Nowakowski, Grzegorz S.

2087 Background: PCNSL is a rare and aggressive form of NHL in the central nervous system or vitreoretinal space. Despite high initial rates of responses to HD-MTX-based induction chemotherapies, most patients relapse in two years. R/R PCNSL is associated with poor prognosis, representing a clear unmet medical need, as there are no currently approved treatments for this disease. IRAK4 kinase activity is required for TLR and IL-1R signaling in a variety of myeloid and lymphoid cell types, including PCNSL. Recruitment of IRAK4 to these receptors and subsequent activation is facilitated by the MyD88 adaptor protein, which is mutated in ~70% of PCNSL. This leads to constitutive activation of the NF-κB signaling pathway, increased inflammation, and tumor growth. Emavusertib is a novel and potent oral inhibitor of IRAK4 and FLT3, which has demonstrated the ability to cross the blood-brain barrier in PCNSL xenografts. In preclinical studies, the combination of emavusertib with ibrutinib overcomes resistance to BTK inhibitors. This combination has an acceptable safety profile across a broad population of R/R NHL patients, including PCNSL. Here we present updated safety and efficacy data for emavusertib in combination with ibrutinib in patients with R/R PCNSL. Methods: The safety, clinical activity, and potential biomarkers of emavusertib in R/R PCNSL are being investigated in the ongoing open-label, Phase 1/2 TakeAim Lymphoma trial (NCT03328078). The eligible patients with R/R PCNSL received emavusertib (100-300 mg BID) in combination with ibrutinib (560 mg QD) in a 21-day cycle until tumor progression or unacceptable toxicity. Results: Here, we present updated data from R/R PCNSL patients with prior ibrutinib exposure who were treated with emavusertib in combination with ibrutinib. The median number of prior lines of anti-cancer therapies was 3 (range: 2-5), all patients were R/R to both frontline therapy and subsequent ibrutinib regimens. Prior responses to ibrutinib based regimens included only 1 CR. Here, we report a higher CR rate when these patients are subsequently treated with emavusertib in combination with ibrutinib.Results revealed no dose-limiting toxicities. Conclusions: Emavusertib in combination with ibrutinib was well tolerated with an acceptable safety profile and promising efficacy in R/R PCNSL patients with previous exposure to ibrutinib (BTKi). Enrollment in this trial is ongoing (NCT03328078). Clinical trial information: NCT03328078 .

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.

Abstract Introduction: Chimeric antigen receptor T-cell (CAR-T) therapy is an established treatment modality for the management of refractory and/or relapsed non-Hodgkin lymphoma (NHL). Despite restrictions on granulocyte colony-stimulating factor (G-CSF) use in registration clinical trials due to potential worsening of cytokine release syndrome (CRS), G-CSF is often prescribed for neutrophil recovery post-CAR-T in clinical practice. We conducted a retrospective study to assess the association between G-CSF use and the safety and efficacy of CAR-T. Methods: Following Institutional Review Board approval, we retrospectively analyzed NHL patients receiving commercial CD19-targeted CAR-T across Mayo Clinic sites (Arizona, Florida, and Minnesota) between October 2017 and May 2023. Demographics, labs, and post CAR-T events were collected. Electronic medical records were reviewed for G-CSF exposure within Day 1 - 100 post-CAR T. Differences by G-CSF status were examined using a Chi-square test and Kruskal Wallis tests. Hazard ratios (HR) and 95% confidence intervals (CI) for overall survival (OS) were calculated using Cox model. Results: Among 270 CAR-T patients; 106 received G-CSF within 30 days and 164 did not. Median age was 56.9 with G-CSF and 58.3 without G-CSF. Most were male (75.2% G-CSF, 62.6% no G-CSF). Diffuse large B cell lymphoma was the predominant NHL subtype (67.0% G-CSF, 65.2% no G-CSF). G-CSF within 30 days was not associated with reduced incidence of neutropenic fever (11.7% G-CSF vs 9.9% no G-CSF, p = 0.6593) or documented infection (22.1% vs 18.3%, p = 0.4439). G-CSF correlated with decreased profound neutropenia duration (ANC < 100 μL, 0 vs 2 days, p < 0.0001) and incidence within 30 days ( 31.7% vs 60.4%, p < 0.0001) as well as incidence of protracted profound neutropenia (> 7 days, 3.8% vs 22.8%, p < 0.0001). G-CSF was associated with a higher incidence of cytopenias between days 30 -100: severe neutropenia (ANC < 500/uL, 28.8% vs 15.2%, p = 0.0075), severe anemia (Hb < 8 g/dL, 21% vs 9.7%, p = 0.0114), and severe thrombocytopenia (Plt < 50 g/L, 35.2% vs 20.9%, p = 0.0099). Logistic regression analysis showed that none of the examined covariates, including prior autologous stem cell transplant, ECOG PS score, and receipt of bridging therapy, were associated with severe neutropenia likelihood. G-CSF was associated with a higher CRS incidence (89.6% vs 79.9%, p = 0.0343), but grade 3 CRS or higher (4.7% vs 3.7%, p = 0.6675) was no different. No difference in complete response rates (66% vs 61.1%, p = 0.4707) or 2-year OS (p = 0.523) was observed between the 2 groups. Conclusion: G-CSF within 30 days was associated with reduced duration and incidence of profound neutropenia without a significant impact on incidence of neutropenic fever or documented infections. There was a signal of association between G-CSF and increased incidence of low-grade CRS and delayed cytopenias (day 30-100) that warrants confirmation in larger studies. Citation Format: Lay She Ng, Claire I. Yee, Radhika Bansal, Mohamed A. Kharfan-Dabaja, Grzegorz S. Nowakowski, Allison C. Rosenthal, Javier Munoz, Januario Castro, Wern Lynn Ng, Hemant S. Murthy, Yi Lin, Matthew R. Buras, Madiha Iqbal, Yucai Wang, Talal Hilal. Impact of G-CSF on safety and efficacy of CAR T-cell therapy in non-Hodgkin lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6327.

The 2023 Precision Oncology Summit was organized by Binaytara foundation in San Francisco on October 7 th and 8 th . The conference’s theme was the advances in precision oncology and future directions to move away from a one-size-fits-all model to improve outcomes. This manuscript outlines the proceedings of the hematology-focused session during the conference.

PURPOSE Limited evidence exists regarding methotrexate (MTX) resumption after patients with lymphoma receive glucarpidase for toxic MTX levels and acute kidney injury (AKI). METHODS This retrospective review included adults with lymphoma treated with glucarpidase after MTX at Mayo Clinic between January 31, 2020, and October 10, 2022. Descriptive statistics summarize patient characteristics and clinical outcomes. RESULTS Of 11 patients treated with glucarpidase after MTX, seven (64%) were rechallenged with MTX. Indications for MTX rechallenge included confirmed CNS disease (n = 6, 86%) and intravascular lymphoma (n = 1, 14%). Compared with the nonrechallenged subgroup, before receiving MTX that required glucarpidase rescue, the rechallenged patients had lower median pretreatment serum creatinine (Scr; 0.7 v 1.2 mg/dL), and none had AKI with previous MTX doses, n = 0 (0%) versus n = 2 (50%). During the MTX dose requiring glucarpidase rescue, the rechallenged group had lower median peak Scr (1.26 v 3.32 mg/dL) and lower incidence of AKI stage III (n = 1 [14%] v n = 3 [75%]), and none of the rechallenged patients required renal replacement therapy (RRT; n = 0 [0%] v n = 1 [25%]). At the first rechallenge after glucarpidase administration, the median MTX dose reduction was 56% (range, 46%-75%), and the lowest used dose when prescribed according to each treatment protocol schedule was 1.5 g/m2. Two (29%) patients experienced AKI (n = 1 stage I, n = 1 stage II) after MTX rechallenge. Zero patients required RRT, and zero required another glucarpidase administration. Six (86%) patients completed all recommended MTX doses. CONCLUSION In selected adults with lymphoma who required glucarpidase for toxic MTX levels after administration of high-dose MTX, resumption of MTX therapy at lower doses is safe. Patients selected for MTX resumption had experienced less severe AKI during the previous cycle compared with those not selected for MTX resumption.

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.

This commentary is a call to action for a concerted commitment and effort to transform clinical trials and enable people with cancer to participate in clinical trials closer to home. Three key strategies are identified to address major barriers: confront challenges with the interpretation of US Food and Drug Administration Form 1572 requirements (Statement of Investigator); broaden acceptance of local laboratories and imaging centers; and invest in the creation of effective, sustainable partnerships between research centers and local providers.

Background Primary mediastinal large B-cell lymphoma (PMBCL) is an uncommon type of non-Hodgkin lymphoma. Clinicopathologic features are distinct from diffuse large B cell lymphoma, but it shares some clinical and biologic features with Nodular sclerosis classic Hodgkin lymphoma. Central nervous system (CNS) relapse appears to be rare in patients with PMBCL, with limited literature reporting a rate of approximately 1.5% to 4%. We examined the incidence of CNS relapse, treatment approaches and survival outcomes in patients with PMBCL. Methods Patients with newly diagnosed PMBCL seen at Mayo Clinic between 2002 and 2022 were identified using the prospective Mayo Clinic Lymphoma Database. Clinical features, treatment details and outcomes were abstracted from the medical record. Cumulative incidence of CNS relapse was analyzed with death as a competing risk. The association of CNS-IPI, systemic treatment, and CNS prophylaxis approach with CNS relapse rate was analyzed using competing risk models and descriptively. Event-free survival (EFS) for the cohort was defined as time from PMBCL diagnosis to first recorded CNS and/or systemic relapse or death from any cause. Overall survival (OS) was defined as time from PMBCL diagnosis (or CNS relapse) to death from any cause. Survival analysis was performed using the Kaplan-Meier method. Results A total of 124 PMBCL cases were identified. The median age at diagnosis was 37 years and 61% were female. The distribution of CNS-IPI was low-risk in 67 (61%), intermediate-risk in 41 (37%), and high-risk in 2 (2%). 64 patients (52%) received R-CHOP and 54 patients (44%) received R-DA-EPOCH as frontline therapy. High-dose methotrexate (HD-MTX) for CNS prophylaxis was administered to 6 patients (5%), 5 with R-CHOP and 1 with R-DA-EPOCH. 16 patients received intrathecal (IT) chemotherapy (methotrexate and/or cytarabine) for CNS prophylaxis, 3 with R-CHOP and 13 with R-DA-EPOCH. The median follow-up was 56.0 months. The 5-year EFS rate was 75.1% and the 5-year OS rate was 90.7% for the entire cohort. 20 patients had systemic relapse only and 3 had CNS relapse. The cumulative incidence of CNS relapse was 1.84% (95% CI 0.46%-7.17%) at 2 years and 2.92% (95% CI 0.50%-8.84%) at 5 years (Figure 1). No statistically significant association of CNS-IPI, systemic therapy or CNS prophylaxis regimen with CNS relapse rate was found in competing risk models; however, this analysis was limited by a small event number (n=3). Among the 3 patients with CNS relapse, 1 had high-risk CNS-IPI and 2 had intermediate risk. All 3 patients were treated initially with R-CHOP. Two patients did not receive any CNS prophylaxis and 1 patient received IT CNS prophylaxis. All three patients who had CNS relapse were female. Patient #1 was diagnosed at age 48 and had simultaneous CNS and systemic relapse 6 months later. The patient was treated with HD-MTX, temozolomide and rituximab for CNS relapse, and subsequently received multiple therapies for systemic disease including R-DHAP, R-ICE, and died 17 months after CNS relapse. Patient #2 was diagnosed at age 22 and had CNS relapse after 8.7 months, followed by systemic relapse 2 months later. The patient received HD-MTX, temozolomide and rituximab for CNS relapse, followed by systemic and whole-brain radiation therapy (RT) for both systemic and CNS relapse. Subsequently the patient received salvage chemotherapy, autologous and allogeneic stem cell transplant for systemic relapse. The patient died 26.8 months after CNS relapse. Patient #3 was diagnosed at age 24 and had systemic relapse after 20.7 months, followed by CNS relapse 5.4 months later. The patient received methotrexate and whole-brain RT following CNS relapse and died 1.2 months after CNS relapse. Besides these 3 patients, we identified 6 PMBCL patients with CNS relapse who were diagnosed at other medical centers and subsequently referred to our institution for management of refractory disease. The survival after CNS relapse was poor, with a median OS of 10.4 months (95% CI 5.6-15.2). Conclusion Our study showed that the CNS relapse rate (1.84% at 2 years and 2.92% at 5 years) was overall low in patients with PMBCL, consistent with previous reports. CNS relapse was associated with poor survival despite aggressive treatment approaches. Novel approaches utilizing biological risk factors for CNS relapse, such as circulating tumor DNA, are needed to identify patients with CNS relapse.

Introduction: Molecular classifications have been developed to characterize the heterogeneity of diffuse large B cell lymphoma (DLBCL), with activation of BCL6 and Notch signaling pathways acting as driving pathogenic features in C1/BN2 subtype tumors. Among C1/BN2 defining variants are truncating/inactivating SPEN mutations. SPEN regulates the Notch signaling pathway by initiating formation of a repressive complex that facilitates transcriptional repression of Notch target genes. Our group has identified SPEN mutations enriched in DLBCL cases failing to achieve event-free status at 24 months (EFS24). This contrasted with generally favorable outcomes in C1/BN2 tumors, suggesting a potential high-risk molecular feature with unexplored significance. Presenting an opportunity to expand underlying mechanisms and risk stratification in C1/BN2 tumors, we aimed to use a functional genomic approach, combined with clinical data, to characterize the alternative biology stemming from SPEN truncating mutations. Methods: FFPE tumor biopsies from newly diagnosed DLBCL cases (N=444) enrolled in the Mayo Clinic/Iowa Lymphoma Molecular Epidemiology Resource (MER) program were analyzed by WES (n=404) and RNA-seq (n=321). Biologic and clinical variables were annotated for all cases. CRISPR/Cas9 introduced truncating mutations to the endogenous SPEN locus in OCI-LY3 & SU-DHL-2 ABC-type human cell lines to establish models of SPEN depletion. Functional in vitro analysis utilized standard methods for RNA-seq, cell proliferation, western blot, and flow cytometry. Results: WES identified 29/404 ndDLBCL (7.2%) harboring SPEN mutations; n=17 missense and n=12 nonsense or frameshift insertions/deletions (truncating variants - [trunc]), the later considered as the focal point of our study. Against all cases, SPEN trunc cases displayed enrichment for high-risk factors including non-GCB COO (p=0.06, OR=3.7, 95% CI [0.9, 22.2]) and primary refractory disease (PTR; p=0.02, OR=5.0, 95% CI [1.05, 19.9]), and demonstrated inferior OS (p=0.06, HR=2.2), where a majority of clinical progression events occurred within 12 months of diagnosis. Leveraging RNA-seq, we observed 11 of 11 SPEN trunc cases exhibiting a double-hit negative gene expression signature, 9/11 cases with inflammatory or depleted microenvironment (LME), and 8/11 with a signature associating with intermediate/high risk of EFS24 failure. Applying the LymphGen algorithm, 5/12 SPEN trunc cases received the BN2 classification, observing co-occurring mutations with CD70 (p&lt;0.01, OR=9.68), BRCA2 (p=0.03, OR=5.84), TET2 (p=0.02, OR=4.91), IRF4 (p=0.02, OR=7.27), and PTPRD (p&lt;0.01, OR=8.31) genes, and were mutually exclusive with ARID1A, BCL2, EZH2, FAS, HLA-B, IRF8, and TMEM30A mutations ( Figure 1A). Isolating SPEN trunc against BN2 cases without SPEN variants (n=14), despite similar clustering of non-GCB COO (p=0.7), PTR was exclusively observed in SPEN trunc cases, accompanied again by inferior OS (p=0.07, HR=4.2; Figure 1B). In the OCI-LY3 SPEN depletion model, GSEA analysis from RNA-seq revealed activation of E2F (NES=2.7; p=9.4E-20) and MYC target genes (NES=2.3; p=4.1E-6), while both OCI-LY3 and SU-DHL-2 models featured depletion of antigen presentation genes (NES= -1.8, p=5.7E-4; NES= -2.2, p=3.8E-7, respectively). A decrease of MHC class II proteins (HLA-DR, HLA-DP) was confirmed by flow cytometry in both models (p&lt;0.01). Hypothesizing loss of SPEN enhances reliance on the BCL6-HDAC3 axis featured in BN2 tumors, we treated both SPEN depletion models with a class-I HDAC inhibitor highly selective for HDAC3, BRD-3308, and indeed observed a 1.4 and 2.4-fold increase in sensitivity compared to WT cells (p=0.07, p&lt;0.01, respectively). Significance: We find SPEN trunc mutations in poor acting DLBCL cases with clinical and biologic characteristics that diverge from C1/BN2 biology. The enhanced rate of clinical progression highlights urgency to better characterize these tumors. Our data suggests loss of SPEN regulatory mechanisms may act cooperatively with C1/BN2 biology to facilitate tumor immune evasion and drive progression through Notch-mediated pathways. Importantly, in vitro evidence shows SPEN deficient lymphoma cells are susceptible to targeted therapeutics against dependent pathways, providing rationale for advancing individualized care strategies for affected patients.