multivariate Cox regression analysis to validate whether CD8MMR < 4.40 could serve as an independent predictor of poor prognosis [Table]. The results showed that “CD8MMR < 4.40” was confirmed as an independent prognostic factor for both PFS (HR = 2.747; 95% CI = 1.275 to 5.918; P = 0.010) and OS (HR = 3.669; 95% CI = 1.462 to 9.211; P = 0.006) after adjusting for confounding factors, including age, sex, IPI risk scores, bulky mass > 10 cm, non-GCB type, DEL, and LMR < 1.19. In this study cohort, 106 (77.9%) patients received R-CHOP-like regimens as induction therapies, 25 (18.4%) patients received an R-EPOCH regimen, two (1.5%) patients received an R-HyperCVAD regimen, and three (2.2%) patients died before completing the first cycle of chemoimmunotherapy. Among the 106 DLBCL patients receiving R-CHOP-like regimens, 57 patients showed CD8MMR < 4.40 and reported a significantly lower rate of complete remission (73.7% vs. 95.9%, P = 0.006) at the end of induction therapy compared to the 49 patients with CD8MMR ≥ 4.40. Furthermore, patients with CD8MMR < 4.40 had significantly worse PFS (17.4 months vs. non-reach, P < 0.001) and OS (non-reach vs. non-reach, P < 0.001) compared to those with CD8MMR ≥ 4.40. Conclusion: A low ratio of circulating CD8 + T lymphocytes to M-MDSCs (CD8MMR) serves as a poor prognostic factor for both PFS and OS in treatment-naïve DLBCL patients. This finding warrants further investigation and highlights the possibility of risk-adapted strategies when treating DLBCL patients.

Outcomes in Routine Clinical Practice with Methotrexate-Temozolomide-Rituximab Induction and Modified Etoposide-Cytarabine Consolidation in Newly Diagnosed Primary CNS Lymphoma

Background: Recent studies have reported improved outcomes for patients with Primary CNS lymphoma (PCNSL) with addition of agents in induction (for e.g. cytarabine, thiotepa and rituximab in IELSG studies), intense consolidation (Autologous stem cell transplant (ASCT) as in IELSG 43) and intense non-myeloablative chemotherapy with etoposide/cytarabine (EA) as in CALGB 50202). Delivery of such an intense therapy is often difficult in clinical practice due to advanced age, comorbidities, poor performance status and resource constraints. We started using induction with methotrexate, temozolomide and rituximab (MTR) as per CALGB 50202 study however the intense non-myeloablative EA consolidation was not feasible. We used a strategy of reduced dose EA consolidation for 2 cycles with etoposide at 100 mg/m 2 over 2 hours and cytarabine 2 gm/m 2 twice daily for 2 or 3 days based on clinical judgement of the treating physician. Here we report outcomes with this approach in newly diagnosed PCNSL patients treated at our centre. Method: We did a retrospective analysis of patients with newly diagnosed PCNSL treated with MTR induction followed by modified EA consolidation. Kaplan-Meier was used to estimate progression free (PFS) and overall survival (OS). Variables influencing the outcomes with P less than 0.05 were considered significant. Results: Between January 2015 to December 2022, 72 patients were treated with above protocol with a median age of 46.5 years (range, 17 to 68 years) and 50 (69.4%) were males. Median ECOG performance score at presentation was 1 with 16 (22%) patients having ECOG performance score of 3 or more. IELSG scores were high and intermediate risk in 26 (36.1%) and 27 (37.5%) respectively while only 7 (9.7%) were in the low risk (data was not available for remaining 12 (17%) patients). MSKCC scores were available for all patients with 43 (59%) patients in class 1, 14 (19%) patients in class 2 and 15 (20%) patients in class 3. MTR induction with a dose of 8 gm/m2 could be delivered for all 4 cycles in 64 (88%) patients. Dose reduction was required in 14 (19.4%) patients; reasons were renal dysfunction in 8 (11%), infections in 3 (4%), liver dysfunction in 2 (3%). Nine patients (12.5%) had disease progression during induction. Total of 54 patients received consolidation with systemic therapy. Dose reduced EA consolidation was delivered in 46 (63%) patients while 8 patients received single agent high dose cytarabine consolidation and only 3 patients underwent ASCT. Seven patients received WBRT consolidation. EA consolidation was given for 2 days in 30 (65%) patients while 16 (35%) patients received 3 days of EA consolidation. Twenty six patients received maintenance lenalidomide. With a median follow up of 39.2 months (range, 2.1 to 91), median PFS is 46.9 months and median overall OS has not reached. Three years PFS & OS for all patients is 59.5% and 78% respectively ( Fig 1A &B). Median PFS and OS of patients receiving EA consolidation has not been reached with a 3-year PFS and OS of 77% and 79% respectively. MSKCC score was predictive of OS with 3 year OS in class 1, 2 and 3 of 89.5%, 68% and 58% respectively. Consolidation with split dose EA was associated with better OS and PFS as compared to single agent cytarabine alone. None of the 3 patients receiving ASCT have relapsed. Patients receiving full dose methotrexate had better OS compared to patients requiring dose reduction. Two versus 3 day EA consolidation had no impact on OS. MTR induction was well tolerated with grade 3 or more toxicity as follows: renal dysfunction in 8 (11%) patients, transaminitis in 4 and febrile neutropenia in 4 patients with no treatment related deaths. EA consolidation resulted in 18 episodes of febrile neutropenia with two deaths. Grade 3 or more hematologic toxicities were common with grade 3 or more anaemia, neutropenia and thrombocytopenia in 15 (32%), 40 (86%), 33 (71%) patients respectively. There were two deaths in the consolidation phase, one due to intracranial bleeding and another due to febrile neutropenia. Conclusion: MTR induction with modified EA consolidation is feasible and results in optimal outcomes in real world setting. Higher cumulative methotrexate dose and use of EA consolidation were associated with better OS. These outcomes compare favourably to CALGB 50202 study and represent a feasible option in resource limited setting.

Pacritinib Blocks Key Pro-Survival Signaling Related to Mutated MYD88, Produces High Levels of Apoptosis and Overcomes Mutated BTK Cys481 Related BTK-Inhibitor Resistance

Background: Somatic mutations in MYD88 are prevalent in many B-cell malignancies, including Waldenström Macroglobulinemia (WM; 95-97%), primary CNS lymphoma (70-80%), ABC DLBCL (40%), marginal zone lymphoma (5-10%) and CLL (5-15%). Mutated MYD88 drives oncogenic pro-survival signaling through multiple signaling cascades that include HCK-directed BTK, ERK and SYK, as well as IRAK1/IRAK4 activation. HCK is an SRC family member that mutated MYD88 transcriptionally upregulates, and its activation is triggered by IL-6/IL-6R/gp130/JAK2 signaling. BTK inhibitors are active in MYD88 mutated B-cell malignancies, but fail to produce complete responses, and show varying durations of response that are disease dependent and impacted by depth of response. Acquired resistance to BTK inhibitors is commonly related to a BTK Cys481 mutation. Pacritinib is a kinase inhibitor, FDA-approved for myelofibrosis, that is well tolerated and targets pro-signaling cascades that are relevant to mutated MYD88 signaling, including IRAK1, JAK2, and SRC, a homologue of HCK ( Fig. 1). Pacritinib may therefore represent a more effective option in blocking mutated MYD88 pro-survival signaling versus BTK-inhibitors. Methods: We performed comparative studies to evaluate the activity of pacritinib and the covalent BTK-inhibitors ibrutinib and zanubrutinib on mutated MYD88 relevant pro-survival signaling, as well as proliferation and survival in MYD88 mutated cell lines and primary MYD88-mutated WM cells. Further to these studies, we assessed the activity of pacritinib in well-characterized mutant (BTK Cys481Ser) expressing covalent BTK-inhibitor resistant WM and ABC DLBCL lymphoma cell models. Results: Pacritinib produced higher levels of apoptosis in MYD88-mutated WM (BCWM.1) and ABC DLBCL (TMD-8), and primary (CD19 +) MYD88-mutated WM cells relative to the BTK inhibitors ibrutinib or zanubrutinib.The apoptotic activity of pacritinib showed dose dependence with high levels of apoptosis at 0.5 µM, which is well within its pharmacologically achievable levels. Importantly, pacritinib, in addition to its known effects on JAK2 and IRAK1 activation, also showed robust inhibition of p-HCK (Y411) and its downstream signaling partner p-BTK (Y223) in MYD88 mutated BCWM.1 and TMD-8 cells. By combination index and normalized isobologram analyses, pacritinib showed synergistic interactions with covalent BTK inhibitors, and more so with the BCL-2 inhibitor venetoclax in MYD88 mutated cell lines and primary WM cells. Lastly, pacritinib alone and combined with venetoclax induced high levels of apoptosis in BTK Cys481Ser expressing covalent BTK-inhibitor resistant MYD88 mutated WM and ABC DLBCL lymphoma cells. Conclusions: Pacritinib more broadly extinguishes mutated MYD88 pro-survival signaling cascades ( Fig 1.) and demonstrates high levels of apoptotic activityin mutated MYD88 WM and ABC DLBCL cells versus selective covalent BTK-inhibitors. Pacritinib also synergizes with covalent BTK- and BCL2 inhibitors and can overcome covalent BTK-inhibitor resistance related to mutated BTK Cys481. Our studies provide a framework for investigating pacritinib in MYD88 mutated lymphomas. A clinical trial of pacritinib in relapsed/refractory WM is being initiated.

Pregnancy in Patents with CLL Systematic Review

Introduction: Chronic Lymphocytic Leukemia (CLL) is a hematologic malignancy characterized by the clonal expansion of non-functional, mature-appearing lymphocytes in the bone marrow, peripheral blood, and lymphoid tissues. While cases of CLL during pregnancy are rare,it is associated with many complications. It was reported that women with CLL are more susceptible to infections due to a weakened immune system; possibly leading to more complications. There is also increased risk of thrombocytopenia, which can increase the risk of bleeding during pregnancy and childbirth. This review aimed at identifying literature available on the complications in CLL and pregnancy as well as the data available on the potential therapeutic strategies. Methods: A scoping review of case reports that discuss pregnant patients who were diagnosed with CLL were isolated. The effects of the disease on pregnancy outcomes regarding both mother and fetus were identified. Animal studies, reviews or non-original articles, and non-English articles were excluded from our study. FDA labels of medications in CLL were reviewed for data on pregnancy and animal outcomes. Information on those medications in pregnant patients were also identified where available. Results: The search strategy across four databases yielded 448 articles. After eligibility assessment, 14 articles were included in the review. Cases were subdivided according to timing of pregnancy relative to CLL diagnosis (diagnosed before pregnancy or during pregnancy at early or late gestational periods). The pre-pregnancy reports were further subclassified based on the presence or absence of infection during pregnancy. None of the cases reported required immediate initiation of CLL therapy and only one case reported mortality post-delivery. This occurred in a patient with Richter transformation and no prior CLL treatments. There were no reported fetal malformations or severe adverse outcomes related to the infants in any of the reported pregnancies ( Figure 2). The included studies provided insights into various aspects of CLL during pregnancy, including patient demographics, diagnosis timing and methods, acquired infections, changes in white blood cell count, treatment approaches, pregnancy outcomes, and complications for both mother and fetus. From the marketed pharmacological alternatives for CLL, most were not studied in pregnant humans with CLL ( Figure 1). However, venetoclax and rituximab have some data in pregnant patients with non-CLL indications. A case reported a pregnant refractory AML patient who received venetoclax with high dose cytarabine and mitoxantrone at 24 weeks of gestation. Bone marrow at 27 weeks showed complete remission and labor was induced at 28 weeks + 5 days after corticosteroid-induced lung maturation. The infant had hyperbilirubinemia, transient B-cell depletion and required ventilation. The baby recovered from all complications, although possible long-term effects are still unclear. The mother underwent allogeneic hematopoietic stem cell transplant. In a 30-year-old female (pregnant at 28 weeks) with primary CNS lymphoma, weekly rituximab was given for 4 weeks with dexamethasone. After delivery through C-section at 31 weeks, the patient started definitive treatment with chemotherapy and autologous transplant. The infant required brief mechanical ventilation and had transient B-cell depletion at delivery until 4 months post-delivery. The baby required a course of post-exposure acyclovir despite not developing an infection. Both mother and baby survived with good outcomes at last follow-up (4 years post-delivery) Conclusion: Despite the rarity of CLL occurrence during pregnancy, there is evident need of further studies and management guidelines in this population. This review provides insights into the possible pregnancy-related concerns in women with CLL at different disease stages. While watchful waiting is generally recommended due to CLL's slow progression, individual evaluation is crucial. If treatment is necessary, delaying therapy until the second or third trimesters may help mitigate the risk of fetal malformations. The increased susceptibility to infections resulting from the combined immunosuppressive effects of CLL and pregnancy should be carefully considered

Novel Protacs Demonstrate Dual Kinase Inhibition and Degradation of HCK and BTK, and Are Highly Active in MYD88 Mutated WM and ABC DLBCL Cells

Background: Activating mutations in MYD88 are prevalent in many B-cell malignancies, including Waldenström Macroglobulinemia (95-97%), primary CNS lymphoma (70-80%), ABC DLBCL (40%), marginal zone lymphoma (5-10%), and CLL (5-15%). Mutated MYD88 transcriptionally upregulates the SRC family member HCK, which in turn serves as a master signal for triggering multiple pro-survival cascades in mutated MYD88 lymphoma cells including BTK/NFKB, SYK, and ERK (Blood 127:3237-52; Blood Adv 4:141-153; Blood Adv 6:3332-38). In previous work, we developed and characterized a novel HCK kinase inhibitor, KIN-8194 (Blood 138:1966-79). KIN-8194 blocked both HCK and BTK and was active both in vitro and in vivo in MYD88 mutated xenograft lymphoma models, including BTK Cys481Ser ibrutinib resistant models. Proteolysis targeting chimeras (PROTACs) represent a novel approach for blocking kinase based signaling and may provide an advantage over kinase inhibitors with greater selectivity and sustained target inhibition. We therefore initiated a medicinal chemistry campaign to develop highly potent, selective, and bio-available HCK/BTK targeting PROTACS using KIN-8194 scaffold for the treatment of MYD88 driven lymphomas. Methods: We developed and characterized a large series of PROTACs using KIN-8194 as a scaffold. We rationally designed linkers to facilitate E3 ubiquitin ligase binding and improve physical properties leading to degraders with ideal oral pharmacokinetic properties and bioavailability. We characterized their kinome profiling by performing a KINOMEscan assay against a panel of 468 kinases at 1 uM ( Fig. 1). Subsequently, we conducted rigorous biological efficacy screenings using the ATP-based Cell Titer-Glo Luminescent Cell Viability Assay to identify the most potent compounds. Compounds with IC 50 scores lower than KIN-8194 were selected for further validation through flow cytometry based quantitative assays that verified apoptotic and cytotoxic effects on WM and MYD88-mutated lymphoma cell lines, as well as primary human peripheral blood mononuclear cells (PBMCs), utilizing Annexin V and Propidium iodide (PI) staining. Results: We identified and characterized several novel PROTACs from the KIN-8194 scaffold that exhibited potent dual inhibition of HCK and BTK kinase activity at 1 nM, as well as marked degradation of HCK and BTK by western blot analysis at dose levels as low as 100 nM in MYD88 mutated WM and ABC DLBCL cell lines. KINOMEscan profiling showed greater selectivity for novel PROTACs as exemplified in Fig. 1. Enhanced cell killing due to degradation of HCK and BTK versus inhibition alone was confirmed using respective PROTAC analogues with modified IMID warheads that do not bind cereblon. We observed suppression of downstream pro-survival NFKB and ERK signaling in response to the dual HCK/BTK PROTACs. Moreover, several HCK/BTK PROTACs (DFCI-004, -005, -006) demonstrated remarkable low IC 50 values (1-100 nM) in proliferation assays of MYD88 mutated BCWM.1 WM and TMD-8 ABC DLBCL cells. Importantly, the dual HCK/BTK PROTACs elicited higher levels of apoptosis in BCWM.1 WM and TMD-8 ABC DLBCL cells in comparison to the native KIN-8194 kinase inhibitor and showed sparing of healthy donor B- and T-cells akin to KIN-8194. Finally, murine PK studies showed that the HCK/BTK PROTACs DFCI-005 and -006 were highly bioavailable with F=40-42%, and C Max of 700-2700 nM at single oral dose ranges of 10-60 mg/kg. Conclusions: In these studies, we demonstrated the development and characterization of novel, dual HCK/BTK PROTACs that demonstrate potent and selective kinase inhibition and protein degradation of HCK and BTK. Importantly, the novel PROTACs showed enhanced apoptosis of MYD88 mutated WM and ABC DLBCL cells over the native kinase inhibitor KIN-8194 and sparing of healthy donor B- and T-cells. Lastly, novel HCK/BTK PROTACs exhibited high levels of bioavailability. Our studies therefore provide a framework for the advancement of dual HCK/BTK PROTACs for the treatment of MYD88 mutated lymphomas.

Skeletal Muscle Index, As a Measure of Muscle Mass, Is a Significant Prognostic Factor for Newly Diagnosed Diffuse Large B-Cell Primary CNS Lymphoma Patients

Background: Primary cerebral lymphoma (PCNSL) is a rare subtype of diffuse large B-cell lymphoma (DLBCL) with a particularly poor outcome compared to systemic DLBCL. Several prognostic scores have been developed for PCNSL. These include the International Extranodal Lymphoma Study Group (IELSG) score with five prognostic factors (patient age, serum lactate dehydrogenase [LDH] level, Eastern Cooperative Oncology Group performance status [PS], deep brain involvement and cerebrospinal fluid [CSF] protein level), and the Memorial Sloan-Kettering Cancer Center (MSKCC) score, which is based on age and the Karnofsky Performance Score (KPS). However, the reproducibility of these two scoring systems is low, and the IESLG score requires CSF protein and LDH levels evaluation, which are not often available. None of these scores incorporate data on nutritional status, in particular albumin, which has been shown to be an important prognostic factor in systemic DLBCL. In addition, a recent study demonstrated that the muscle density and mass determined by imaging segmentation, were strong prognostic factors for newly diagnosed systemic DLBCL patients (Jullien et al. Cancers 2021). Our aim was to determine whether these imaging data were also predictive factors for outcome in newly diagnosed diffuse large B-cell PCNSL patients. Methods: For each patient included in the study, muscle mass and density were estimated using skeletal muscle index (SMI) and mean skeletal muscle radiation attenuation (SMRA), respectively. SMI and SMRA were computed at L3 level using the whole-body scan (WBS) performed at the diagnosis of PCNSL, by the mean of an automated segmenting algorithm. Muscle characteristics were then classified as normal or low using already validated cut-off according to patients' age and body mass index (Westenberg et al. Sci Rep 2023). Patients' outcomes were then compared based on their muscle quality, albumin level at diagnosis and other clinical variables commonly included in PCNSL prognostic scores. Results: Between 2015 and 2022, 98 consecutive diffuse large B-cell PCNSL patients were newly diagnosed at Hematology Department of Hospital Lyon Sud, France. Among them, 77 had WBS at diagnosis with available data for this study. The median age was 69 years (range 24-87) and 22 patients (29%) presented an altered ECOG PS (PS 3-4 score). All patients were treated with first-line high-dose methotrexate-based chemotherapy in combination with rituximab. SMI was normal in 64 patients (83%) and 17 patients (17%) had low SMI. Patients with low SMI had more frequently an altered PS (p=0.07) and had lower albumin level (mean 36.7 g/L vs 32.0 g/L, p=0.007). SMRA was normal in 30 patients (39%) and 47 patients (61%) had low SMRA. Patients with low SMRA were older (60 vs 70 years old, p=0.001). In univariate analysis, patients with low SMI had worse outcome with significantly shorter overall survival (p=0.002, median OS, 21.4 months vs not reached) and a trend towards shorter event-free survival (p=0.055, median EFS, 11.9 months vs 42.3 months, Figure 1). No significant prognostic difference was seen for SMRA for EFS or OS. The multivariate analysis showed that SMI (Hazard ratio [HR]=3.33, 95% confidence interval [95%CI]= 1.21-9.20, p=0.02) and age (HR =1.86, 95%CI =1.15-3.0, p=0.012) were strongly associated with OS but not tumor localization (HR =1.46, 95%CI =0.60-3.55, p=0.4), PS (HR = 1.54, 95%CI =0.65-3.65, p=0.32) and albumin level (HR =1.05, 95%CI =0.47-2.32, p=0.91). Age was significantly associated with EFS (HR=1.4, p = 0.04) with a more limited association of SMI with EFS (HR=2.03, p=0.095). In exploratory subgroup analyses, we showed that SMI still influenced OS in patients with PS 4 (10 months vs not reached, p= 0.002), suggesting that SMI may be a more appropriate prognostic factor than PS, especially for patients with motor deficit for whom PS is difficult to estimate. Conclusions: This retrospective analysis of newly diagnosed PCNSL patients showed a significant association between decreased muscle mass, measured by SMI and overall survival, after controlling for other prognostic variables. These findings warrant confirmative analyses to explore the relationship between muscle mass/density and diffuse large B-cell PCNSL patient's outcome and integrate SMI in PCNSL prognostic scores.

A Retrospective Study on Outcomes of Secondary CNS Lymphoma: Pattern of Relapse, Prognostic Factors, and Role of Consolidation Therapy

Introduction Secondary CNS lymphoma (SCNSL) remains a treatment challenge in patients (pts) with aggressive lymphoma. Outcome of SCNSL is poor. Pts are often treated with high dose Methotrexate (HD-MTX) based regimens followed by autologous stem cell transplant (auto SCT). However, the benefit of consolidation therapy is not well established. There is limited data on the treatments and outcomes of SCNSL. In this single institution study, we aim to analyze the role of consolidation therapy and potential prognostic factors of outcomes in SCNSL. Method All pts with a diagnosis SCNSL who presented to Moffitt Cancer Center, FL, USA between 2017 and 2022 were included. The hazard ratios (HRs) were evaluated in the univariate and multivariate analysis using the cox proportional hazard mode. All analyses were done using SAS 9.4. Results A total of 60 pts with SCNSL were identified. The median age was 63 years (range 26-83 years); 27 (45%) were female; 13 (21.7%) had Eastern cooperative oncology group performance status (ECOG) ≥2. Entire cohort was divided in 3 subgroups: pts with concurrent CNS involvement at the time of initial diagnosis with systemic lymphoma (Sys-CNS) [22 (36.7%)]; pts with isolated CNS relapse (R-SCNS) [30 (50.0%)]; and pts with simultaneous CNS and systemic relapse (R-Sys-CNS) [8 (13.3%)]. 31 (51.7%) pts had brain parenchymal involvement, 24 (40%) had leptomeningeal disease, 4 (6.7%) had both leptomeningeal and parenchymal involvement, and 1 (1.7%) had ocular disease. 58(96.6%) pts had diffuse large B cell lymphoma (DLBCL) histology; 9 (15%) had DLBCL with MYC and BCL2 rearrangement; 10 (16.7%) had DLBCL MYC and BCL2 expression. For induction therapy of SCNSL, 53 (88.3%) of pts received HD MTX-based chemotherapy; 2 (3.3%) received Bruton tyrosine kinase inhibitor (BTKi), and 5 (8.3%) with meningeal disease alone received IT chemotherapy and/or rituximab(R). Sys-CNS pts also received R-CHOP or DA-R-EPOCH while R-Sys-CNS pts received R-Polatuzumab or Polatuzumab-R-Bendamustine. 20 (33.3%) received consolidation either by WBRT [13 (21.7%)] or auto SCT [4 (6.7%)]; 3 (5.0%) proceeded with chimeric antigen receptor (CAR-T) therapy. The overall response rate (ORR) for entire cohort was 55.2% (34.5% complete response CR and 20.7% partial response PR). However, improved ORR and CR were observed with 14(73.68%) and 9 (47.37%) respectively in pts who received consolidation. ORR and CR for pts with Sys-CNS, R-SCNS, R-Sys-CNS were 13 (61.9%)/ 10 (47.6%), 14 (48.3%)/9 (31%) and 2 (25%)/ 2 (25%), respectively. After a median follow up of 33.6 months, median OS was 8.3 months with a 2-year survival probability of 33.8% (95% CI: 21.7-46.3%); the PFS was 6.5 months with a 2-year PFS probability of 32.9% (95% CI: 20.7-45.6%). Consolidation therapy with either auto SCT or WBRT had significant survival benefit. In this subgroup, median OS is not reached (NR) and the 2-year OS probability was 59.6% (95% CI: 32.9-78.7%); median PFS was 25.6 months and 2-year PFS probability was 53.3% (95% CI: 27.5-73.6%). After the first-line therapy for CNS disease, 21(35%) pts experienced relapsed. However, relapse rate in consolidation group [7 (36.8%)] was almost similar to those who did not receive consolidation [14 (34.2%)] (table 1). 39 (65%) pts died; 29 (48.33%) from disease progression, 3 (5%) from therapy related side effect and 7(11.7%) from other causes. In the univariate analysis, ECOG PS ≥2 [HR 3.60 (CI:1.80-7.20), p<0.001], lack of consolidation therapy [2.45 (CI:1.12-5.36), p=0.024], <3 cycles of HD-MTX containing regimen [2.85 (CI: 1.47-5.520), p=0.002] and double hit lymphoma [2.27 (CI: 1.02-5.06), p=0.045] were associated with worse OS. In the multivariate analysis, R-SYS-CNS, <3 cycles of HD-MTX, ECOG ≥2 and lack of consolidation remained significant. Lack of consolidation and receiving <3 cycles of HD-MTX were associated with inferior PFS in both univariate and multivariate analysis (figure 1). Conclusion Outcomes of aggressive B cell lymphoma with CNS involvement remain poor. The median OS was 8.3 months in our cohort. After adjusting for confounding factors, receiving >3 cycles of HD-MTX based regimen and consolidation with either WBRT or auto SCT were associated with improved outcomes. Pts with simultaneous CNS and systemic relapse had worse OS. Prospective studies are needed to evaluate optimal treatment for SCNSL.

Radiotherapy As an Effective Bridge for Relapsed/Refractory Secondary CNS Lymphoma

Introduction: Secondary CNS lymphoma (SCNSL) is observed in 2-5% of patients with diffuse large B cell lymphoma (DLBCL). Progression of SCNSL after first line CNS-directed systemic therapy is particularly challenging to treat, without a clear standard of care. Brain radiotherapy (RT) is used for progressive SCNSL in either the chemo-refractory or palliative setting. Historically, the RT field included the whole brain due to concerns about diffuse intracranial involvement. However, treatment fields limited to just involved site(s) (partial brain RT) may provide a favorable balance of disease control and reduced treatment toxicity, particularly in an era of improved CNS-directed systemic therapies. We hypothesized that RT would confer a high rate of intracranial response among patients with chemo-refractory SCNSL. Methods: We identified DLBCL patients with SCNSL who received brain RT at our institution for radiographic or clinical progression after at least 1 line of SCNSL-directed therapy. SCNSL-directed therapy was defined as systemic therapy for active SCNSL (as opposed to prophylaxis). Overall survival (OS) was determined from RT start to death from any cause using the Kaplan-Meier method. OS comparing subsequent therapy was landmarked 2 months post RT to minimize immortal time bias. RT response was evaluated with contrast MRI or CT using International Primary CNS Lymphoma Collaborative Group (IPCG) or Response Assessment in Neuro-oncology (RANO) radiographic criteria for parenchymal or leptomeningeal disease (LMD), respectively. LMD was assessed by cytology and/or imaging. Results: Between 1999-2023, 55 patients received brain RT for progressive SCNSL with median follow up of 3.2 months. At the time of RT, median age was 64 (interquartile range (IQR) 49 - 71), median Karnofsky Performance Status was 70 (IQR, 60 - 80), and 85% had neurologic symptoms. Patients had received a median of 2 lines of SCNSL-directed therapy prior to RT (IQR, 1 - 3), 91% received a methotrexate-based regimen with median interval of 21 days (IQR, 10 - 67) between methotrexate and RT. Median RT dose was 30 Gy in 10 fractions delivered to whole brain (n = 44), partial brain (n = 9), or craniospinal axis (n = 2). 38 patients were evaluable for response; the remainder were lost to follow up/hospice (n = 8), lacked suitable imaging (n = 4), died with progressive neurologic symptoms (n = 4) or other cause (n = 1). The overall response rate was 79%, including a 24% complete response rate. Median time to best response was 60 days (IQR, 30 - 145). 32/55 patients (58%) were successfully bridged to subsequent systemic therapy (n = 22), hematopoietic stem cell transplantation (autologous n = 4, allogeneic n = 1), or CAR T (n = 5), after a median of 34 days from RT (IQR, 20 - 57). Median OS for the entire cohort was 3.5 months, and was improved for those who were bridged to subsequent therapy (no subsequent therapy 0.7 months, subsequent systemic therapy 4.0 months, subsequent cell therapy 8.9 months, p = 0.006). Among patients who received partial brain RT, 7/7 evaluable patients had at least a partial response and 7/9 patients were successfully bridged to subsequent therapy. Conclusion: Patients referred to RT for progressive SCNSL represent a high-risk cohort characterized by rapidly progressive, symptomatic, treatment-resistant disease. RT confers a high response rate in this chemo-resistant population, and can facilitate bridging to subsequent therapy. Preliminary data suggest that partial brain radiotherapy may be an effective bridging strategy among select patients, however a larger sample size will be required to determine this.

Co-Expression of C-MYC/BCL2 Is Associated with Inferior Survival Outcomes in Relapsed/Refractory Diffuse Large B-Cell Lymphoma after Autologous Stem Cell Transplantation - a Nationwide Retrospective Analysis in Singapore

Introduction Co-expression of C-MYC and BCL2 in diffuse large b-cell lymphomas (DLBCL), also termed double-expressor lymphomas (DEL), has been shown to be associated with poorer outcomes after standard R-CHOP induction therapy. Approximately 70% of DEL will relapse within 5 years. The subsequent traditional approach with potential for cure has been high dose chemotherapy followed by autologous hematopoietic stem cell transplantation (ASCT). Whilst factors such as remission status after front-line treatment and early relapse have been associated with poorer outcomes after ASCT, data are limited regarding significance of DEL status on survival outcomes post-ASCT. We retrospectively studied the prognostic impact of DEL status on outcomes in patients with relapsed or refractory (R/R) DLBCL who underwent ASCT. Methods This was a retrospective, nationwide study of adults patients, >18 years old, with R/R DLBCL who underwent autologous hematopoietic stem cell transplantation (ASCT) between 2010 and 2022 at the only 2 transplant centers in Singapore - Singapore General Hospital and National University Cancer Institute. Patients with double/triple hit lymphoma, defined as concurrent rearrangements of MYC and BCL2 and/or BCL6 by fluorescence in situ hybridization (FISH) analysis, were not included in this study. Patients with transformed indolent B-cell NHL (non hodgkin lymphoma), primary mediastinal B-cell lymphoma, primary CNS (central nervous system) lymphoma, or Richter transformation of chronic lymphocytic leukemia were excluded. Only patients that had available MYC and BCL-2 immunohistochemistry (IHC) were included in this study. Overall survival (OS) and progression free survival (PFS) were estimated using the Kaplan-Meier method. Cox proportional hazards regression models were used to assess associations between covariates of interest and OS or PFS. Results A total of 72 patients were included, 44 (61.1%) non-double expressor DLBCL (non-DEL) and 28 (38.9%) double expressor DLBCL (DEL). Patient demographics and disease characteristics at relapse were similar in both groups aside from a higher incidence of CNS involvement in the non-DEL group as compared to DEL group, 34.1% vs 10.7% (Table 1). Both groups achieved a >90% response (CR and PR) after second-line salvage chemotherapy as well as a >90% response post-transplant (CR and PR). Patients with DEL however were more likely to relapse post-transplant, 69.7% vs 40.9% (p = 0.032) and were also associated with increased odds of all-cause mortality, 60.7% vs 36.4% (p=0.043). This significance was maintained on multivariable analysis, HR 4.22 95% CI 1.20 - 14.84 (p=0.025) and HR 4.32 95% CI 1.10 - 17.15 (p=0.038) respectively. The median follow up for survivors were 42 months (range, 26 to 64 months) in the DEL patients and 60 months (range, 46 to 88 months) in the non-DEL patients. The 5-year PFS in patients with DEL was inferior to non-DEL patients, 23.3% vs 49.6% respectively, p=0.022. DEL patients were also associated with inferior 5-year OS, 40.2% vs 65.7%, p=0.041. In multivariable model, DEL status remained significantly associated with inferior PFS and OS. We also observed that patients with CNS involvement at relapse had inferior PFS and OS. Male gender and a less than complete metabolic response (CR) status prior to transplant, assessed on PET-CT, was also associated with inferior OS. Conclusion Co-expression of C-MYC/BCL2 was associated with inferior outcomes after ASCT in patients with R/R DLBCL. While ASCT has been the standard curative approach in the R/R setting, considerations for novel targeting therapies to achieve a deeper response prior to transplant or the upfront use of chimeric antigen receptor T-cell therapy at first relapse may be further explored in this high-risk subset of patients.

Screening Cerebrospinal Fluid for Aggressive B-Cell Lymphoma: Significance of Clonal Populations Found with 8-Color Flow Cytometry

Background: Secondary central nervous system (CNS) lymphoma confers a poor prognosis, and prompt identification is critical for guiding management. Over the last decade, we have employed cerebrospinal fluid (CSF) analysis with 8-color flow cytometry (FCM) in screening patients deemed at risk of CNS relapse. However, there is little data to guide interpretation and management of positive results, and concurrent clinical and radiographic features of FCM positive (FCM+) patients, remain areas of uncertainty. Methods: We analyzed newly diagnosed (ND) and relapsed/refractory (R/R) diffuse large B cell lymphoma (DLBCL) and high grade B cell lymphoma (HGBCL) patients who underwent a screening lumbar puncture (LP) from 2011-2020. Clinical, imaging, and CSF findings (differential, cytology, FCM) were collected. Patients with prior CNS involvement or FCM showing CLL/low-grade B-NHL were excluded. “FCM-only” patients were defined as FCM+ but without any other evidence of CNS spread (negative cell count/cytology, MRI, and no symptoms), whereas others were deemed to have overt CNS disease. Results: There were 415 LPs among 361 patients (243 ND, 172 R/R). 21 (5%) patients were FCM+, 10 ND and 11 R/R patients (Table 1). Four had FCM-only involvement (2 ND, 2 R/R). Among these, the clonal population was 1.63% of WBC (range, 0.3-2.7%), and 3 had concurrent bone marrow (BM) or peripheral blood (PB) involvement. All 4 received intrathecal (IT) therapy. At median follow up of 23 months, 3 (75%) have died (2 from CNS disease progression, 1 unknown due to loss in follow up), and 1 remains alive in remission 44 months later following IT methotrexate (MTX) and CAR T-cell therapy. 17 had overt CNS disease (8 ND, 9 R/R). The clonal population was 9% (range, 0.2-98%). Eight (47%) had concurrent BM or PB involvement. Twelve (70%) received IV high dose MTX, and the remainder received only IT therapy. At median follow up of 42 months, 9 (53%) have relapsed (2 CNS only, 1 systemic, 6 both), and 9 have died. Median time to CNS relapse was 5 months. Conclusions: CSF 8 color FCM screening of DLBCL/HGBCL patients yields a low proportion of positive results, mostly in the setting of overt CNS disease. However, even FCM-only patients had poor outcomes (2/4 with CNS progression), suggesting that blood contamination does not explain CSF findings, and that these patients should be approached as secondary CNS involvement. Better pt selection for CSF screening is needed to reduce unnecessary LPs. Intensified or novel approaches for all FCM+ patients are needed.

Baseline Immunoglobulin G and Immune Function in Lymphoma: A Retrospective Analysis

Introduction: Non-Hodgkin's lymphoma (NHL) encompasses a diverse group of lymphoma subtypes with a wide range in disease course. Previous studies show that hypogammaglobulinemia in treatment-naïve patients is associated with poorer survival in high grade B-cell non-Hodgkin's lymphomas, though data is lacking on how this applies across all B-cell lymphoid malignancies. We conducted a retrospective study of immunoglobulin levels and clinical outcomes including survival, hospitalization, and infection rates in patients diagnosed with B-cell non-Hodgkin lymphomas of all grades at our institution. Methods: Patient data was collected from January 2010 to June 2022. Two-hundred twenty-three adults (aged > 18 years) with available pre-treatment IgG levels were selected, with hypogammaglobulinemia defined as IgG< 500 mg/mL. For this analysis, DLBCL (n=90), Primary CNS (n=5), and Burkitt's lymphoma (n=1) was classified as high-grade, while CLL (n=52), mantle cell (n=20), marginal zone (n=25), follicular (n=21), and lymphoplasmacytic lymphomas (n=5) as low-grade. Baseline clinical, staging, and laboratory information was collected including hospital admissions, date of death, and number of infections. Preliminary results for overall survival, 3-year survival and 5-year survival were also analyzed. Multivariate logistic models were used to predict outcomes dichotomized for baseline IGG and high/low grade cancers. Kaplan-Meier estimates and Cox model were performed to analyze the overall survival data. Results: The incidence of pre-treatment hypogammaglobulinemia was 47% in the high-grade B-cell lymphoma cohort and 57% the low-grade B-cell lymphoma cohort (p=.9371). Across all NHL subtypes, individuals with baseline IgG< 500 showed an increased rate of hospitalization (4.453, CI: 1.955-10.54, p= 0.0005) and higher mortality (3.325, CI:1.258, 8.491, p= 0.013), yet no association in number of infections when compared with those with IgG>500. There was no statistical difference in patients' hospitalization rate when they were treated with IVIG only, rituximab only, or a combination (p=.141792). Additionally, there was no statistically significant correlation with COVID infections when evaluating grade of lymphoma (p=.8527) or IgG level (p=.6535). There was no statistically significant difference in individuals who were alive after three years and five years in those with baseline IgG<500. Discussion: Our study is the first to analyze incidence of hypogammaglobulinemia at time of diagnosis of NHL as a potential biomarker of interest for future outcomes including hospitalization and infection. These findings demonstrate an association between hypogammaglobulinemia when comparing the rate of hospitalization and mortality across the spectrum of B-cell NHL. This effect was further amplified in patients with aggressive B-cell lymphoma. Given the common use of monoclonal antibodies to treat B cell lymphomas of all subtypes and the known risk of hypogammaglobulinemia from these treatments and the common finding of hypogammaglobulinemia at diagnosis of B cell NHL, pretreatment screening of IgG levels may be important to identify patients at risk for infection, hospitalization and death. Further clinical equipoise exists requiring a randomized clinical trial to indicate the use as a prognostic factor for infection, hospitalization, and mortality.

Racial and Ethnic Disparities for Primary CNS Lymphoma: A National Cancer Database Analysis with Emphasis on Hispanics

BACKGROUND Primary central nervous system lymphoma (PCNSL) is an aggressive, extra nodal non-Hodgkin lymphoma (NHL), that accounts for ~4% of newly diagnosed central nervous system (CNS) tumors and 1-2% of all NHL. ( Blood PMID 26980727). The majority of PCNSL tumors are of the highly aggressive diffuse large cell subtypes, usually of B-cell phenotypic origin ( J Clin OncolPMID 28640701). Treatment survival remains heterogenous due to biologic differences and racial disparities. Multiple epidemiological studies have evaluated racial differences, with heterogenous results. There are published reports of culturally and ethnically diverse populations from high-income countries, showing statistically significant differences in PCNSL incidence and survival rates among different ethnicities ( Neuro OncolPMID 19273630), but there are no studies comparing Hispanics (HI) and Non-Hispanics (NH). This National Cancer Database (NCDB) analysis aims to provide information on how demographic, clinical, and survival outcomes differ in HI versus NH patients with PCNSL. METHODS Data were analyzed on PCNSL patients in the US reported to the NCDB between 2004 and 2019. Demographic and treatment characteristics were compared between ethnic groups. Kaplan-Meier and Cox regression analyses were used to compare OS between HI and NH populations. Multivariate analysis and propensity score matching was performed with adjustment for age, stage, co-morbidity score, and insurance status, type of facility and great circle distance. RESULTS Of 15908 PCNSL patients, 8% were HI, and 87% NH. 58% of HI were male, compared to 50% in NH. As compared to NH at diagnosis, HI pts were younger (mean 60 years vs. 67 years) (p<0.001); the majority of HI (59%) were diagnosed in the age of <65 vs majority of NH (45%) who were diagnosed in the age bracket of 65-70 (p<0.001). Regarding race, most of HI and NH were whites (92% vs 85%), followed by blacks (0.9% vs 7.3%). When examining insurance type; Government Sponsored was the most prevalent type in HI vs NH (56% vs 61%), followed by private insurance (29% vs 33%). The most non-Insured group was HI (12%) vs NH (2%). Regarding Census Median Income (2008-2012), the most prevalent bracket (29%) for HI was $48,000 - $62,999, and for NH (36%) $63,000 +. When looking at median income of less than $38,000, HI were 25% vs NH 14%. Regarding Charlson-Deyo Score (comorbidities score), HI had 20% =/> 2 score, vs NH 16%. (p<0.001). Academic/Research Programs, including NCI-designated comprehensive cancer centers, was the most prevalent type of facility providing care for both HI (49%) and NH (50%). Regarding the median distance in miles between the patient's residence and the hospital that reported the case (Great Circle Distance), HI lived at a median of 9.7 miles, vs NH at median of 14.7 miles. On survival analysis, the survival probability at 2, 5 and 10 years of HI vs NH were (54% vs 47%), (43% vs 34%), and (32% vs 22%), respectively. The median survival time (MS) was 3 years for HI, vs 1.6 years for NH; and there was an overall survival (OS) difference favoring HI with (p<0.0001). Independently, on multivariate analysis, not insured status was associated with worse OS (HR 1.22, CI 1.02-1.47, p<0.01) and private insurance type was associated with better OS (HR 0.82, CI 0.73-0.93, p<0.01). Interestingly, the propensity matched analysis demonstrated significant MS difference between HI vs NH (median 1.64 years vs. 1.43 years; p<0.01). CONCLUSION In this data analysis from the NCDB between 2004-2019, HI with PCNSL have dissimilar outcomes when compared to NH. There were statistically significant differences between HI and NH in age at diagnosis, median income, and higher Charlson-Deyo Score. There were statistically significant differences in MS, survival at 2, 5, and 10 years and OS favoring the HI cohort. Unique and heterogeneous characteristics from HI may explain why there is an increase in OS after PCNSL diagnosis in this cohort of patients, with differences mainly arising from HI being diagnosed at a younger age and living closer to the treatment facilities as compared to NH. As personalized therapies for PCNSL are being developed, equitable access including clinical trials should be advocated for resource-limited settings as well as aiming at studying biologically characteristics of HI with PCNSL to better understand and improved outcomes in all cohorts.

Cerebrospinal Fluid IL-6 Plus IL-10 As Effective Diagnostic Biomarkers for Secondary Central Nervous System Lymphoma

Background : Secondary central nervous system lymphoma (SCNSL) characterized by the involvement of the CNS at initial diagnosis of systemic lymphoma or in the setting of relapse. Accurate diagnosis and therapeutic response of SCNSL are particular challenges, which need to be improved. We aimed to evaluate the diagnostic and the post-therapeutic prognostic value of cerebrospinal fluid (CSF) cytokine in patients with SCNSL. Methods: In this retrospective study involving 234 NHL patients and 53 other CNS patients, the NHL patients was divided into two sub-groups based on with and without CNS involvement: SCNSL (n=57) and non-SCNSL (n=177). The CSF cytokine profiles (interleukin (IL)-2, -4, -6, and -10, tumor necrosis factor-α, interferon-γ, and IL-17A) of these patients were measured by cytometric bead assay and evaluated the ability of CSF cytokine levels as diagnostic, therapeutic and prognostic biomarkers for SCNSL. Results: CSF IL-6 and IL-10 levels were significantly higher in SCNSL patients than non-SCNSL and other CNS patients. CSF levels of IL-6 and IL-10 were significantly higher in patients with an stage at Ⅲ and Ⅳ, CSF WBC counts>5/µL, CSF protein ≥0.45g/L.Using a CSF IL-6 cut-off value of 10.13 pg/ml yielded a diagnostic sensitivity and specificity was 62.34% and 87.57%, respectively (AUC, 0.7798; 95% CI, 0.7083 to 0.8514); For a CSF IL-10 cutoff value of 7.82, the sensitivity was 76.23%, and the specificity was 98.31% (AUC, 0.8164; 95% CI, 0.7466 to 0.8862). Combined CSF IL-6 and IL-10 significantly improved the diagnostic effect of SCNSL (AUC, 0.8959; 95% CI, 0.8371 to 0.9547). The levels of IL-6 and IL-10 in cerebrospinal fluid of SCNSL patients who responded to intrathecal chemotherapy were significantly decreased during follow-up, while the levels of these two cytokines showed fluctuating changes in patients with progressive SCNSL. Moreover, poor Progression free survival (PFS) for patients with SCNSL was associated with the increased CSF IL-10 level at diagnosis with CNS involvement (P=0.035), but not with the increased CSF IL-6 level. Conclusion: Our study confirmed CSF level of IL-6 and IL-10 were potentially effective diagnostic biomarkers for SCNSL, and poor progression free survival (PFS) for patients with SCNSL was associated with the increased CSF IL-10 level.

Glofitamab in Aggressive B Non-Hodgkin Lymphoma (B-NHL): A Real World Experience

Background Glofitamab is a bispecific monoclonal antibody that targets CD20 and CD3, with a unique 2:1 (bivalency for CD20; monovalency for CD3) configuration. In the pivotal trial leading to regulatory approval 1, glofitamab demonstrated remarkable efficacy in patients with relapsed or refractory diffuse large B cell lymphoma (DLBCL). Objective responses were observed in 80% of patients, with 39% achieving complete response. Additionally, complete response was maintained in 78% of patients at 12 months, suggesting that the response might be durable. Most grade 3 or 4 adverse events were hematologic in nature and generally manageable. Despite its efficacy in clinical trials, the real-world safety and efficacy of glofitamab have not been extensively studied, particularly in patient groups such as those with prior exposure to hepatitis B virus (i.e. occult HBV infection, as evidenced by positive anti-HBV core antigen antibody). Here, we report a single-institution experience of glofitamab in Chinese patients with relapsed or refractory DLBCL, with one-third of them having occult HBV infection. Methods This is a retrospective study to evaluate the safety and efficacy of glofitamab in Chinese patients with relapsed or refractory DLBCL. Patients were enrolled through a compassionate program and were required to have failed at least three prior lines of therapy. Patients with active central nervous system lymphoma or active HBV infection (defined as detectable serum hepatitis B surface antigen) were ineligible for treatment. Glofitamab was administered according to the published protocol, with obinutuzumab given on the first day to mitigate the severity of cytokine release syndrome (CRS). Patients with occult HBV infection were given antiviral prophylaxis with entecavir. Positron emission tomography/computerized tomography (PET-CT) was performed after at least two cycles of treatment for response evaluation. Response assessment was made according to published criteria 2. Survival was analyzed using Kaplan-Meier method. Statistical calculations were performed with SPSS Statistics version 28. Results Nine men and six women at a median age of 60 (range: 41-83 years) were treated. Underlying diseases were DLBCL (N=12;80%); transformed follicular lymphoma (N=1, 7%); transformed marginal zone lymphoma (N=1, 7%); and high-grade B-cell lymphoma (N=1, 7%). Other relevant features included staging (I, N=1, 7%; II, N=1, 7%; IV, N=13, 87%); cell of origin (germinal centre B-cell: N=7, 47%; non-germinal centre B-cell: N=7, 47%; not available: N=1, 7%); double-expressor status (positive: N=9, 60%; negative: N=1, 7%; unknown: N=5, 33%); double-hit status(positive: N=3, 20%; negative: N=3, 20%;, unknown: N=9, 60%), prior lines of therapy (median: 6, range: 3-8); prior chimeric receptor T-cell therapy (N=7, 47%); prior autologous transplant (N=4, 27%); elevated serum lactate dehydrogenase (N=9, 60%), and occult HBV infection (N=5, 33%). Eleven patients had a response assessment, showing complete response N=6, 55%), partial response (N=1, 9%) and no response/progressive disease (N=4, 36%). At a median follow-up of 7 months (range 1-22 months) (Figure 1), the median progression-free survival (PFS) was 12 months and the median overall survival (OS) was 15 months(Figure 2). Adverse events included >= grade 3 haematological (anaemia: N=7, 47%; neutropenia: N=8, 53%; thrombocytopenia: N=5, 33%); CRS (grade 1: N=4, 27%; grade 2: N=3, 20%); and cytomegalovirus retinitis (N=1; 6%). Conclusion Glofitamab showed similar efficacy in real-world patients compared with published results. It was safe in patients with occult HBV infection given antiviral prophylaxis. Reference: 1. Dickinson MJ, Carlo-Stella C, Morshhauser F, et al. N Engl J Med 2022; 387:2220-2231 2. Cheson BD, Fisher LI, Barrington SF, et al. J Clin Oncol 2014; 32: 3059-3067

A Population-Based Study on Performance of Clinical Prognostic Models in Patients with Diffuse Large B-Cell Lymphoma Younger Than 70 Years

Background: In diffuse large B-cell lymphoma (DLBCL), the International Prognostic Index (IPI) and age-adjusted IPI (aaIPI) remain the primary prognostic tool for outcome predictions and risk stratification in clinical trials. Several prognostic indices with the same five risk factors included in the IPI have been developed for DLBCL patients, including Revised IPI (R-IPI) and National Comprehensive Cancer Network IPI (NCCN-IPI), showing a decreased prognostic value of the IPI. Additionally, an age-adjusted DLBCL-Prognostic Index (aaDLBCL-PI) developed in patients younger than years combining similar variables (excluding age and stage), but with the addition of albumin, showed better accuracy than the IPI. Younger patients without comorbidities and a history of cancer are typically candidates for clinical trials, but validation studies of prognostic indices in this population are mostly lacking. Aim: This study aimed to compare five clinical models (IPI, aaIPI, R-IPI, NCCN-IPI, and aaDLBCL-PI) in patients with DLBCL younger than 70 years identified from the Danish Lymphoma Registry (LYFO). Methods: Patients diagnosed between 2000 and 2021 and identified through the LYFO were included if they fulfilled the following criteria: 1) newly diagnosed DLBCL; 2) age <70 years; 3) treated with at least one cycle of immunochemotherapy (R-CHOP/R-CHOP-like); 4) availability of all parameters for calculation of all five prognostic models; and 5) no previous/concomitant malignancy (excluding non-melanoma skin cancer). Patients with isolated central nervous system lymphoma were excluded. Discriminatory ability was calculated using the concordance index (c-index), with 1 indicating perfect discrimination and 0.5 indicating random guess. Model fitness was compared with the Akaike Information Criterion (AIC), with the lower values indicating a better fit of a model and the difference ≥10 between models indicating a significant improvement in model fitness. Results: Of 3,184 DLBCL patients younger than 70 years, 2,456 had all parameters available for calculating five prognostic models and were included in the final analysis. The median age at diagnosis was 59 years (range 18-69) with a slight male predominance (n=1,440, 58.6%). Most patients (n=1,619, 65.9%) had advanced (III/IV) stage of disease and were in good performance status 0-1 (n=2,165, 88.2%). More than one extranodal localization was diagnosed in 738 patients (30%), and more than half of our population (n=1,462, 59%) had elevated LDH levels. All models stratified patients into four risk groups except R-IPI, which provided three risk groups. The proportion of patients allocated to the low-risk group according to the IPI, aaIPI, R-IPI, aaDLBCL-PI, and NCCN-IPI were 32.9%, 19.7%, 12.3%, 17.4%, and 15.3%, respectively. The lowest proportion of patients in the high-risk group was identified by NCCN-IPI (6.3%), followed by IPI (14.8%), aaIPI (20.2%), aaDLBCL-PI (22.0%), and R-IPI (40.7%), respectively. The median follow-up was 78.1 months (range 0.2-244 months). As presented in Table 1, NCCN-IPI produced the highest absolute 3- and 5-year difference between high and low-risk groups and was the only model with less than 50% of surviving patients in the high-risk groups in respective survival time points. Moreover, the highest c-index was calculated for NCCN-IPI (0.709), followed by IPI (0.703), aaDLBCL-PI (0.692), R-IPI (0.679), and aaIPI (0.667). NCCN-IPI showed a statistically significant difference in discriminatory ability compared to all models except IPI. The lowest AIC was found in NCCN-IPI (9,231), along with IPI (9,295), aaDLBCL-PI (9,369), R-IPI (9,310), and aaIPI (9,408). When patients aged ≤60 were selected (n=1,328), NCCN-IPI again produced the highest absolute 3- and 5-year difference between high and low-risk groups. Moreover, NCCN-IPI had the highest c-index and lowest AIC (0.758; 3,068) compared to IPI (0.742; 3,118), aaIPI (0.730; 3,124), R-IPI (0.729; 3,109), and aaDLBCL-PI (0.751; 3,110). Conclusion: In this retrospective population-based study investigating 2,456 patients with DLBCL 18-69 years of age, we found NCCN-IPI superior to IPI and, in particular, aaIPI and R-IPI. Therefore, we suggest reporting NCCN-IPI and IPI for risk stratification in future studies and clinical trials.

Efficacy and Safety of BTK Inhibitors in Vitreoretinal Lymphoma: A Single-Center, Retrospective Analysis of 24 Patients

Background: Vitreoretinal lymphoma (VRL) is a special subtype of rare central nervous system lymphoma (PCNSL). Most of the pathologic types are diffuse large B-cell lymphoma of non-germinal central origin. Currently, the optimal treatment strategy for VRL is not clear, and the traditional treatment usually includes about 20 repeated intravitreal injections of low doses of methotrexate or intraocular local radiotherapy. Eventually, however, 60-90% of VRL will progress to PCNSL. Therefore, CNS prophylaxis of VRL patients is very important. A previous prospective clinical study of our research group (including 10 VRL patients) confirmed that single-drug BTK inhibitors can replace repeated intravitreal injection of low doses of methotrexate, with rapid effect, high safety, and certain value in preventing CNS progression. Methods: In order to further clarify the efficacy and safety of BTK inhibitors in VRL patients, we included 24 VRL patients who were consecutively admitted to the Hematology Department of Beijing Tongren Hospital from May 2020 to December 2022, and retrospectively analyzed their clinical features, treatment methods, treatment outcomes, survival status and treatment-related adverse reactions. Results: Of the 24 patients, 14 were female and 10 were male, with a median age of 62 years old (36-75). There were 18 patients with primary VRL (PVRL) and 6 patients with secondary VRL (SVRL) to PCNSL. The IL-10 in aqueous humor/vitreous fluid at baseline was significantly increased in all patients (362.1±89.5pg/mL), and the IL-10/IL-6 ratio was greater than 1. Except for one patient with both uncontrolled PCNSL and VRL, the other 23 VRL patients showed no evidence of CNS involvement by brain MRI and cerebrospinal fluid detection. All 24 patients were treated with a BTK inhibitor (Zanubrutinib 160mg bid, or Orelabrutinib 150mg qd), of whom, 9 VRL patients were also treated with intravitreal methotrexate injection (0.4mg/ time, weekly ×12 times → monthly ×9 times) concurrently, and the remaining 15 patients did not receive any antitumor therapy other than BTK inhibitors. After 1 month of treatment with BTK inhibitors, the efficacy was evaluated by slit lamp microscope, optical coherence tomography (OCT), and aqueous humor cytokines. 21 patients achieved CR (87.5%), 2 PR (8.3%), and 1 PD (progression of CNS lesion but improvement of intraocular disease). The IL-10/IL-6 levels in aqueous humor were lower than 1 in all 24 patients 1 month after treatment, and the IL-10 levels in aqueous humor were slightly higher than the normal range in two patients. The median duration of BTK inhibitors use was 10 months (1.5-23.0 months). At a median follow-up of 17 months (5.4-31.5 months), 15 patients (62.5%) developed disease progression, including 11 patients (45.8%) with CNS progression and 4 patients (16.7%) with intraocular recurrence. The median progression-free survival (PFS) time was 11.9 months, and the median overall survival (OS) time was not reached. The 1-year and 2-year PFS rates were 34% and 26%, and the 1-year and 2-year OS rates were 96% and 82%, respectively. The recurrence rate was 33.3% in the combined treatment group and 80.0% in the BTK inhibitors monotherapy group. A total of three patients died, all due to CNS progression. BTK inhibitors were generally well tolerated in VRL patients, with no adverse reactions that led to treatment discontinuation. 4 patients had grade 1-2 hypertension (16.7%), 1 patient had grade 1 hypotension (4.2%), 2 patients had grade 1 joint pain (8.5%), and 6 patients had grade 1 subcutaneous hemorrhage and ecchymosis (25.0%). Four patients developed COVID-19 infection while taking the drug and the drug was suspended. All four patients recovered from COVID-19 infection within 2 weeks and did not develop significant pneumonia. Conclusion: This is the largest report regarding the use of BTK inhibitors in VRL patients. BTK inhibitor has a rapid local control effect on VRL and is well tolerated. However, BTK inhibitors monotherapy has unsatisfied preventive effect on the CNS, and it is still necessary to explore the value of combinational therapy, such as combined BTK inhibitors and high-dose methotrexate.

Radiotherapy Combined Chimeric Antigen Receptor T-Cells Therapy in Relapsed or Refractory Diffuse Large B-Cell Lymphoma（R/R DLBCL）

Background: CAR (chimeric antigen receptor) T-cell therapy has transformed the treatment of patients with recurrent or refractory hematological malignancies. However, some patients cannot benefit from CAR-T cell therapy. Radiation therapy (RT) can induce immune effects and has synergistic effects in combination with other treatments. With the help of RT's immunomodulatory effects, a successful bridging strategy can be developed. This study aimed to investigate the efficacy and safety of CAR-T combined radiotherapy in patients with relapsed or refractory diffuse large B-cell lymphoma (R/R DLBCL). Methods: We retrospectively analyzed the clinical data of 57 R/R DLBCL patients who received radiotherapy combined CAR-T therapy in Tongji Hospital of Tongji University between January 2018 and February 2023 (NCT02537977). 18 Patients (31.58%) received radiation therapy within 1 year before CAR-T therapy and 1 patient (1.75%) received radiation therapy 1 month later after CAR-T therapy. Patients were divided into two groups: CART group and CAR-T+RT group. Clinical features, treatment response and incidence of adverse events of 57 patients were collected and analyzed to demonstrate the efficacy of CAR-T combined radiotherapy in patients with R/R DLBCL. Results: Of the 57 patients with R/R DLBCL treated with CAR-T therapy, 19 patients (33.33%) received CAR-T combined radiotherapy. The overall response rate (ORR) is 63.00% and 35.80% for patients in CAR-T+RT group and CAR-T group, respectively. The response rate is better for patients in CAR-T+RT group than that of CAR-T group P=0.05). One-year overall survival (OS) is 72.40% (95%CI, 61.90-82.90% ) for patients in CAR-T+RT group, while 1-year OS is 47.40% (95%CI, 39.30-55.50%) for patients in CAR-T group. The median progression-free survival (PFS) is 91 days (95%CI, 35.12-146.88) for patients in CAR-T group and the median PFS is not reached for patients in CAR-T+RT group. There is significantly different in OS and PFS for patients in CAR-T+RT group and CAR-T group ( P=0.02 and P=0.01). Only one patient with CNS lymphoma developed grade 4 CRES. 9 patients (47.37%) occurred grade 1-2 CRS, no patient occurred ≥grade 3 CRS for patients in CAR-T+RT group; 2 patients (3.51%) occurred grade 3 CRS, 25 patients (65.80%) occurred grade 1-2 CRS, no patient occurred grade 4-5 CRS for patients in CAR-T+RT group. Conclusion ： Our study shows that CAR-T combined radiation therapy can obtained better remission rate for R/R DLBCL patients. It is also can effectively prolong PFS and OS, improving the survival of patients. Radiotherapy combined with CAR-T therapy showed efficacy and manageable tolerability, making it a promising treatment option for patients with R/R DLBCL.

Anti CD161 Antibody IMT-009 Is a Novel Immunotherapeutic Agent That Effectively Blocks the Inhibitory CLEC2D/CD161 Axis in CLEC2D+ B Cell Hematological Malignancies Reinvigorating T and NK Cell Function Leading to Anti-Tumor Benefit

Background: The CLEC2D/CD161 axis is a ligand-receptor pathway that has been shown to inhibit both T and NK cell function 1,2. CD161 is a C-type lectin-like receptor, which is expressed on NK cells and subsets of both CD4 + and CD8 + T cells. The tumor infiltrating CD161+ T cells have high cytotoxic potential and display an NK cell-like signature 2. Its ligand CLEC2D is expressed on the surface of both malignant cells and immune cells including germinal center B cells, activated T cells and tumor associated macrophages. Owing to its expression in germinal center B cells, CLEC2D is highly expressed in multiple types of B cell lymphomas including Diffuse Large B Cell Lymphoma (DLBCL), Follicular Lymphoma and Burkitt lymphoma 3. Furthermore, subset of infiltrated T cells in these lymphomas are CD161+ making this axis a promising novel target for immunotherapeutic intervention in hematological malignancies (Fig1). Immunitas has developed IMT-009, a monoclonal, Fc silent, fully human IgG1, high affinity antibody to CD161 that selectively blocks its interaction with CLEC2D. We show that IMT-009 effectively reverses CLEC2D-mediated inhibition and restores NK cell and T cell functions, including antigen specific T cell mediated cytotoxicity to lymphoma cell lines. Furthermore, IMT-009 shows monotherapy benefit in reducing tumor burden in a human B cell lymphoma model engrafted in humanized mice in vivo. IMT-009 is currently being evaluated in a Phase 1/2a clinical trial in both solid tumors and heme malignancies. Results: IMT-009 is a highly selective antibody to CD161 that strongly blocks its interaction with CLEC2D. In presence of CLEC2D-expressing target cells, NK cell degranulation, cytokine production and cellular cytotoxicity towards lymphoma tumor targets is highly suppressed which is overcome by treatment with IMT-009. Similarly, IMT-009 reversed CLEC2D-mediated inhibition and restored T cell activity (TCR signaling, cytokine production) in a Jurkat cell reporter system, and enhanced polyfunctionality of primary antigen-specific human T cells shown by secretion of TNF-α, IL-2, and IFN-γ, and direct T cell mediated cytotoxicity. IMT-009 also released CD161-mediated suppression of antigen recall response by PBMC derived effector memory CD161+ CD4+ T cells, resulting in an increased frequency of CD161+ IFN-γ+ cells and an increase in their proliferation. These data together show that IMT-009 is highly effective in overcoming CLEC2D mediated suppression of both T and NK cell functions. To prioritize indications that will likely benefit from IMT-009, we performed IHC for CLEC2D in a diverse set of tumor indications and found that B cell lymphomas of various subtypes have high CLEC2D protein expression by H score. Also, DLBCL was found to have the second highest median RNA expression of CLEC2D in TCGA. Furthermore, analysis of publicly available single-cell RNA-sequencing (scRNA-seq) data from B cell lymphoma including CNS lymphoma revealed CLEC2D to be highly expressed within the B lineage cells including the abundant malignant cell population (Fig2). KLRB1 (gene encoding for CD161) was also found to be expressed on a subset of tumor infiltrating CD4 and CD8 T cells in these datasets (Fig2). To confirm this, we tested CD161 expression in B cell lymphomas by immunofluorescence. Results showed CD161+ cells infiltrated in Hodgkin Lymphoma, and post-R-CHOP treated DLBCL, highlighting the potential sensitivity of these malignancies to IMT-009 treatment. Together, these results indicate that B cell lymphomas may exhibit an immunosuppressive environment mediated by the CLEC2D/CD161 axis. To test the anti-tumor benefit of IMT-009 in a human B cell lymphoma model, we treated CD34+ humanized mice implanted with Raji, a Burkitt lymphoma cell line with IMT-009. The group of mice treated with IMT-009 had a mean tumor growth inhibition of 35% and the anti-tumor response correlated with increased frequency of CD161+ T and NK cells. We further show that IMT-009 can synergize with Rituximab in NK cell mediated killing of B cell lymphoma cell lines in vitro. Conclusion: B cell malignancies tend to respond poorly to anti-PD-1 therapy 4,5. This lack of efficacy could be driven by a highly immunosuppressive environment mediated by the CLEC2D/CD161 axis. Our results support evaluation of IMT-009 as a novel cancer immunotherapy to disrupt CLEC2D/CD161 signaling, with strong therapeutic potential in lymphomas.

Lisocabtagene Maraleucel (liso-cel) in Patients (Pts) with R/R MCL: Subgroup Analyses in Pts with High-Risk Disease Features from the MCL Cohort of the TRANSCEND NHL 001 Study

Background: Pts with R/R MCL after ≥ 2 prior lines of therapy, including a Bruton tyrosine kinase inhibitor (BTKi), have poor prognosis. Among pts with R/R MCL, several high-risk disease features are associated with a worse prognosis, including TP53 mutation, high proliferation index (Ki-67 ≥ 30%), blastoid morphology, and secondary CNS involvement. Liso-cel is an autologous, CD19-directed, 4-1BB CAR T cell product administered at equal target doses of CD8 + and CD4 + CAR + T cells. In the primary analysis of the MCL cohort from the phase 1, seamless design TRANSCEND NHL 001 study (NCT02631044), liso-cel treatment resulted in a rapid, high rate of durable CRs with a manageable safety profile in pts with heavily pretreated R/R MCL. Here we report the outcomes in pts with R/R MCL from prespecified subgroup analyses based on high-risk disease features. Methods: Eligible pts had PET-positive R/R MCL after ≥ 2 lines of prior therapy, including a BTKi, alkylating agent, and CD20-targeted agent. Pts received liso-cel at a target dose of 50 × 10 6 or 100 × 10 6 CAR + T cells after lymphodepleting chemotherapy. Bridging therapy was allowed. Primary endpoints were treatment-emergent AEs (TEAE) and ORR by independent review committee (IRC) per Lugano 2014 criteria; secondary endpoints included CR rate, duration of response (DOR), PFS, and OS. The liso-cel-treated set included all pts who received liso-cel. The efficacy analysis set included all pts in the liso-cel-treated set who had PET-positive disease per IRC at baseline. Results: Of 104 leukapheresed pts, 88 received liso-cel. Median on-study follow-up was 16.1 mo (range, 0.4-60.5). Median age was 68.5 y (range, 36-86) and median prior systemic lines of therapy was 3 (range, 1-11). Among liso-cel-treated pts, 66 (75%) had Ki-67 ≥ 30% and 15 (17%) had Ki-67 < 30% (Ki-67 was not reported in 7 [8%] pts); 20 (23%) had a TP53 mutation present and 34 (39%) did not ( TP53 mutation was indeterminate in 4 [5%] pts and not reported in 30 [34%] pts); and 27 (31%) had blastoid morphology and 48 (55%) did not (blastoid morphology was not reported in 13 [15%] pts). Most pts with these high-risk disease features also had disease that was refractory to last therapy, was refractory to prior BTKi, and had a complex karyotype. A total of 7 (8%) pts had secondary CNS lymphoma, of which 5 had refractory disease, 5 had Ki-67 ≥ 30%, and 1 each had TP53 mutation and blastoid morphology. Response rates, PFS, and OS across subgroups were consistent with the overall population, with high ORR and CR rate that was durable and high PFS and OS (Table 1). Although a limited number of pts had TP53 mutation assessed, pts with TP53 mutation had a numerically lower median DOR than the overall population, likely due to a higher proportion of objective responders achieving a PR than CR; however, pts with TP53 mutation who achieved CR had durable responses with 6 of 11 pts in an ongoing response at data cutoff. Among the 7 pts with secondary CNS lymphoma, response rates were high (ORR, 86% [n = 6]; CR rate, 71% [n = 5]), and 3 of 5 pts who achieved CR were in an ongoing response at data cutoff. Safety outcomes across subgroups were generally consistent with the overall population (Table 2). Most cytokine release syndrome (CRS) and neurological events (NE) were low grade in all subgroups, similar to the overall population (any-grade CRS, 61% [grade 3-4, 1%]; any-grade NEs, 31% [grade 3-4, 9%]; and no grade 5 CRS or NEs). Incidences of other TEAEs of special interest were also similar among subgroups. Of the 7 pts with secondary CNS lymphoma, 5 had low-grade CRS and 3 had low-grade NEs with no grade ≥ 3 CRS or NEs reported; 1 pt had a grade ≥ 3 infection. Cellular kinetics and B-cell aplasia by subgroup will be presented. Conclusions: In these subgroup analyses including pts with R/R MCL and high-risk disease features (Ki-67 proliferation index ≥ 30%, TP53 mutation, blastoid morphology, and secondary CNS lymphoma), liso-cel demonstrated clinically meaningful efficacy across subgroups with durable responses. Efficacy and safety outcomes were generally consistent with the overall study population. While some subgroups were limited by small numbers, these results suggest a favorable benefit/risk profile for liso-cel in pts with R/R MCL and high-risk disease features, a pt population for whom effective treatment options are rarely available.