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Background: The BeatAML Master Trial (BAMT) began in 2016 with a goal of determining the feasibility of a precision-medicine approach in treating acute myeloid leukemia (AML) in older adults ≥ 60 years of age where outcomes are poor. At the time, standard of care (SOC) for older patients with AML was intensive 7+3 chemotherapy (cytarabine + daunorubicin) if fit and hypomethylating agents (HMA: azacitidine or decitabine) if unfit. Besides confirming the feasibility, the early results (2019) from the Master Trial suggested that patients who received therapy on one of the sub-studies had a lower early death rate and superior overall survival compared to patients receiving off-protocol SOC, which was primarily single-agent HMA at the time. Since then, the 2019 approval of venetoclax (ven) + azacitidine for older unfit AML patients has been transformative and emerged as the SOC. Using data from the BAMT from 2016-2024, we suggest that knowing the comprehensive genomic profile of AML at the time of diagnosis is still beneficial in determining therapy that would lead to the optimal outcome and that development of targeted therapies and combination regimens with ven/HMA is still needed. Methods: This is a retrospective analysis of 1096 patients who consented and enrolled on the BAMT (NCT03013998) from Nov 2016 through Jun 2024. Patients ≥ 60 years with newly diagnosed AML were included. Patients underwent therapy on a BeatAML sub-study based on their genetics (N=433) or treatment off-protocol (N=663). We divided the patients according to what therapy they received: (1) Non-Intensive (Off-Protocol, N=121), (2) Ven/HMA (Off-Protocol, N=234), (3) Non-Intensive (Sub-Study, N=407), (4) Intensive (Sub-Study, N=26), and (5) Intensive (Off-Protocol, N=155). 94 patients received no treatment and 59 were unknown. Non-intensive therapies included primarily targeted agents or non-ven combinations. We analyzed baseline characteristics and demographics, overall survival (OS), and the impact of allogenic stem cell transplant (SCT). OS, using Kaplan-Meier method, was measured from the start of therapy to all-cause death, censoring patients at last follow-up. Results: Characteristics and demographics were similar between Groups 1, 2 and 3. Group 4 and 5 were treated with intensive chemotherapy and their characteristics are reflective of younger/fit patients appropriate for the intensive regimen. Groups 4 and 5 also had the longest median OS (mOS) of 40.2 months (95% CI: 13.9-not reached (NR)) and 42.3 months (95% CI: 25.1-NR) respectively. Group 3, which included patients treated with a non-intensive, targeted therapy on a sub-study, had an mOS of 14.0 months (95% CI: 12.3-16.7), which was similar to Group 2, treated with Ven/HMA, that had an mOS of 13.2 months (95% CI: 10.9-16.3). Lastly, patients in Group 1, who were treated primarily with HMA monotherapy, did poorly in comparison, with an mOS of 6.0 months (95% CI: 3.3-10.1). Additionally, we looked at the cumulative incidence rate (CIR) of SCT. The CIR in 12 months of Group 1 was 9.8% (95% CI: 6.9-13.4), Group 2: 5.4% (95% CI: 2.2-10.7), Group 3 and 4 combined: 35.0% (95% CI: 628.1-42.1), and Group 5: 13.1% (95% CI: 6.9-13.4). In a multi-variable analysis, after adjusting for typical favorable risk factors like NPM1 mutations and core binding factor, SCT was highly significant (p<0.0001) in improving OS with a hazard ratio of 0.23 (95% CI: 0.16-0.32), and Group 3 performed similarly to Group 2 (p=0.20). Conclusions: First, our results suggest that it is clinically relevant to correctly identify whether an intensive chemotherapy, targeted-therapy, or ven/HMA regimen is best suited for older AML patients, for which a precision-medicine trial is ideal for. Secondly, in this group of patients, our results show that patients treated with a non-intensive targeted therapy (Group 3) has a similar mOS to those treated with ven/HMA (Group 2). Especially after controlling for patient characteristics, patients in Group 2 performed similar to those in Group 3 (p=0.20). Patients in Group 3 were treated on Beat AML sub-studies which included targeted therapy alone or with non-venetoclax combinations, which is a strong rationale for continued development of targeted agents to optimize toxicity and quality of life with similar survival. Lastly, this data also supports the need to improve the ven/HMA SOC by developing combination regimens with targeted agents to further improve outcomes.

Background: Mutations of isocitrate dehydrogenase (IDH) are recurrent in acute myeloid leukemia (AML) and the prevalence increases with age. The prognostic impact of IDH1 and IDH2 mutations remains controversial. IDH inhibitors are small molecules that bind within the IDH enzymatic active site, blocking aberrant 2-hydroxyglutarate production and inducing myeloid differentiation. While they can lead to differentiation syndrome, they generally have a more favorable side-effect profile, making them an attractive option for older patients. We aimed to describe the prevalence and prognostic impact of IDH mutations in newly diagnosed (ND) AML patients ≥ 60 years in a large cohort of patients treated on a Leukemia and Lymphoma Society-sponsored trial. Methods: We performed a retrospective observational analysis including patients ≥ 60 years with ND AML who were enrolled on the Beat AML clinical trial (NCT03013998) before May 10, 2023. Patients were treated with a variety of treatment regimens. Cytogenetic analysis and next-generation sequencing (FoundationOne®Heme) were obtained. Mutations were considered present at any detectable VAF. Cox proportional hazard models were used to describe the relative risk of each variable on death over time from the date of trial inclusion. Results: A total of 1023 patients with ND AML were identified. Patients had a median age of 72 (range 60-92) years and the majority were non-Hispanic White (83.2%), and male (57.6%). Ninety-nine (9.7%) patients were IDH1MUT, 193 (18.9%) patients were IDH2MUT including 10 (1.0%) patients with a co-occurring IDH1 and IDH2 gene mutations. Both IDH1MUT and IDH2MUT were associated with 2022 ELN favorable-risk (26.3% and 22.3% for IDH1 and IDH2 respectively, vs 15.5% overall (P<0.001)). IDH1MUT significantly co-occurred with DNMT3AMUT (42.4%), NPM1MUT (44.4%) and less frequently with TP53MUT (10.1%) (P<0.001 for all). IDH2MUT was associated with DNMT3AMUT (35.8%), NPM1MUT (31.1%), SRSF2MUT (38.3%), and less frequently with TET2MUT (6.7%) and TP53MUT (9.3%) (P<0.001 for all). Normal karyotype was higher in IDH1MUT (P<0.001) and IDH2MUT (P<0.001), whereas complex karyotype (P<0.001 for both) and core-binding factor AML (P=0.047, P=0.015) were lower in IDH1MUT and IDH2MUT. To evaluate the impact of IDH mutations in patients ≥ 60 years, we focused on patients evaluable for outcome treated with lower-intensity therapy (LIT) (N=674), and intensive chemotherapy (IC) (N=178), separately. Among the LIT treated patients, 96 patients received treatment with an IDH inhibitor, and 237 patients received a hypomethylating agent (HMA) plus venetoclax. For patients treated with LIT, the hazard ratios (HRs) of death over time were 0.58 [95% CI 0.47-0.72; P<0.002], 0.81 [95% CI 0.59-1.13; P=0.214] and 0.56 [95% CI 0.44-0.72; P<0.001] for IDHMUT, IDH1MUT, IDH2MUT respectively. Among patients receiving IC, the HRs were 1.05 [95% CI 0.68-1.69; P=0.777], 0.70 [95% CI 0.31-1.61; P=0.406] and 1.27 [95% CI 0.77-2.1; P=0.352] for IDHMUT, IDH1MUT, and IDH2MUT respectively. The HR of death for IDH1MUT patients treated with LIT with the addition of an IDH1 inhibitor (N=24) was significantly lower (HR 0.47 [95% CI 0.24-0.92; P=0.027] vs IDH1MUT patients treated without an IDH1 inhibitor, while an IDH2 inhibitor did not change survivial outcomes in patients with IDH2MUT (N=71). Discussion: To our knowledge this is the largest retrospective study characterizing the prevalence of IDH mutations in patients ≥ 60 years with AML. We demonstrated that IDH mutations were detected in ~27% of older patients with AML. Although there could have been selection bias as the Beat AML study had separate IDHMUT study arms, these findings are concordant with other studies showing an increase in frequency of IDH mutations with age. IDH2MUT was associated with a lower HR of death among patients treated with LIT, which was not seen in patients receiving IC. The high prevalence of IDH mutations suggests that IDH inhibitors used as single agents or in combination with lower-intensity therapies are an important class of drugs for this older patient population as they are generally well tolerated, that need further investigation.

Background Hispanic patients continue to be underrepresented in clinical trials. To better understand the factors that impact clinical trial participation, we surveyed patients with NHL receiving care at an academic institution on their perspectives on clinical trials, barriers to care, and helpful aids to encourage clinical trial participation. Here we report the findings of the Hispanic patients and non-Hispanic white patients; accrual is ongoing for other cohorts of patients. Methods Consecutive patients ≥ 18 years old with histologically confirmed NHL who received care at MD Anderson Cancer Center in the Texas Medical Center in Houston, Texas were invited to participate regardless of treatment status. A self-administered questionnaire was used to assess patient sociodemographic factors, perceptions and willingness to participate in different clinical trial scenarios as well as participant perceived barriers to care and facilitators of trial participation. The questionnaire included a total of 53 items with an additional 13 demographic items. The questionnaire was available in English and Spanish. Results Of the 1204 patients invited, 316 consented to participate and 285 ultimately completed the survey (participation rate 23.7%). Among the total participants, this cohort included 100 self-identified Hispanic (H) participants and 103 non-Hispanic white (NHW) participants diagnosed with NHL who completed the survey and were included here. The histology of our cohort included Follicular Lymphoma (FL) [35.6%]; Diffuse Large B-cell lymphoma (DLBCL) [18.2%], Mantle cell lymphoma (MCL) [18.7%], T-cell Lymphoma (TCL) [9.4%] Marginal Zone Lymphoma [7.8%]. Compared with NHW participants, Hispanic patients were younger (Median age of 60 vs 66 years), less likely to be male (H 54% vs NHW 66%), less likely to commute more than an hour away from the doctor's office (54% vs 71.8%), had lower household income (income > $100,000 was 32% vs 41.7%) and less likely to have a bachelors' degree or higher (38% vs 50.5%). There were similar prevalence histologies such as DLBCL (H 20% vs NHW 16.5%) and FL (H 36% vs NHW 35%) compared to rarer histologies such as MCL (H 11.1% vs NHW 26.2%) and MZL (H 12% vs NHW 3.9% ) which had disproportional prevalences. Hispanic patients were less likely to have previously participated in a clinical trial (28% vs 51.5%) and less likely to have discussed clinical trials as an option (49% vs 70.9%). A majority of Hispanic (81.0%) and NHW (92.3%) respondents stated that they understood what was meant by a “clinical research study” or “clinical trial” somewhat well or very well. Less than half of Hispanic participants (38.0%) and NHW participants (48.5%) reported being very willing to participate in a cancer clinical trial as their initial course of treatment. The most prevalent concern of both Hispanic and NHW participants respectively was the cost of a clinical trial (34.0%, 22.3%). Other top concerns included distance to the treatment center (32.0%, 13.6%) and frequency of contact with the care team (26.0%, 14.6%). Participants identified access to written materials (69.0%, 60.2%), insurance aid (65.0%, 68.0%), and access to videos (64.0%, 51.5%) as extremely helpful resources that could reduce the burden of participating in a clinical trial. Participants identified that it was most important that a treatment may improve their quality of life by decreasing pain level, increasing activity level, or other symptoms (76.0%, 91.3%). Conclusions Although most Hispanic and NHW participants reported a very good understanding of clinical trials and similar facilitators/barriers for trial participation, Hispanic patients were less likely to have discussed trials as an option with their care teams and less likely to have previously participated in a trial. Evidence-based interventions to address various barriers to clinical trials exist but data on their effectiveness and application is limited. Implementing strategically designed evidence-based interventions to address identified barriers and facilitators will be necessary to improve participation in lymphoma clinical trials.

Introduction: Outcomes from multidisciplinary lymphoma tumor boards in the molecular era are limited, and the effects of transitioning to virtual formats during the COVID-19 pandemic are not well-documented. This study evaluates how the transition of the Mayo Clinic Lymphoma Tumor Board to a virtual format has impacted its effectiveness and operations. The board, part of the International Mayo Clinic Care Network (MCCN), involves case presentations, subspecialist reviews, and collaborative recommendations. Methods: The Mayo Clinic Lymphoma Tumor Board, an integral part of the Mayo Clinic Care Network (MCCN), conducted a comprehensive review of lymphoma cases from 2014 to 2024. The board's review process involves a structured approach including the presentation of clinical case details, radiology and hematopathology findings, proposed treatment options, relevant literature review, and discussions. From 2014 to 2024, the Mayo Clinic Lymphoma Tumor Board reviewed a total of 722 patients. The review process involves a multidisciplinary team, including physicians, pharmacists, clinical research associates, and trainees. Recommendations and changes related to radiology interpretation, pathologic diagnosis, and treatment approaches were documented and tracked prospectively. In March 2020, the board transitioned to a virtual format due to the COVID-19 pandemic. This shift allowed for remote participation and continued collaborative review while maintaining the board's structured approach and documentation practices. Results: In a total of 722 patients, changes in care were identified in 423 patients, including 287 with newly diagnosed lymphoma and 136 with relapse or refractory disease. Among those who experienced changes, 94 had diffuse large B-cell lymphoma, 49 had follicular lymphoma, 39 had marginal zone lymphoma, 36 had classical Hodgkin lymphoma, and 29 had mantle cell lymphoma. Prior to the COVID-19 pandemic, 431 patients were analyzed, with 217 (50.3%) experiencing changes. A total of 268 changes were documented among these patients. Changes in radiologic interpretation occurred in 9 patients (2.1% of 431 total patients). Pathologic diagnosis changes were noted in 42 patients (9.7%). Additional testing was recommended for 73 patients (16.9%), and clinical management was altered for 144 patients (33.4%). After transitioning to a virtual format, 291 patients were reviewed post-COVID, with 206 (70.8%) having recommended changes. The total number of change recommendations was 322, reflecting increases across all components compared to previous data, with adjustments for varying numbers of patients reviewed. Specifically, radiologic interpretation changes occurred in 21 patients (7.2%), pathologic diagnosis changes in 57 patients (19.6%), additional testing recommendations for 85 patients (29.2%), and clinical management alterations in 159 patients (54.7%). Conclusion: Transitioning to a virtual format in the Mayo Clinic Lymphoma Tumor Board's continued to demonstrate the effectiveness, with increased changes in diagnostic interpretations and clinical management. These results illustrate the potential of virtual tumor boards to improve collaborative decision-making and adapt to evolving clinical needs.

Background Underserved patient populations characterized by low income, lack of insurance, low levels of education, and minoritized status face significant barriers when accessing clinical trials. To better understand these challenges, patients from a safety-net county hospital were surveyed on their perspectives on clinical trials, barriers to care, and facilitators of participation. Methods Patients ≥ 18 years old with histologically confirmed non-Hodgkin lymphoma (NHL) who received care at Lyndon B. Johnson Hospital, a safety-net county hospital in Houston, Texas, were invited to participate regardless of treatment status. A self-administered questionnaire was used and offered in English or Spanish. The questionnaire included a total of 53 items with an additional 13 demographic items assessing patient sociodemographic factors and knowledge of clinical trials. Questions also addressed barriers/facilitators of trial participation and respondent willingness to participate in a trial based on certain scenarios. Results Of the 136 patients invited to participate, a total of 49 participants diagnosed with NHL consented to the study and all completed the survey (participation rate 36%). Twenty-seven (55%) surveys were completed in Spanish. Participants self-identified as Hispanic (N=35, 71.4%), African American (N=6, 12.2%), non-Hispanic white (N=7, 14.3%), and Asian/Pacific Islander (N=1, 2%). This cohort included Diffuse Large B-cell lymphoma NOS (DLBCL) [32%], Follicular Lymphoma (FL) [28%], Marginal Zone lymphoma (12%). There were several patients with rare histologies such as Burkitt's lymphoma (4.2%); Mantle Cell lymphoma (4.2%), Plasmablastic lymphoma (4.2%) and T-cell lymphoma (4.1%). The majority of participants reported a commute of less than an hour away to the doctor's office (83%) with almost all participants commuting less than 2 hours (98% with 2% missing an answer). Participants were a median age of 55 years old (range 22-80), majority female (51%), less than a bachelor's degree as highest education (91.8%) and earning < $35,000 (49%). Among respondents, 89.8% had not participated in a clinical trial for their cancer. Only 36.7% of respondents reported that they understood what a clinical research study as “somewhat well,” while 30.6% reported their understanding as “not very well.” Regardless, a majority were very willing (38.8%) or somewhat willing (36.7%) to participate in a trial as their initial course of treatment. Respondents' biggest concerns were the cost of a clinical trial (61.2%), not being able to contact the research team with questions (38.8%), and frequency of clinic visits (32.7%). The most helpful resources that participants identified to reduce participation burden were educational resources such as written materials (77.6%), videos (67.3%), an explanation of the study in their language (65.3%), insurance aid (75.5%), and flexible study visit times (65.3%). Notably, 26.5% of participants responded that they believed they had received medication from a doctor as part of an experiment without their permission. When asked which outcome would most influence their decision to participate in a trial, 79.6% of participants rated the possibility of improving quality of life by decreasing pain and increasing activity levels as very important. Fewer patients (55%) rated other outcomes such as types of side effects (55%) and possibility of pain/discomfort (59%) as very important. Conclusions The majority of patients with NHL who participated in this observational study had little or no previous exposure to or understanding of cancer clinical trials. We identified common barriers to participation including out-of-pocket costs, the ability to contact the research team, and the frequency of clinic visits that should be addressed with specific identified resources to reduce participation burden. Interventions guided by these data should be implemented and evaluated to improve clinical trial participation for patients with lymphoma.

Background: FL3B is the least common among FL subtypes, accounting for 5-10% of cases. Almost half of FL3B tumors have concurrent diffuse large B cell lymphoma (DLBCL) in the diagnostic tissue biopsy, while FL3B rarely coexists with FL1-2 or FL3A. Several lines of evidence suggest that FL3B displays distinct biological and clinical characteristics resembling aggressive DLBCL rather than the indolent FL1-3A. Accordingly, DLBCL anthracycline-containing regimens, such as R-CHOP, are the mainstay of therapy for FL3B with or without coexisting DLBCL. However, while some studies show that R-CHOP therapy in FL3B was associated with 5-year overall survival (OS) rate of 54%, others report outcomes comparable to FL3A with 79-90% survival. Additional controversy involves the clinical implication of pure FL3B (FL3Bp) vs FL3B with concurrent DLBCL (FL3Bc). Thus, it remains unclear if FL3B clinically resembles DLBCL or lower-grade FL and whether FL3Bp has a different prognosis from FL3Bc. To address these questions, we performed a pooled study of two large prospective multicenter study cohorts to compare the clinical characteristics and outcomes of newly diagnosed FL3B with FL1-2, FL3A and DLBCL patients, all of whom were uniformly treated with frontline R-CHOP. Patients and Methods: Weevaluated 469 newly diagnosed patients with FL1-2 (n=216), FL3A (n=170) and FL3B (n=83) who received R-CHOP within 6 months of diagnosis and 739 de novo DLBCL (GCB n=455 and non-GCB n=284) who were prospectively enrolled into the Molecular Epidemiology Resource (MER) and the Lymphoma Epidemiology of Outcomes (LEO) cohorts between 2002 and 2021. FL3B cases were designated as FL3Bc and FL3Bp based on the presence or absence of coexisting DLBCL, respectively. Histologic diagnosis was determined by an expert pathologist at each participating center and centrally reviewed. Event free survival (EFS) and OS were defined as time from diagnosis to progression, relapse, retreatment or death, and early progression defined as failing to achieve EFS at 24 months (EFS24). Associations between clinical features and EFS or OS were evaluated using Kaplan Meier curves and Cox proportional hazards models unadjusted and adjusted for age and FLIPI (comparisons with FL1-2 and FL3A) or IPI (comparisons with DLBCL). Results: The median age was 61 years (range, 18-94 years). Among FL3B patients, 21 (25%) had FL3Bc and 62 (75%) FL3Bp. Baseline characteristics and outcomes were broadly similar between the two FL3B subtypes. We then compared all FL3B patients to those with lower-grade FL. Patients with FL3B showed similar clinical features to those with FL1-2 and FL3A, with exception for a lower tumor burden. After R-CHOP, FL1-2 patients had an inferior EFS (HR 2.13 95%CI 1.31-3.46) than those with FL3B, whereas there was no difference compared to FL3A. OS was similar across all FL grades. Although FL1-2 patients failed to achieve EFS24 more frequently than FL3B and FL3A (34% vs 18% and 15%, p<0.001), FL3B patients who did fail EFS24 had almost three folds higher risk of subsequent mortality (HR 2.84 95%CI 1.35-6.01) than other FLs. At 5-year follow-up, FL3B patients had twice the risk of relapse with an aggressive subtype (i.e., DLBCL, high-grade B-cell lymphoma) than those with FL1-2 and FL3A, who instead often recurred with indolent disease (i.e., FL1-2, FL3A; p<0.001). We further compared FL3B patients to those with DLBCL classified based on cell-of-origin into GCB and non-GCB subtypes. At diagnosis, patients with FL3B had more favorable clinical features than those with GCB and non-GCB DLBCL. Compared to FL3B, patients with non-GCB DLBCL had an inferior EFS (HR 1.73 95%CI 1.07-2.79) and OS (HR 2.04 95%CI 1.11-3.75), while those with GCB DLBCL did not show a significant difference in EFS (HR 1.41 95%CI 0.88-2.25) or OS (HR 1.69, 95%CI 0.93-3.06) likely due to insufficient statistical power. Patients with FL3B failed EFS24 less frequently than patients with GCB or non-GCB DLBCL (17% vs 25% and 32%; p=0.01). Among patients who failed EFS24, those with FL3B had a similar subsequent OS as both GCB (HR 1.41 95%CI 0.73-2.72) and non-GCB DLBCL (HR 1.27 95%CI 0.65-2.47). Conclusions: We report that FL3Bp and FL3Bc appear clinically similar. While most FL3B patients have a prognosis comparable to FL1-2 and FL3A, 18% exhibit aggressive behavior with poor outcome reminiscent of DLBCL. Future studies with a larger population will be needed to confirm our findings.

Introduction: Diffuse large B cell lymphoma (DLBCL) patients experience favorable outcomes following frontline immunochemotherapy, however, 30-40% of patients will exhibit primary refractory disease or relapse (rrDLBCL). Recent studies have expanded upon well-defined characteristics of newly diagnosed DLBCL (ndDLBCL) to elucidate genomic landscapes underlying rrDLBCL; yet, high-throughput examination of resistance and relapse mechanisms within rrDLBCL subtypes, including the newly defined dark zone signature (DZsig) addition to cell of origin (COO), have yet to be described. To expand upon the current tumor etiology and define subtype-specific driving mechanisms, we describe a multi-omic analysis leveraging clinical and biologic variables in rrDLBCL. Methods: Tumor biopsies (N=228) collected at the time of relapse were obtained from n=85 participants in the Mayo Clinic/University of Iowa Lymphoma Molecular Epidemiology Resource (MER), n=73 in the Mayo Clinic Biobank, and n=38 from CC-122-DLBCL-001 or n=32 CC-122-ST-001 trials. Tumor samples were analyzed by WES (n=158) or WGS (n=70) and by RNAseq (n=145). Comparative analysis against ndDLBCL MER samples (N=444) utilized WES (n=404) and RNAseq (n=321). Chi Square or Fisher's exact test was used for enrichment analysis of categorical variables, while Wilcoxon or Kruskal-Wallis test was used for continuous variables. Results: rrDLBCL samples were enriched for ABC (46% vs 33% in ndDLBCL, p=0.01), and fewer GCB (27% vs 40%, p=0.006). Amongst rrDLBCL patients, variance in overall survival (from time of original diagnosis; log-rank p=0.001) was observed between COO subtypes, with poor outcomes in patients with DZsig (median 15.0 mo) and GCB (36.5 mo) compared to ABC tumors (74.4 mo). Patients with progression or relapse within 6 months featured a more even COO distribution (ABC - 22%, GCB - 34%, DZsig - 28%) than patients with early (6-24 mo; 51%, 22%, 22%) or late relapses (>24 mo; 62%, 19%, 4%), which were predominantly ABC. Comparing mutation frequency within subtypes, rrDLBCL GCB tumors were enriched for B2M (41% vs 15% in ndDLBCL, p=0.002), EP300 (19% vs 7%, p=0.059), CIITA (19% vs 5%, p=0.02), PRKCB (11% vs 2%, p=0.035), CD79B (11% vs 0%, p=0.004), and CD83 (8% vs 1%, p=0.049) mutations, and CNV events including gains at 8q24.21 (MYC locus; 48% vs 14%, p<0.001) and 18q21.33 (BCL2, TCF4 locus; 36% vs 15%, p=0.021), and losses at 17p13.1 (TP53 locus; 40% vs 19%, p=0.035). rrDLBCL DZsig tumors featured enrichment for BCL6 (22% vs 3%, p=0.025), and SPEN (17% vs 3%, p=0.062) mutations and 2q22.2 losses (LRP1B locus; 20% vs 0%, p=0.019). Despite differential mutation and CNV profiles, gene expression analysis revealed minimal variance within COO subtypes in rrDLBCL and ndDLBCL, however upregulation of lymphoma driving genes including MYBPC2 (LogFC=1.68, FDR<0.001), MYOM2 (LogFC=1.33, FDR=0.007), MYC (LogFC=0.61, FDR=0.04), and CELSR2 (LogFC=0.53, FDR=0.02) were observed in ABC rrDLBCL. Increased frequency of LymphGen classifier A53 was observed in ABC (43% vs 17%, p=0.005) and GCB (40% vs 14%, p=0.009) rrDLBCL. Using CIBERSORTx to infer lymphoma microenvironment (LME) cell type abundance, an LME-depleted class was evident in rrDLBCL tumors, including reduction of CD8+ T cells (effect size (r)=-0.78, p<0.001) and T follicular helper cells (r=-0.48, p=0.012) in GCB rrDLBCL and reduction of T follicular helper cells (r=-0.43, p=0.023) and Tregs (r=-0.32, p=0.065) in DZsig rrDLBCL. Significance: We present an update to the genomic landscape of rrDLBCL, highlighting GCB and DZsig tumors with differential biology and advanced clinical course. Our data supports increased implementation of sequencing efforts in rrDLBCL to more broadly evaluate relapse mechanisms, with optimism that a more detailed understanding of r/r disease may guide trials for targeted treatment strategies. For example, rrDLBCL patients may be strong candidates for MYC pathway targeting agents (BETi), or a Lenalidomide-based regimen (R2 or Tafa-Len), as Lenalidomide has been shown to reprogram the LME via PD-L1 expression in addition to downregulation of MYC and MYC target genes. Or, due to enrichment of variants affecting anti-apoptotic proteins including BCL6 or BCL2 in DZsig and GCB rrDLBCL, a venetoclax-based therapeutic may be considered. Further targeted strategies should be considered as development of a more personalized approach remains an unmet need.

Background: Immunochemotherapy is the current standard-of-care frontline therapy for diffuse large B-cell lymphoma (DLBCL). Our group previously reported that addition of the mTOR inhibitor everolimus to R-CHOP resulted in excellent efficacy in the Alliance N1085 trial (Witzig TE et al, Blood Cancer J, 2017, 7(6):e576), with 23 of 24 patients achieving event-free survival at 24 months (EFS24), supporting further investigation of PI3K/mTOR targeting in DLBCL. New insights into molecular classification of DLBCL suggest that multiple genetic subtypes of DLBCL (eg, MCD, BN2, ST2, and EZB per LymphGen classification) may be susceptible to PI3K/mTOR targeting. Therefore, we conducted a phase 1/1b trial to investigate the safety and efficacy of combination therapy with a novel PI3K inhibitor parsaclisib and standard immunochemotherapy. Methods: Adult patients with newly diagnosed DLBCL were eligible if any of the following was present: 1) non-GCB subtype per the Hans algorithm; 2) protein expression of either MYC (≥40%) or BCL2 (≥50%) by immunohistochemistry; or 3) MYC rearrangement by FISH. Patients with high grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements were also eligible. Phase 1 followed a 3+3 design to determine the maximum tolerated dose (MTD) of parsaclisib (plus R-CHOP) to be used in Phase 1b (dose expansion). The primary efficacy endpoint in phase 1/1b was complete response (CR) rate by PET. A polatuzumab vedotin (Pola) safety lead-in cohort was added later to explore the safety and efficacy of parsaclisib (at MTD) plus Pola-R-CHP. Results: From July 2020 to May 2023, 50 patients were enrolled; 1 patient withdrew consent before study treatment and was excluded from this analysis. Nine patients were treated in Phase 1, 33 in Phase 1b, and 7 in the Pola cohort. The median age at diagnosis was 66 years (range 20-86), and 20 (41%) were female. Two (4%) patients had ECOG PS ≥2, 26 (53%) had elevated LDH, 19 (39%) had >1 extranodal site, 37 (76%) had stage III/IV, and 25 (51%) had high-intermediate or high-risk International Prognostic Index (3-5). 23 (47%) had non-GCB subtype, 23 (46.9%) had MYC or BCL2 single expression, 21 (42.9%) had MYC/BCL2 double expression, and 6 (12%) had MYC rearrangement (2 with BCL2 and/or BCL6 rearrangements). In Phase 1, 3 patients were treated at dose level 1 (parsaclisib 20 mg QD, d1-10) and 6 at dose level 2 (parsaclisib 20 mg QD, d1-14). No dose limiting toxicity was observed. Therefore, dose level 2 for parsaclisib was the MTD and was used in Phase 1b. In the Pola cohort (n=7), only 1 of 6 evaluable patients experienced significant toxicity (grade 3 diarrhea). Among all 49 patients, the most common treatment-related adverse event (TRAE) of any grade included neutropenia (83.7%), thrombocytopenia (79.6%), leukopenia (77.6%), lymphopenia (71.4%), anemia (71.4%), nausea (63.3%), fatigue (40.8%), peripheral sensory neuropathy (36.7%), constipation (24.5%), and diarrhea (22.4%), and the most common grade ≥3 TRAE included neutropenia (71.4%), leukopenia (69.4%), lymphopenia (49.0%), thrombocytopenia (20.4%), anemia (16.3%), febrile neutropenia (6.1%), and diarrhea (6.1%). In Phase 1/1b (n=42), the overall response rate (ORR) to parsaclisib plus R-CHOP was 97.6%, and the CR rate was 90.5%. After a median follow-up of 28.5 months (95% CI 27.7-32.7), the estimated 2-year progression-free survival (PFS) rate was 84.6% (95% CI 73.9-96.8), and the estimated 2-year overall survival (OS) rate was 95.1% (95% CI 88.7-100.0). In the Pola cohort, the ORR to parsaclisib plus Pola-R-CHP was 100% and the CR rate was 100%. After a median follow-up of 15.6 months (95% CI 13.5-NE), 1 patient had disease relapse at 11.95 months, and all patients were alive. Conclusions: Addition of the PI3K inhibitor parsaclisib to R-CHOP or Pola-R-CHP immunochemotherapy is considered safe in patients with newly diagnosed DLBCL. Combination of parsaclisib and standard immunochemotherapy resulted in high ORR and CR rate and encouraging preliminary PFS and OS outcomes patients with high-risk DLBCL. These data support further investigation of PI3K/mTOR targeting in newly diagnosed DLBCL in future trials.