Citations 663

Effects of Antibiotic Eradication Therapy on H. Pylori-Negative Stage IE Gastric MALT Lymphoma ─ Real World Experience

Blood | December 1, 2023 | Volume: 142 | Issue: Supplement 1 | Pages: 5157-5157

10.1182/blood-2023-174116

Background: Helicobacter pylori (H. pylori) infection plays a critical role in the pathogenesis of gastric MALT lymphoma and its eradication can lead to tumor regression with a complete response (CR) rate of 78% in early-stage disease and a 5-year survival rate > 95%. However, 10% of patients have gastric MALT lymphoma with no detectable H. pylori infection (Zullo et al., J Clin Gastroenterol 2010). There is controversy regarding whether H. pylori-negative gastric MALT patients should receive a trial of antibiotic therapy. The NCCN guideline recommends skipping antibiotics and proceeding directly to radiation therapy. On the other hand, the ESMO guideline recommends H. pylori eradication (HPE) as the first-line therapy for every patient with gastric MALT lymphoma irrespective of H. pylori status. This report aimed to evaluate the effectiveness of H. pylori eradication therapy in patients with limited-stage gastric MALT lymphoma. Methods: A retrospective analysis was performed to identify patients diagnosed with stage IE gastric MALT lymphoma between January 2002 and December 2022. H. pylori infection was determined by immunostaining of gastric mucosa, serology, stool antigen, or urea breath test. H. pylori status was considered positive when at least one of those tests showed positive results and negative when all of the performed test results in that patient were negative. The primary outcome was the CR rate defined as no macroscopic findings of lymphoma and negative biopsy resultsfrom the follow-up endoscopy 3-6 months following completion of treatment. Results: A total of 52 patients were identified; the median age was 68 years (range 52-87), and 29 (55.8%) were male. H. pylori infection was detected in 36.5% (19/52) patients by at least one of the methods - 14 cases by immunostaining, 3 cases by serology, and 1 each by stool antigen and urea breath test. The PCR or FISH for t(11;18) was performed in 10 cases (19.2%) and 2 cases of t(11;18) were detected (both were H. pylori-negative). All 19 H. pylori-positive patients were treated for H. pylori eradication (HPE) and 63% (12/19) achieved a CR. Of the 33 H. pylori-negative patients, 8 (24.2%) received HPE as the initial treatment and 1 (12.5%) responded with a CR. The treatment outcomes after HPE therapy showed the CR rate was significantly higher in H. pylori-positive patients than in H. pylori-negative patients (63.2% vs 12.5%, p=0.033) (Table 1). Only 2 of the 12 H. pylori-positive patients achieving CR have relapsed after a median follow-up of 89.7 months (range 2.9-227.8); the one H. pylori-negative patient that received HPE also remains in CR at 9+ months. The other first-line treatments applied for the 25 H. pylori-negative patients were radiation therapy in 18 (54.5%), single-agent rituximab in 3 (9.0%), surgical resections in 2 (6%), oral chlorambucil in 1 (3%), and observation in 1 (3%) The outcomes are shown in Figure 1. Conclusion: In our United States patient population, the incidence of H. pylori-negative gastric MALT lymphoma was 63%, much higher than previously reported (Zullo et al., J Clin Gastroenterol 2010) and similar to that found by other US investigators (Strati et al. 10.1002/ajh.25447). For limited-stage H. pylori-positive gastric MALT lymphoma, HPE is an effective first-line treatment and should be used. For patients who have no detectable H. pylori infection with multiple methods, the CR rate with HPE is very low in our experience. Although there is likely little harm to trying HPE (as ESMO guidelines suggest), this delays definitive radiation therapy. These data will be useful in patient counseling and treatment decision-making.
Favorable Outcomes of Splenic Marginal Zone Lymphoma in an International Study of 934 Patients with Long Follow-up

Blood | December 1, 2023 | Volume: 142 | Issue: Supplement 1 | Pages: 4396-4396

10.1182/blood-2023-173247

Introduction: Splenic marginal zone lymphoma (SMZL) is a rare, indolent disease. There is no universally accepted standard therapy and long-term outcome data are limited. Rituximab monotherapy is increasingly used over splenectomy in the first-line setting despite a paucity of comparative studies. In the absence of randomized trials, large-scale international real-world data studies are critical to evaluate outcomes of different treatment interventions and to understand the natural history of SMZL in the rituximab-era. Methods: Adult patients with SMZL diagnosed between Jan 1 st 2000 and Dec 31 st 2018 were identified using regional/nationwide population-based registries or hospital registries in Europe, the UK, North America, and Australia. Medical records and pathology reports from eligible patients were reviewed locally by clinicians with specialty experience in hemato-oncology. SMZL cases were required to meet the diagnostic criteria by Matutes et al. Detailed data on clinico-pathological features, comorbidities, treatments (including treatment intention), treatment responses and survival outcomes were entered in a central study database. Overall survival (OS) was defined as time from diagnosis until death from any cause or censoring at last follow-up unless stated otherwise. Event-free survival (EFS) was defined as the time from diagnosis until histological transformation, initiation of new chemotherapy or death from any cause. Survival probabilities were estimated using the Kaplan-Meier estimator. Cumulative risk of transformation was estimated with death as a competing risk. Primary endpoints were 10-year OS and 5-year EFS respectivly. Results: A total of 934 patients from 25 sites were included. Median age at diagnosis was 68 years (IQR 60-76) and 54% were female. Bone marrow involvement was present in 96% (564/590) of those assessed, anemia (Hb <12g/dL for women or <13g/dL for men) in 58%, LDH >UNL in 46%, lymphocytosis (>5 x10 9/L) in 34%, and B-symptoms in 34%. Treatment data were available for 97% of patients. Median follow-up was 9.1 years (range 0-23). Watch and wait was the initial strategy in 28% and 88% of patients received at least one line of treatment during follow-up with the most common being splenectomy (45%), immuno-chemotherapy (19%) or rituximab monotherapy (8%). Fifteen percent received “other” treatments (i.e., combinations of listed therapies and/or radiation). The overall response rate to first-line treatment was 88% (95%CI: 85-90%) with 61% (95%CI: 57-64%) achieving CR. Second line (2L) therapy was needed in 34% during follow-up, 3L in 20% and 4L+ in 9%. The 5-year EFS and OS for all patients were 61% (95%CI: 57-65%) and 77% (95%CI: 74-80%) respectively. The 10-year OS and lymphoma-specific mortality (with non-SMZL deaths as competing risk) estimates were 60% (95%CI: 57-64%) and 11% (95%CI: 9-14%) respectively. The 5-year OS after 2L and 3L were 61% (95%CI: 55-68%) and 51% (95%CI: 42-61%) respectively (figure 1). The 10-year cumulative risk of histological transformation was 17% (95%CI: 13-21%), with 5-year post-transformation OS of 42% (32-54%). At the time of transformation, 60% were chemo-naive and 52% had never been treated for SMZL. The 5-year OS for chemo-naive patients with transformation was 54% (95%CI: 41-71%) versus 24% (95% CI: 13-44%) for transformations after (immuno)chemotherapy (p = 0.01). When comparing patients intended for treatment in first line with splenectomy (n=312) versus rituximab (n=70), patients treated with splenectomy more frequently presented with extra-hilar lymphadenopathy (35% vs 18%), splenomegaly (92% vs 87%) and anemia (64% vs 48%). OS was similar for the two groups (Figure 2, p = 0.53). The 5-year EFS were 63% (95%CI: 57-68%) and 64% (95%CI: 54-77%), respectively (p = 0.31). Conclusions: To date, this is the largest real-world study of SMZL with detailed treatment and outcome data. The study shows that histological transformation was not uncommon with 10-year risk of 17%. However, outcomes for the entire cohort were excellent irrespective of initial treatment and both OS and EFS were similar after first line rituximab versus splenectomy. Long-term survival remained relatively high even following multiple lines of therapy.
Autologous Stem Cell Transplant in Fit Patients with Late Relapsed Diffuse Large B-Cell Lymphoma That Responded to Salvage Chemotherapy

Blood | December 1, 2023 | Volume: 142 | Issue: Supplement 1 | Pages: 2216-2216

10.1182/blood-2023-185002

Background: The new standard of care for fit patients with refractory or early relapse of diffuse large B-cell lymphoma (DLBCL) is chimeric antigen receptor T-cell (CAR-T) therapy. However, for patients with a relapse ≥12 months after completing frontline therapy, salvage chemotherapy followed by high-dose chemotherapy and autologous stem cell transplant (ASCT) remains the standard of care. There is a need to characterize such patients and their survival in view of the recent shift in treatment paradigm. Methods: Patients with DLBCL that relapsed ≥12 months after R-CHOP or R-CHOP-like frontline therapy who underwent salvage therapy and ASCT at Mayo Clinic or University of Iowa between 07/2000 and 4/2020 were identified from institutional lymphoma and transplant databases. Clinical characteristics, treatment information, and outcome data were abstracted. Progression-free survival (PFS) and overall survival (OS) from the time of ASCT were analyzed using Kaplan-Meier method and Cox proportional hazards models. Statistical analyses were performed in JMP v15. Results: A total of 158 patients with late relapsed DLBCL who underwent salvage chemotherapy and ASCT were identified. Baseline characteristics at relapse/ASCT are shown in Table 1. Median time from frontline therapy completion to 1st relapse was 26.4 months (range 12.0-152.4). Median age at relapse was 63 years (range 19-77), and 96 (61%) patients were male. A minority (3; 3%) had ECOG PS ≥2. 43 (52%) patients had an elevated serum LDH level, 70 (65%) had advanced stage disease, and 12 (11%) had >1 extranodal involvement. Median line of salvage therapy was 1 (range 1-3), and 17 (11%) patients required >1 line of salvage therapy. Best response before ASCT was complete response (CR) in 97 (61%) and partial response (PR) in 61 (39%). Median age at ASCT was 64 years (range 19-78). Median follow-up after ASCT was 91.5 months (95% CI 74.0-103.3). Median PFS and OS were 54.5 (95% CI 31.9-77.8) and 99.8 (95% CI 60.3-144.5) months, respectively. The 2-year PFS and OS rates were 64% (95% CI 56-71) and 81% (95% CI 74-87), respectively. No statistically significant difference in PFS was seen based on age at ASCT, sex, serum LDH, stage, or extranodal site involvement of >1 at relapse (Table 2). However, patients who required > 1 line of salvage therapy, compared to those requiring 1 line of salvage therapy, had significantly inferior PFS (median 6.1 vs 61.8 months, P <0.0001) and OS (17.8 vs 111.7 months, P <0.0004). There was no statistically significant difference in survival in patients who achieved CR vs PR prior to ASCT, with a median PFS of 61.8 vs 37.8 months( P=0.21) and a median OS of 111.7 vs 78.3 months ( P=0.62). Patients who achieved CR after 1 line of salvage therapy had the most favorable PFS and OS, with a median PFS of 65.6 vs 45.4 vs 6.1 vs 7.6 months ( P=0.0004) and a median OS of 133.0 vs 88.9 vs 24.2 vs 17.6 months ( P=0.004) in patients achieving CR after 1 line of salvage therapy vs PR after 1 line of salvage therapy vs CR after >1 line of salvage therapy vs PR after >1 line of salvage therapy, respectively (Table 2). In multivariate Cox regression models adjusted for age at ASCT and sex, patients requiring > 1 line of salvage therapy, compared to those who required 1 line of salvage therapy, had significantly inferior PFS with a hazard ratio (HR) of 3.25 (95% CI 1.82-5.78, P <0.0001) and OS with a HR of 3.50 (95% CI 1.86-6.60, P=0.0001). However, there remained no significant difference in survival based on response status (CR vs PR) with a HR for PFS 0.78 (95% CI 0.52-1.17, P=0.23) and OS 0.93 (95% CI 0.58-1.47, P=0.74). Conclusions: Survival after ASCT was excellent in patients with late relapsed DLBCL achieving CR after 1 line of salvage chemotherapy. Favorable survival outcomes were seen in patients who achieved PR after 1 line of salvage therapy. These data support the current clinical practice of ASCT consolidation in these patients. However, post-ASCT survival was poor in patients who required more than 1 line of salvage chemotherapy, despite achieving a satisfactory response to subsequent lines of salvage therapy. Alternative treatment strategies such as CAR-T therapy should be considered in such patients.
A National Cancer Database Study of Survival Trends in Patients with Mantle Cell Lymphoma Stratified By Age Group

Blood | December 1, 2023 | Volume: 142 | Issue: Supplement 1 | Pages: 1663-1663

10.1182/blood-2023-179611

Background The therapeutic landscape of mantle cell lymphoma (MCL) has evolved significantly since the early 2000s. We previously reported that a shift in frontline immunochemotherapy choices from 2002−2009 to 2010−2015 was associated with improved event-free survival and overall survival (OS) in both younger (age ≤65) and older (age >65) patients in a prospective Mayo Clinic/University of Iowa cohort (Castellino, Blood Advances, 2022). In addition, we recently reported that changes in treatment for relapsed/refractory (R/R) disease over the last two decades were associated with steady improvements in OS for R/R MCL (Tawfiq, ASH, 2022). In this study, we utilized data from the National Cancer Database (NCDB) to investigate the impact of therapy in the modern era on survival outcomes of patients with MCL in the US since 2004. Methods The NCDB is an outcomes database of more than 1,500 hospital-based cancer registries covering approximately 70% of newly diagnosed cancers in the US. The latest version of NCDB was used to identify patients with newly diagnosed MCL from 2004 to 2020. Three treatment eras were defined as Era 1 (2004−2009), Era 2 (2010−2014), and Era 3 (2015−2020), based on immunochemotherapy changes (from Era 1 to Era 2) and increased access to novel agents such as Bruton's tyrosine kinase (BTK) inhibitors (from Era 2 to Era 3). Overall survival between different eras was stratified and analyzed based on 3 age groups: <65, 65−79, and ≥80 years. Survival analysis was performed using the Kaplan-Meier method and all Cox proportional hazards models were adjusted for age and sex. Results A total of 32,746 patients with newly diagnosed MCL was identified, 12,847 (39.2%) patients were age <65, 14,297 (43.7%) age 65−79, and 5,602 (17.1%) age ≥80. For every age group, the distributions in sex, stage, Charlson-Deyo score, and treatment facility type (academic vs non-academic) were largely similar between eras. As expected, the median OS was significantly worse for patients age ≥80 years (19.8 months) compared to patients age 65-79 years (60.9 months) and patients age <65 years (143.9 months; p <0.001). In patients age <65 years, OS in Era 2 was improved when compared to Era 1, with a 5-year OS rate of 72.1% vs 67.6% (logrank p<0.001) (Figure 1) and an age- and sex-adjusted hazard ratio (HR) of 0.83 (95% CI 0.78−0.89, p<0.001). OS in Era 3 was similar to that in Era 2, with a 5-year OS rate of 72.2% vs 72.1% (logrank p=0.61) and an age- and sex-adjusted HR of 0.97 (95% CI 0.89−1.06, p=0.51). In patients age 65-79 years, similar trends in OS changes between eras were observed. The 5-year OS rate in Era 1, Era 2, and Era 3 was 43.3%, 52.8%, and 54.9%, respectively (p<0.001 comparing Era 2 vs Era 1, and p=0.05 comparing Era 3 vs Era 2). Age- and sex-adjusted HR was 0.83 (95% CI 0.78−0.87, p<0.001) comparing Era 2 vs Era 1 and 0.95 (95% CI 0.89−1.01, p=0.07) comparing Era 3 vs Era 2. In patients age ≥80 years, the improvement in OS from Era 1 to Era 2 was less prominent than other age groups. The 5-year OS rate was 22.9% vs 19.5% (p=0.03), and age- and sex-adjusted HR was 0.88 (95% CI 0.81−0.94, p<0.001). OS in Era 3 vs Era 2 was similar, with a 5-year OS rate of 23.1% vs 22.9% (logrank p=0.79) and an age- and sex-adjusted HR of 0.98 (95% CI 0.91−1.06, p=0.67). Conclusions This large NCDB study demonstrated that survival of patients with newly diagnosed MCL has improved over the last two decades. The results are consistent with our Mayo Clinic/University of Iowa prospective cohort study and confirm an improved OS after 2010, which was most likely driven by both frontline immunochemotherapy changes and better access to novel agents for R/R disease. The 5-year OS in patients diagnosed in 2015−2020 did not appear to be superior to those in 2010−2014, despite presumably having better access to novel agents such as BTK inhibitors in the R/R setting. This lack of a difference in OS may be partially due to short follow-up, but may also suggest that further improvement in frontline therapies by incorporating novel agents may be required to improve OS. The OS of patients age ≥80 years is limited and has only minimally improved after 2010, highlighting a significant unmet need for therapies with improved tolerability and efficacy in this age group.
Impact of Frontline Treatment Strategy on Quality of Life in the First Decade after a Diagnosis of Marginal Zone Lymphoma

Blood | December 1, 2023 | Volume: 142 | Issue: Supplement 1 | Pages: 2394-2394

10.1182/blood-2023-186862

Background: Marginal Zone Lymphoma (MZL) is considered indolent but incurable, with a variety of initial treatment strategies including observation. Quality of life (QOL) can be affected by disease burden, side effects of treatment, and psychosocial effects of living with an incurable cancer. However, little is known about long-term QOL in patients with MZL. We investigated QOL at baseline (BL), and up to nine years after a diagnosis of MZL. Methods: Newly diagnosed MZL patients aged 18 years and older were prospectively enrolled within 9 months of diagnosis in the Iowa/Mayo Clinic Molecular Epidemiology Resource from 9/2002 - 6/2015. Pathology was reviewed by a hematopathologist. All MZL participants with both BL and at least one follow-up (FU) QOL questionnaire were eligible for this analysis. QOL was measured at BL and years 1-, 2-, 3-, 6- and 9-year FU with the Functional Assessment of Cancer Therapy-General (FACT-G) scale (range 0-108), which measures 4 QOL domains (range): physical (0-28), social/family (0-28), emotional (0-24), and functional (0-28) well-being (WB). Clinical data were abstracted according to a standard protocol and patients were systematically followed for events (progression, re-treatment, and death). Patients were grouped into initial management with active surveillance (observation), local/antibiotic therapy (including radiation, surgery, and anti- H. pylori therapy), or systemic therapy (including chemotherapy, targeted agents, or antibody therapy). Change in QOL scores over time was analyzed using mixed models for repeated measurements, and comparisons were made according to initial treatment group. Results: Of 324 participants in the analysis, 59% were female, 98% were White and the median age was 63 years. For initial management, 36% (N=118) were observed, 30% (N=96) received local/antibiotic therapy and 34% (N=110) received systemic therapy. Across the initial treatment groups, there were no statistically significant differences by age, gender, or performance status, while there were differences for Ann Arbor Stage IV (observation 50%, local/antibiotic 27%, systemic 67%, p<0.001) and MALT-IPI score 2+ (observation 23%, local/antibiotic 18%, systemic 28%, p<0.001). At BL, mean FACT-G total score was 85.7 (SD 13.1), and physical, social/family, emotional, and functional WB scores were 20.3 (SD 4.2), 24.4 (SD 3.9), 18.9 (SD 3.5), 22.1 (SD 5.3); these scores were similar across initial treatment groups (all p>0.05). FACT-G total score was largely stable over time by treatment group (Panel 1). However, it declined at years 6 (mean -4.0, p<0.05) and 9 (mean -3.7, p<0.05) in the observation group (Panel 2), driven by a decline in functional WB, although this change was not significantly different from the other treatment groups. Further, in comparison with other treatment groups, local therapy was associated with a short-term 1-year improvement of FACT-G total score (mean +2.8, p=0.04), driven by improvements in both functional and emotional WB. For the subscales, we identified two major trends irrespective of treatment group: an overall improvement from BL of emotional WB at years 1 (mean +0.6, p<0.05), 2 (mean +0.7, p<0.05), 3 (+1.3, p<0.05), 6 (+1, p<0.05), and 9 (+1.3, p<0.05) and an overall decline of social/family WB at years 1 (mean -1.1, p<0.05), 2 (mean -1.7, p<0.05), 3 (-2.1, p<0.05), 6 (-2.7, p<0.05), and 9 (-2.2, p<0.05). There was no notable change from BL for physical or functional WB. Conclusions: This analysis is the first to provide prospective real-world QOL data on a longitudinal cohort of MZL patients with long follow-up. At BL, initial treatment was associated with stage and MALT-IPI score, but not QOL. Except for the transient 1-year QOL improvement in patients under local/antibiotic therapy, initial treatment groups had no impact on QOL over time. Irrespective of treatment group, emotional WB showed improvement over time, suggesting psychosocial adaptation by the patient, as it was found in aggressive lymphomas (Thompson et al., 2018). Further, emotional WB over time did not vary across treatment groups, suggesting that being initially observed did not lead to more emotional stress than being actively treated. Finally, decline in social/family WB (support from friends, family, family acceptance of illness, family communication, close to partner) suggests a need to consider interventions to patients and families to address these needs.
LEO Consortium for Real World Evidence (CReWE): Outcomes after Second-Line Therapy in Large B-Cell Lymphoma By Treatment Era

Blood | December 1, 2023 | Volume: 142 | Issue: Supplement 1 | Pages: 307-307

10.1182/blood-2023-186270

Background: Recently, large B-cell lymphomas (LBCLs) have undergone major shifts in classification and treatment paradigm, particularly with the advent of CD19-targeted chimeric antigen receptor T cell therapy (CAR-T). Initially approved as third-line treatment in LBCL in 2017, as of early 2022 CAR-T is indicated for second-line therapy (2L) in patients with relapsed or refractory (R/R) disease within 12 months of frontline treatment or who are not candidates for autologous stem cell transplant (ASCT). Given this quickly changing landscape, we aimed to describe disease characteristics, patterns of care, and survival outcomes in patients with R/R LBCL receiving two or more lines of systemic therapy across modern treatment eras. Methods: We developed a database of patients with R/R LBCL from 8 U.S. academic centers in the Lymphoma Epidemiology of Outcomes (LEO) Cohort study (NCT02736357) and Consortium for Real World Evidence (CReWE). Unlike the SCHOLAR-1 dataset (M Crump et al, Blood 2017), our cohort included any patient receiving 2L, regardless of timing of progression/relapse. For this analysis, eligible patients were aged ≥18 years and received 2L between 2002-2022. Patients with histologic transformation, post-transplant lymphoproliferative disorder, primary CNS lymphoma, primary mediastinal B-cell lymphoma, Burkitt lymphoma, or plasmablastic lymphoma were excluded. Prognostic factors, therapy details (including intent for ASCT and/or CAR-T), and outcomes, including treatment response, event-free survival (EFS), and overall survival (OS), were abstracted for all lines of therapy. Treatment eras were defined as pre-CAR-T (2002-2010), CAR-T available via clinical trial (2011-2017), and post-FDA approval of CAR-T (2018-2022). Results: Of 1760 patients initiating 2L for R/R disease, 1523 were eligible for analysis. Median age at start of 2L was 62 (interquartile range [IQR] 53-70), and 65% were male; 11% were non-White, and 8% were Hispanic. High-grade subtypes comprised 16% of all cases. IPI was available for 1013 patients at time of 2L therapy, with 54% having IPI 3-5. Median time from diagnosis to 2L was 8.7 months (IQR 5.6-18.5), with 834 patients not having achieved complete response (CR) to 1L, 285 patients relapsing <12 months after 1L, and 404 patients relapsing ≥12 months after 1L. The median number of total lines of therapy received was 4 (range 2-18), with 586 and 347 receiving ASCT and CAR-T, respectively, at any line of treatment. At a median follow-up of 48 months from the start of 2L, 926 patients (61%) had died. Progressive lymphoma was the primary cause of death in 75% of deceased patients, with 8% of reported deaths due to therapy. 2L was received at an academic medical center in 83% cases, and 209 patients (14%) received 2L on a clinical trial. ASCT and/or CAR-T was planned at 2L for 989 patients (65%), of whom 463 ultimately received ASCT, 88 received CAR-T, and 21 received allogeneic transplant at 2L. 494 patients were not considered for ASCT or CAR-T at 2L, and 40 were unknown for ASCT/CAR-T intent. Breakdown by treatment era (n = 1518 with available treatment start date) is shown in the Table. Median EFS from start of 2L was 4.2 months (95% confidence interval [CI]: 3.8-4.8). Median OS from start of 2L was 18 months (95% CI: 17-22), and 2- and 5-year OS estimates were 46% (95% CI: 44-49%) and 35% (95% CI: 33-38%), respectively. EFS and OS improved significantly for patients initiating 2L between 2011-2017 compared to 2002-2010. However, EFS and OS in the 2018-2022 era remained similar to 2011-2017 (Figure). Conclusions: To our knowledge, this study is the first-ever large-scale attempt to describe patterns of care and outcomes in LBCL 2L in the modern era, inclusive of all treatment approaches. The rich and unique LEO CReWE dataset captures evolving practice approaches over time in terms of both intent for and receipt of cellular therapies. Likely reflecting the rapid development of many novel immune effector cell products and bispecific antibodies, we observed increased enrollment on 2L clinical trials in the 2018-2022 period, including a substantial proportion of patients receiving CAR-T in 2L. Importantly, survival increased in treatment eras during which CAR-T was available. Ongoing analyses of factors associated with improved survival will be presented at the meeting.
The FLIPI24 Prognostic Model Identifies Poor Outcomes in Non-Immunochemotherapy Treated Patients with Follicular Lymphoma

Blood | December 1, 2023 | Volume: 142 | Issue: Supplement 1 | Pages: 1657-1657

10.1182/blood-2023-186684

Background: We previously reported thatearly events in follicular lymphoma (FL), defined as progression of disease within 24 months (POD24) or early transformation to a more aggressive histology, are significantly associated with increased risk of lymphoma related death. To refine clinical management, the FLIPI24 prognostic model was developed to predict the risk of early events after starting immunochemotherapy (IC) (Maurer et al, 2022). The FLIPI24 model was found to be significantly superior to standard clinical models for prediction of both event-free survival at 24 months (EFS24) and overall survival (OS) in internal and external validation sets of patients receiving IC. We sought to evaluate the prognostic ability of the FLIPI24 model in patients with FL not receiving IC. Methods: The cohort consists of prospectively enrolled patients in the University of Iowa/Mayo Clinic SPORE Molecular Epidemiology Resource (MER) and the multicenter Lymphoma Epidemiology of Outcomes (LEO) Cohorts. Data were collected from medical records by standard protocol with all events verified by medical record review. Eligible patients were those diagnosed with grades 1-3A FL and initiated observation, rituximab monotherapy, radiation, or other non-IC therapy. The FLIPI24 model utilizes 5 continuous variables: age (linear 60-90 years with inflection at age 75), HGB (linear 8-17 g/dL), WBC (linear 4-11x10 9/L), LDH/ULN (linear 0.5-5), and B2M (linear 1-10 mg/L). FLIPI24 risk is grouped as follows: low risk (≤10%], low-average risk (10-15%], average risk (15-20%], high risk (20-40%], very high risk (>40%) for an early event. EFS was defined as time from diagnosis to progression, relapse, (re)treatment, histologic transformation, or death due to any cause. OS was defined as the time from diagnosis until death from any cause. Cox models and Kaplan Meier curves were used to evaluate association between FLIPI24 and EFS or OS. Results: 1542 patients initiating non-IC management approaches at diagnosis from 2002-2020 were identified. 51% were >60 years (IQR 52-70), and 49% were male. Most patients (86%) had FL grade 1-2. 61% of patients met any criteria for high tumor burden per GELF, BLNI, or GITMO based on available variables. Treatment approaches were 833 observation (54%), 315 rituximab monotherapy (20%), 186 radiation (12%), and 208 other non-IC approaches (14%). At median follow-up of 58 months, EFS24 was 73.8% (95% CI: 71.6%, 76.1%), 5-year OS was 90.9% (95% CI: 89.3%, 92.5%) and 253 (16%) patients died. The FLIPI24 score identified poor outcomes among patients with high/very high-risk score (FLIPI24 >20%), with median EFS of 1.8 years (95% CI, 1.3, 3.28) and 5 year OS of 65.1% (95% CI: 55.9-75.8) (Figure 1). When evaluating patient subsets, for patients with high tumor burden (defined based on available variables) and high/very high-risk score, median EFS was 1.6 years and 5 year OS was 64.6% (95% CI: 54.9%-76.1%). Among patients with low tumor burden FL and high/very high-risk score, median EFS was 2.0 years (95% CI: 0.84-NA) and 5 year OS was 66.2% (95% CI: 42.4%-100%). Patients undergoing observation with high/very high-risk score similarly had shortened median EFS of 1.53 years (95% CI: 1.25-NA) and 5 year OS of 68.9% (95% CI: 56.4%-84.1%). The FLIPI24 had superior concordance for OS (c=0.726) compared to the FLIPI (c=0.646) when evaluated in patients not treated with IC. Results were comparable in the subsets of patients observed (c=0.706 vs 0.596) and receiving rituximab monotherapy (c=0.764 vs 0.721). Conclusion: The FLIPI24 model has been previously validated to provide an individual risk score at diagnosis for the likelihood of experiencing an event within 24 months from starting IC. Here we demonstrate that a high FLIPI24 score predicts for poorer outcomes following non-IC strategies including observation, treatment with radiation, and rituximab monotherapy. The FLIPI24 has better prognostic performance for OS than FLIPI in this non-IC population. High FLIPI24 in patients not treated with IC identifies a patient population who should be considered for IC and/or novel frontline therapies when feasible.
Treatment Pattern and Survival Outcome of Limited Stage Mantle Cell Lymphoma: A National Cancer Database Analysis in Pre-BTK Inhibitor Vs BTK Inhibitor Era

Blood | December 1, 2023 | Volume: 142 | Issue: Supplement 1 | Pages: 1666-1666

10.1182/blood-2023-177790

Background Limited stage (stage I−II) disease is an uncommon presentation of mantle cell lymphoma (MCL), and its optimal management remains controversial. A British Columbia study (Leitch, Ann Oncol, 2003) and a Surveillance, Epidemiology and End Results (SEER) study (Murthy, Clin Lymphoma Myeloma Leuk, 2014) suggested the importance of radiotherapy (RT). A National Cancer Database (NCDB) study in the pre-BTK inhibitor (BTKi) era showed that chemotherapy (Chemo) plus RT (Chemo+RT) improved overall survival (OS) compared to Chemo or RT alone (Gill, Int J Radiat Oncol Biol Phys, 2015). However, a retrospective International Lymphoma Radiation Oncology Group study (Dabaja, Ann Oncol, 2017) reported comparable OS with Chemo+RT vs Chemo or RT alone. The potential differences in OS with different frontline therapy modalities may be modified by subsequent therapies for relapsed or refractory (R/R) disease. In this study, we used the NCDB data to analyze frontline treatment patterns and outcomes of limited stage MCL in the pre-BTKi vs BTKi eras. Methods The NCDB was queried to identify patients with stage I−II MCL diagnosed in 2004−2020. Because the first BTKi ibrutinib was approved by the FDA for R/R MCL in November 2013, we defined 2004−2013 as pre-BTKi era and 2014−2020 as BTKi era. Frontline treatment modalities were categorized to RT alone, Chemo alone, or Chemo+RT. Survival analysis was performed using the Kaplan-Meier method and the Cox proportional hazards model. Results Among 32,746 patients with newly diagnosed MCL in 2004−2020, 3,836 (11.7%) presented with stage I−II disease, with 2,428 having treatment information available. For patients diagnosed in the pre-BTKi era (n = 2005), 195 (9.7%) received RT alone, 1472 (73.4%) received Chemo alone, and 338 (16.9%) received Chemo+RT. For patients diagnosed in the BTKi era (n = 423), 45 (10.6%) received RT alone, 320 (75.7%) received Chemo alone, and 58 (13.7%) received Chemo+RT. Patients in the RT alone group were older (P <0.001) and had more females (P <0.001), but there were no statistically significant differences in Charlson-Deyo score, international prognostic index, or treating facility type (academic vs non-academic). For patients with stage I disease, in the pre-BTKi era, patients treated with Chemo+RT (n = 182) had improved OS compared to those treated with RT alone (n = 141) or Chemo alone (n = 647), with a 5-year OS of 75.4% vs 71.8% vs 61.4% (P <0.001). Similar results were observed in the BTKi-era, with a 5-year OS of 83.6% vs 69.5% vs 62.9% (P <0.001) for patients treated with Chemo+RT (n = 31), RT alone (n = 30), or Chemo alone (n = 130), respectively. After adjusting for age and sex, Chemo+RT was associated with improved OS compared to Chemo alone (pre-BTKi era, HR = 0.59, 95% CI = 0.46−0.75, P <0.001; BTKi era, HR = 0.34, 95% CI = 0.14−0.79, P = 0.013), but not compared to RT alone (pre-BTKi era, HR = 0.62, 95% CI = 0.23−1.68, P = 0.343; BTKi era, HR = 0.77, 95% CI = 0.56−1.05, P = 0.10) (Figure 1A). For patients with stage II disease, in the pre-BTKi era, patients treated with Chemo+RT (n = 156) had improved OS compared to those treated with RT alone (n = 54) or Chemo alone (n = 825), with a 5-year OS of 70.0% vs 47.3% vs 58.4% (P <0.001). In the BTKi-era, patients treated with Chemo+RT (n = 27) or RT alone (n = 15) both had improved OS compared to those treated with Chemo alone (n = 190), with a 5-year OS of 77.2% vs 78.8% vs 61.9% (P = 0.004) . After adjusting for age and sex, Chemo+RT was associated with improved OS compared to Chemo alone in BTKi era only (pre-BTKi era, HR = 0.85, 95% CI = 0.67−1.07, P = 0.165; BTKi era, HR = 0.49, 95% CI = 0.25−0.95, P = 0.034), but not compared to RT alone (pre-BTKi era, HR = 0.78, 95% CI = 0.53−1.13, P = 0.185; BTKi era, HR = 0.97, 95% CI = 0.35−2.67, P = 0.952) (Figure 1B). Conclusions Treatment pattern for limited stage MCL has not changed significantly from the pre-BTKi era to the BTKi era, with approximately 15% of patients receiving Chemo+RT, 10% RT alone and 75% Chemo alone. In the BTKi era, Chemo+RT appeared to be associated with better OS compared to Chemo alone but not compared to RT alone. Interpretation of the results requires caution because (1) patient numbers are small in Chemo+RT and RT alone groups, (2) longer follow-up may be needed, and (3) selection of therapy was not random, eg, patients receiving Chemo alone may have had higher disease burden such as bulky disease and/or non-contiguous stage II involvement but these details are not available in NCDB.
DEK Regulates B-Cell Proliferative Capacity and Is Associated with Aggressive Disease in Low-Grade B-Cell Lymphoma

Blood | December 1, 2023 | Volume: 142 | Issue: Supplement 1 | Pages: 4360-4360

10.1182/blood-2023-180232

Introduction: Non-Follicular Low-Grade B-Cell Lymphomas (LGBCL) are a subset of lymphomas that share overlapping clinical and histologic features. While most cases of LGBCL have an indolent course, some experience aggressive disease with no definitive biomarkers to identify aggressive cases at diagnosis. Significant advances have been made in the molecular classification of other lymphomas, yet molecular profiling and identification of mechanisms driving aggressive disease in LGBCL remain an unmet need. We previously used a multi-omic approach to characterize the molecular and immune landscapes of LGBCL tumors and identified a transcriptomic signature associated with cell proliferation and inferior overall survival (OS) in two independent cohorts (HR 7.82; 95% CI 2.4-25.4; p < 0.001 & HR 10.07; 95% CI 2.00-50.61; p = 0.005) and cases that transformed to DLBCL (Hopper et al., 2023). Here, we identify the oncoprotein DEK as a novel transcriptional regulator of this signature and use a functional genomic approach to further interrogate the role of DEK in B-cell lymphoma. Methods: Tumors from 64 newly-diagnosed/untreated LGBCL cases enrolled in the University of Iowa/Mayo Clinic Molecular Epidemiology Resource were included in this study (SMZL = 48, NMZL = 6, LPL = 5, B-NOS = 3, EMZL = 2). Tumor RNA-seq and paired tumor-normal WES were used to assess DEK expression and identify copy number alterations (CNAs), respectively. DEK deficient (KO) cell line models were generated using CRIPSR/Cas9. DEK expression was assessed by western blot (WB) and immunofluorescence (IF) using standard techniques. Proliferation was assessed by MTT assay. Results: To identify transcriptional regulators of our previously identified signature, we used the tool MAGIC to mine publicly available ChIP-seq data and identified DEK, an oncoprotein associated with tumorigenesis and poor prognosis in several cancers, as a key regulator of genes in our signature (p = 0.008). RNA-seq indicated that high levels of DEK expression associated with inferior OS in LGBCL (HR 2.99; 95% CI 1.21-7.36; p = 0.02). Additionally, we identified DEK as a target of copy number gains/amps in LGBCL (7% of cases), which corresponded to significantly higher DEK expression (p = 0.04). The association of DEK with aggressive lymphoma was confirmed when we assessed its expression in public cell line RNA-seq data and observed the highest expression in lines derived from aggressive lymphomas, which we further validated at the protein level in a panel of B-cell lymphoma cell lines by WB and IF confocal microscopy. Additionally, we detected nuclear localization of DEK, consistent with its role as a transcriptional regulator. As a model of DEK overexpression for functional characterization, we used the SUDHL6 lymphoma cell line, which has an amplification of DEK at 6p22.3 and expresses high levels of DEK protein. Using CRISPR technology, we generated DEK deficient SUDHL6 and tested the impact of loss of DEK expression. DEK KO cells proliferated significantly slower than WT SUDHL6 cells in vitro (p < 0.0001)(Panel A), indicating DEK plays a role in regulating proliferative capacity in lymphoma. To identify mechanisms responsible for reduced proliferation in DEK KOs, we assessed baseline protein expression levels of apoptosis proteins in WT versus KO cells. We found near complete abrogation of anti-apoptotic protein Bcl-2 and reduction of Bcl-xL expression in DEK KO cells (Panel B). These results indicate DEK may contribute to tumor proliferative capacity by regulating susceptibility to apoptosis. Conclusion: DEK has been implicated in regulation of gene expression, but its precise role has remained elusive, with little known about its role in lymphoma. Using an integrative molecular and functional genomics approach, we identified DEK as a novel oncoprotein in LGBCL that is upregulated in cases with inferior clinical outcome and is regulated by copy number gains/amps. DEK plays a role in regulating tumor proliferative capacity by altering susceptibility to apoptosis through regulation of Bcl-2 and Bcl-xL. Collectively, this data suggests high-risk LGBCL tumors may enrich for cells with DEK overexpression or CNAs as a mechanism driving oncogene addiction, highlighting DEK, and its downstream targets, as potential therapeutic targets in a subset of high-risk LGBCL.
Molecular Classification of Relapsed DLBCL Reveals Novel Biologic Subgroups

Blood | December 1, 2023 | Volume: 142 | Issue: Supplement 1 | Pages: 2770-2770

10.1182/blood-2023-180949

Background Diffuse large B cell lymphoma (DLBCL) is the most common aggressive lymphoid malignancy in adults. Though standard immunochemotherapy regimens can result in clinical remission and cure in a majority of patients, approximately 30% of patients are primary treatment resistant or eventually relapse (rrDLBCL), and their prognosis is very poor. Recent molecular classification by large scale genomic and transcriptomic profiling of newly diagnosed DLBCL tumors has resulted in a deeper understanding of disease drivers, however, the molecular heterogeneity of rrDLBCL is yet to be fully explored. Therefore, in this study, we used an unsupervised approach to better define transcriptional and genetic programs in rrDLBCL samples hypothesizing that molecular stratification within this high-risk group may lead to a better understanding of this disease, which remains an unmet need, and a more personalized therapeutic approach. Methods Data used in this study included RNA (n=143) and whole exome (n=126) sequencing data from available FFPE tumor samples at the time of a relapse (any line of treatment, r1-r10 relapse timepoints included in analysis, one per patient), consented to the Molecular Epidemiology Resource (n=61), banked in the Mayo Lymphoma Biobank (n=50), or consented to the CC-122-ST-001 clinical trial (n=32, NCT01421524). Unsupervised clustering was performed on protein coding gene expression values using the non-negative matrix factorization (NMF) approach. NMF was carried out by performing 200 runs on cluster sizes from 2 to 6. Cell of origin (COO) was determined using the method described by Reddy et al. The tumor microenvironment was analyzed using CIBERSORTx and Lymphoma Microenvironment Classification (LME). Genetic classification was done using LymphGen. Results In order to identify unique transcriptional programs in rrDLBCL, we implemented NMF and consensus clustering to define an ideal quantity of stable patient clusters. We identified 4 rrDLBCL patient clusters (rrC1-rrC4) as the most stable solution, based on consensus clustering selection criteria of iterative NMF runs. While relapse timepoint was not associated with individual clusters, we did observe significant differences in tumor characteristics between the clusters. COO classification found that rrC1 and rrC4 were enriched for GCB-DLBCL while rrC3 was enriched for ABC-DLBCL classification (P < .001). To explore the biologic programs in each cluster, we used pathFindR, which leverages protein-protein interaction networks to identify disease related pathways, rrC1 and rrC4 were defined by pathways involved in cell cycle and mismatch repair; oxidative phosphorylation in rrC2; and MAPK and NF-kB in rrC3. Next, LME classification was done to define patterns in the tumor microenvironment and we found a significant difference between groups (P < .001), with rrC2 and rrC4 tumors enriched for a depleted TME, while rrC1 and rrC3 had a more immune rich or inflammatory TME. This was supported by CIBERSORTx analysis identifying significant differences (P > .001) in abundance of CD8 T cells, memory CD4 T cells, and M1 macrophages between clusters, with rrC4 having the lowest abundance. We then explored genetic patterns in each cluster. Gene level mutation enrichment analysis showed BCL7A mutation exclusively in C4 (6/6, P = .03). The clusters were not associated with LymphGen classification. Lastly, our recently published high risk signature classification that is associated with early clinical failure and is characterized by metabolic dysregulation, a depleted TME, T53 alterations, and poor outcome, was significantly different between the groups (P = .03) with enrichment for high-risk cases in rrC4. In summary, we show for the first time that rrDLBCL patients can be classified into four gene expression clusters that are associated with distinct pathway, TME, and genetic programs. These clusters should now be tested to learn if they can help select patients for newer therapies for rrDLBCL such as CAR-T and bispecific antibodies.