Citations

7080 Background: Primary mediastinal large B-cell lymphoma (PMBCL) is an uncommon type of aggressive B-cell non-Hodgkin lymphoma. PMBCL has distinct clinicopathologic features compared to diffuse large B-cell lymphoma but shares some clinical and biologic features with nodular sclerosis classic Hodgkin lymphoma (cHL). Central nervous system (CNS) relapse is exceedingly rare in cHL, therefore one may expect that CNS relapse in PMBCL is also uncommon. Herein, we examined the incidence of CNS relapse in patients with PMBCL. Methods: Patients with newly diagnosed PMBCL seen at Mayo Clinic between 1/2002 and 4/2023 were identified from the Mayo Clinic Lymphoma Database. Clinical features, treatment details and outcomes were abstracted from medical records. The CNS relapse rate was calculated using a competing risk model, with death considered as a competing risk. Results: A total of 154 PMBCL cases were identified. The median age at diagnosis was 38 years (range 18-77) and 60.4% were female. The distribution of CNS-IPI was low-risk in 80 (51.9%) patients, intermediate-risk in 43 (27.9%), and high-risk in 3 (1.9%), and data were missing for 28 patients (18.2%). 78 patients (50.6%) received R-CHOP and 76 patients (49.4%) received R-DA-EPOCH as frontline therapy. High-dose methotrexate (HD-MTX) for CNS prophylaxis was administered to 5 patients (all treated with R-CHOP). 20 patients received intrathecal (IT) chemotherapy (methotrexate and/or cytarabine) for CNS prophylaxis (4 with R-CHOP [1 received HD-MTX too],16 with R-DA-EPOCH). The median follow-up was 39 months (95% CI 28.2-49.8). Only 3 patients had CNS relapse, all associated with systemic relapse (1 concurrent, 1 had CNS relapse 8.8 months after systemic relapse, 1 had CNS relapse 2 months before systemic relapse). The cumulative incidence of CNS relapse for the entire cohort was 1.43% (95% CI 0.3%-4.6%) at 1 year and 2.21% (95% CI 0.6%-5.8%) at both 2 and 5 years. For those who did not receive CNS prophylaxis (n=130), the incidence was 0.86% (95% CI 0.1%-4.3%) at 1 year and 1.82% (95% CI 0.4%-5.8%) at both 2 and 5 years. All 3 patients who experienced CNS relapse had R-CHOP as frontline therapy; two patients did not receive any CNS prophylaxis, while 1 patient received IT CNS prophylaxis. Conclusions: The risk of isolated CNS relapse in PMBCL appears to be very low, even in patients who did not receive CNS prophylaxis. While some patients may experience CNS relapse associated with systemic relapse, the overall incidence was low (1.43% at 1 year and 2.21% at 2 and 5 years). The rarity of isolated CNS relapse in PMBCL suggests that routine CNS prophylaxis may not be necessary as part of initial therapy.

7067 Background: High intensity induction with regimens such asDA-EPOCH-R, CODOX-M/IVAC-R and HyperCVAD are often used for young patients with DHL/THL despite no overall survival (OS) benefit compared to R-CHOP. Reports on the application of CODOX-M/IVAC-R are subject to selection bias as only young fit patients can tolerate it. We aimed to investigate outcomes difference between CODOX-M/IVAC-R and DA-EPOCH-R in patients ≤ 60 years with DHL/THL diagnosed via FISH. Methods: Retrospective review of DHL/THL patients from the Mayo Clinic diagnosed between July15th 2010-October19th 2023 treated with CODOX-M/IVAC-R or DA-EPOCH-R at age of up to 60 years. Event free survival (EFS) was defined as time from diagnosis to progression, relapse, next line of treatment or death from any cause. Results: 113 patients were included; CODOX-M/IVAC-R (N=49) and DA-EPOCH-R (N=64). Patient and disease characteristics are in table. 80% (N=39) achieved CR on end of treatment (EOT) PET CT with CODOX-M/IVAC-R compared to only 58% (N=37) with DA-EPOCH-R. CODOX-M/IVAC-R was associated with superior EFS on univariate (HR=0.54, 95%CI=0.31-0.97) and multivariable analysis adjusted for age, BCL2 vs BCL6 translocation and receipt of consolidation ASCT (aHR=0.53, 95%CI=0.29-0.95), however, there was no significant influence on OS (aHR=0.97, 95%CI=0.50-1.91). At a median follow-up of 5.3 years and 3.3 years for the CODOX-M-IVAC and DA-R-EPOCH group respectively; EFS was superior in the CODOX-M/IVAC-R group having 1, 2 and 5 years EFS of 68.3%, 64.1 and 61.5% respectively compared to 52.4%, 48.9% and 39.5% respectively in the DA-EPOCH-R group (p=0.035). 33%(16/49) of the CODOX-M/IVAC-R patients had R/R disease (No CR on EOT PET CT or relapsed) with a median OS of 10.3 months compared to 33.7 months in the R/R DA EPOCH-R group (54%, 35/64). Number of patients who were able to receive salvage ASCT, CAR T and Allo-SCT were 5, 17 and 4 respectively in the DA EPOCH-R group compared to 1, 6 and 3 patients respectively in the CODOX-M/IVAC-R group. None died of regimen toxicity in both groups. 19% underwent ASCT consolidation after CR with initial induction (11 patients in each group); no OS was noticed however consolidation with ASCT was associated with increased EFS regardless of the induction regimen with best outcomes being in the CODOX-M/IVAC-R group (P=0.0072). Conclusions: Our study showed that young patients with DHL/THL who received CODOX-M/IVAC-R had superior EFS compared to DA-EPOCH-R with no OS benefit. CODOX-M/IVAC-R can spare patients receiving more subsequent therapies. Patients who have R/R disease following CODOX-M/IVAC-R have poor outcomes. [Table: see text]

7050 Background: The management of Richter transformation (RT) of CLL represents an unmet clinical need. We previously reported modest efficacy of pembrolizumab monotherapy in an initial cohort of patients with RT (Ding, et al, Blood 2017). Here we report updated results of this trial, including an expansion cohort and a combination therapy cohort. Methods: Patients with biopsy proven RT to diffuse large B-cell lymphoma were enrolled and treated with single agent pembrolizumab (200 mg IV Q3W). Patients with progressive disease (PD) or stable disease (SD) after 3 months of pembrolizumab monotherapy were allowed to add a B-cell receptor (BCR) kinase inhibitor. The primary end point was overall response rate (ORR). Results: A total of 26 patients with RT were enrolled (9 in initial cohort and 17 in expansion cohort). The median age was 68.5 years. Ten (38%) patients had del(17p) or TP53 mutation. The median number of prior lines of therapy was 3 (range 1-10). Fifteen (58%) patients had received ibrutinib previously (14 of whom had PD on ibrutinib). With pembrolizumab monotherapy (n=26), the ORR was 23.1%, with 2 (7.7%) complete response (CR), 4 (15.4%) partial response (PR), and 7 (26.9%) SD. Of the 6 patients with confirmed CR or PR, responses occurred after a median of 2 cycles of monotherapy. The median duration of response (DOR) was 3.2 months (95% CI 2.8-NA). The median progression-free survival (PFS) was 2.6 months (95% CI 1.6-3.6). Sixteen patients went on to receive a BCR kinase inhibitor (ibrutinib [n=15], idelalisib [n=1]) in combination with pembrolizumab, after SD or PD on pembrolizumab monotherapy. The ORR to combination therapy was 62.5%, with 4 (25.0%) CR and 6 (37.5%) PR. Of the 10 patients with confirmed CR or PR to combination therapy, responses occurred after a median of 4 cycles of therapy. The median DOR was 4.5 months (95% CI 1.6-NA). The median PFS was 7.6 months (95% CI 2.3-13.3). After a median follow-up of 50.4 (95% CI 34.0-56.0) months, the median overall survival (OS) for all 26 patients with RT was 11.6 months (95% CI 7.5-20.1), and the 2-year OS rate was 27%. Treatment-related adverse events (TRAEs) of any grade occurred in 24 (92%) patients, including anemia (54%), thrombocytopenia (58%), neutropenia (54%), leukopenia (35%), lymphopenia (23%), dyspnea (23%), diarrhea (19%), and nausea (23%). Treatment-related grade 3 or above AEs occurred in 21 (81%) patients, including neutropenia (38%), leukopenia (31%), thrombocytopenia (27%), anemia (15%), febrile neutropenia (12%), and lung infection (12%). Conclusions: This expanded analysis confirmed that pembrolizumab has modest single agent activity in RT. Combination therapy with pembrolizumab and a BCR kinase inhibitor is associated with increased efficacy (ORR >60%), similar to other reports. These results support further investigation of immune checkpoint inhibitor-based combination therapy in RT. Clinical trial information: NCT02332980 .

With improved medical treatments, the prognosis for many malignancies has improved, and more patients are presenting for transplant evaluation with a history of treated cancer. Solid organ transplant (SOT) recipients with a prior malignancy are at higher risk of posttransplant recurrence or de novo malignancy, and they may require a cancer surveillance program that is individualized to their specific needs. There is a dearth of literature on optimal surveillance strategies specific to SOT recipients. A working group of transplant physicians and cancer-specific specialists met to provide expert opinion recommendations on optimal cancer surveillance after transplantation for patients with a history of malignancy. Surveillance strategies provided are mainly based on general population recurrence risk data, immunosuppression effects, and limited transplant-specific data and should be considered expert opinion based on current knowledge. Prospective studies of cancer-specific surveillance models in SOT recipients should be supported to inform posttransplant management of this high-risk population.

PURPOSE H. pylori eradication therapy (HPE) can lead to tumor regression in H. pylori–positive (HPP) gastric mucosa-associated lymphoid tissue (MALT) lymphoma. However, some patients do not have detectable H. pylori (HP) infection ( H. pylori–negative [HPN]) and the guidelines differ in their initial approach to HPN patients. The National Comprehensive Cancer Network (NCCN) recommends proceeding to radiation therapy, whereas European Society for Medical Oncology suggests HPE for every patient, even those who are HPN. To address this issue, we evaluated the effectiveness of HPE in limited-stage gastric MALT lymphoma. MATERIALS AND METHODS We retrospectively reviewed patients newly diagnosed with stage IE gastric MALT lymphoma between January 2002 and December 2022. The primary outcome was the complete remission (CR) rate defined as no macroscopic findings of lymphoma and negative gastric biopsy at the follow-up gastric endoscopy. RESULTS Fifty-two patients were reviewed, and HP infection was detected in 19 (36.5%) patients—14 by immunostaining, three by serology, and one each by stool antigen and urea breath test. All 19 HPP and eight of the 33 HPN patients received HPE treatment. The CR rate was 63% (12/19) in HPP patients and 13% (1/8) in HPN patients ( P = .033). After a median follow-up of 89.7 months, only two of the 12 HPP patients achieving CR have relapsed; the one HPN patient who received HPE remains in CR at 12+ months. CONCLUSION For limited-stage HPP gastric MALT lymphoma, HPE is an effective and durable first-line treatment and should be used. For HPN patients, the CR rate with HPE is very low in our experience and is thus in support of the NCCN guideline.

Abstract Patients with large B-cell lymphoma (LBCL) that fail to achieve a complete response (CR) or who relapse early after anthracycline-containing immunochemotherapy (IC) have a poor prognosis and are commonly considered to have “primary refractory disease.” However, different definitions of primary refractory disease are used in the literature and clinical practice. In this study, we examined variation in the time to relapse used to define refractory status and association with survival outcomes in patients with primary refractory LBCL in a single-center prospective cohort with validation in an independent multicenter cohort. Patients with newly diagnosed LBCL were enrolled in the Molecular Epidemiological Resource cohort (MER; N = 949) or the Lymphoma Epidemiology of Outcomes cohort (LEO; N = 2755) from September 2002 to May 2021. Primary refractory LBCL was defined as no response (stable disease [SD]) or progressive disease (PD) during, or by the end of, frontline (1L) IC (primary PD; PPD); partial response at end of treatment (EOT PR); or relapse within 3 to 12 months after achieving CR at EOT to 1L IC (early relapse). In the MER cohort, patients with PPD had inferior overall survival (OS; 2-year OS rate: 15% MER, 31% LEO) when compared with other subgroups considered in defining primary refractory disease, EOT PR (2-year OS rate: 38% MER, 50% LEO) and early relapse (2-year OS rate: 44% MER, 58% LEO). Among patients receiving 1L IC with curative intent, we identified that patients with PPD are the key subgroup with poor outcomes. We propose a definition of primary refractory LBCL as SD or PD during, or by the end of, 1L treatment.

SummaryMultiagent chemoimmunotherapy remains the standard of care treatment for Burkitt lymphoma leading to a cure in the majority of cases. However, frontline treatment regimens are associated with a significant risk of treatment related toxicity especially in elderly and immunocompromised patients. Additionally, prognosis remains dismal in refractory/relapsed Burkitt lymphoma. Thus, novel therapies are required to not only improve outcomes in relapsed/refractory Burkitt lymphoma but also minimize frontline treatment related toxicities. Recurrent genomic changes and signalling pathway alterations that have been implicated in the Burkitt lymphomagenesis include cell cycle dysregulation, cell proliferation, inhibition of apoptosis, epigenetic dysregulation and tonic B‐cell receptor‐phosphatidylinositol 3‐kinase (BCR‐PI3K) signalling. Here, we will discuss novel targeted therapy approaches using small molecule inhibitors that could pave the way to the future treatment landscape based on the understanding of recurrent genomic changes and signalling pathway alterations in the lymphomagenesis of adult Burkitt lymphoma.

Abstract Rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) is considered the standard-of-care for patients with advanced-stage diffuse large B-cell lymphoma (DLBCL), despite findings that patients with nongerminal center B-cell like (non-GCB) have significantly worse outcome with this regimen. We evaluated the prognostic significance of baseline risk factors, including cell of origin (COO) classified by the Hans algorithm, within an alternative chemoimmunotherapy program. At Memorial Sloan Kettering Cancer Center (MSK), 151 patients with DLBCL received sequential R-CHOP induction and (R)-ICE (rituximab, ifosfamide, carboplatin, and etoposide) consolidation. Outcome analysis based on COO was validated with a propensity score–matched cohort treated with R-CHOP from the Mayo Clinic component of the Molecular Epidemiology Resource (MER). Among the patients with GCB (n = 69) and non-GCB (n = 69) at MSK, event-free survival (EFS) of non-GCB was superior to that of GCB (hazard ratio [HR], 0.53; 95% confidence interval [CI], 0.29-0.98). Overall survival (OS) demonstrated an association in the same direction but was not statistically significant (HR, 0.68; 95% CI, 0.33-1.42). Propensity score–matched patients from MSK (n = 108) demonstrated a small attenuation in the HRs for EFS (HR, 0.57; 95% CI, 0.27-1.18) and OS (HR, 0.76; 95% CI, 0.33-1.79) and were no longer statistically significant. In contrast, the matched MER cohort (n = 108) demonstrated an EFS association (HR, 1.17; 95% CI, 0.70-1.95) and OS association (HR, 1.13; 95% CI, 0.64-2.00) in the opposite direction, but were also not statistically significant. R-CHOP induction and (R)-ICE consolidation may overcome the negative prognostic impact of the non-GCB phenotype, per the Hans algorithm, and can be preferentially selected for this population. This trial was registered at www.ClinicalTrials.gov as #NCT00039195 and #NCT00712582.

AbstractTo address the current and long‐term unmet health needs of the growing population of non‐Hodgkin lymphoma (NHL) patients, we established the Lymphoma Epidemiology of Outcomes (LEO) cohort study (NCT02736357; https://leocohort.org/). A total of 7735 newly diagnosed patients aged 18 years and older with NHL were prospectively enrolled from 7/1/2015 to 5/31/2020 at 8 academic centers in the United States. The median age at diagnosis was 62 years (range, 18–99). Participants came from 49 US states and included 538 Black/African‐Americans (AA), 822 Hispanics (regardless of race), 3386 women, 716 age <40 years, and 1513 rural residents. At study baseline, we abstracted clinical, pathology, and treatment data; banked serum/plasma (N = 5883, 76.0%) and germline DNA (N = 5465, 70.7%); constructed tissue microarrays for four major NHL subtypes (N = 1189); and collected quality of life (N = 5281, 68.3%) and epidemiologic risk factor (N = 4489, 58.0%) data. Through August 2022, there were 1492 deaths. Compared to population‐based SEER data (2015–2019), LEO participants had a similar distribution of gender, AA race, Hispanic ethnicity, and NHL subtype, while LEO was underrepresented for patients who were Asian and aged 80 years and above. Observed overall survival rates for LEO at 1 and 2 years were similar to population‐based SEER rates for indolent B‐cell (follicular and marginal zone) and T‐cell lymphomas, but were 10%–15% higher than SEER rates for aggressive B‐cell subtypes (diffuse large B‐cell and mantle cell). The LEO cohort is a robust and comprehensive national resource to address the role of clinical, tumor, host genetic, epidemiologic, and other biologic factors in NHL prognosis and survivorship.

Abstract Immune checkpoint inhibitors (ICIs) have demonstrated remarkable response rates in relapsed or refractory Hodgkin lymphoma (HL). Still, most patients eventually progress. Patterns of progression after ICIs are not well described and are essential to defining the role of local therapies in combination with ICIs. We identified patients who received ICIs for HL between 2013 and 2022. Fludeoxyglucose-18 positron emission tomography (FDG-PET) before initiating ICI and at progression on/after ICI were reviewed, and areas of active HL were recorded. An exploratory analysis of treatable progression included patients with ≤5 sites of disease on pre-ICI FDG-PET and progression only at pre-ICI sites. Ninety patients were identified; 69 had complete records, and of these, 32 (52%) had relapsed at ICI initiation, 17 (25%) were refractory, and 16 (23%) received ICI as first-line therapy. Forty-five of 69 patients had ≤5 sites of disease (limited) on pre-ICI FDG-PET. Patients with &gt;5 sites of disease had a higher risk of progression, and every site of disease &gt;5 sites conferred an additional 1.2x higher chance of progression. At a median follow-up of 4.0 years, 41 of 69 patients had progressed on/after ICIs (cumulative incidence 66.4%), and of these, 22 of 41 patients progressed only at pre-ICI sites (cumulative incidence 39.4%). In an exploratory analysis, the cumulative incidence of a treatable progression among 45 patients with limited disease was 34%. The cumulative incidence of any progression among this cohort was 58.9%. More than one-third of patients with limited disease before ICIs experienced progression only at pre-ICI sites of disease. These patients could be candidates for radiation during or after ICIs.