Trials In Lymphoma Research Articles

Polatuzumab Vedotin for Diffuse Large B-Cell Lymphoma: Innovation's Allure versus a Time-Honored Tradition

AbstractChemotherapy with R-CHOP (rituximab, cyclophosphamide, Adriamycin, vincristine, prednisolone) is the standard of care for patients with diffuse large B-cell lymphoma as the first-line therapy. The recent approval of polatuzumab as the first-line therapy after demonstration of its efficacy in the Polatuzumab Vedotin in Previously Untreated Diffuse Large B-Cell Lymphoma (POLARIX) trial is the first significant change in this treatment regimen over two decades. This concise appraisal of trial evidence and clinical context highlights the limited potential for a clinically significant benefit with the addition of polatuzumab to the first-line therapy for this common hematologic malignancy.

Histone marks identify novel transcription factors that parse CAR-T subset-of-origin, clinical potential and expansion.

Chimeric antigen receptor-modified T cell (CAR-T) immunotherapy has revolutionised blood cancer treatment. Parsing the genetic underpinnings of T cell quality and CAR-T efficacy is challenging. Transcriptomics inform CAR-T state, but the nature of dynamic transcription during activation hinders identification of transiently or minimally expressed genes, such as transcription factors, and over-emphasises effector and metabolism genes. Here we explore whether analyses of transcriptionally repressive and permissive histone methylation marks describe CAR-T cell functional states and therapeutic potential beyond transcriptomic analyses. Histone mark analyses improve identification of differences between naïve, central memory, and effector memory CD8 + T cell subsets of human origin, and CAR-T derived from these subsets. We find important differences between CAR-T manufactured from central memory cells of healthy donors and of patients. By examining CAR-T products from a clinical trial in lymphoma (NCT01865617), we find a novel association between the activity of the transcription factor KLF7 with in vivo CAR-T accumulation in patients and demonstrate that over-expression of KLF7 increases in vitro CAR-T proliferation and IL-2 production. In conclusion, histone marks provide a rich dataset for identification of functionally relevant genes not apparent by transcriptomics.

Fermented Wheat Germ Protein with Histone Deacetylase Inhibitor AR42 Demonstrates Enhanced Cytotoxicity against Lymphoma Cells In Vitro and In Vivo.

Current treatments for lymphoma are plagued by substantial toxicity and the inability to overcome drug resistance, leading to eventual relapse and rationalizing the development of novel, less toxic therapeutics and drug combinations. Histone deacetylase inhibitors (HDACis) are a broad class of epigenetic modulators that have been studied in multiple tumor types, including lymphoma. Currently, HDACis are FDA-approved for treating relapsed T-cell lymphomas and multiple myeloma, with ongoing trials in other lymphomas and solid tumors. As single agents, HDACis frequently elicit toxic side effects and have limited efficacy; therefore, many current treatment strategies focus on combinations to boost efficacy while attempting to minimize toxicity. Fermented wheat germ extract (FWGE) is a complementary agent that has shown efficacy in several malignancies, including lymphoma. Here, we utilize a more potent FWGE derivative, known as fermented wheat germ protein (FWGP), in combination with the HDACi AR42, to assess for enhanced activity. We report increased in vitro killing, cell cycle arrest, and in vivo efficacy for this combination compared to each agent alone with minimal toxicity, suggesting a potentially new, minimally toxic treatment modality for lymphoma.

Evaluating the impact of laboratory-based eligibility criteria by race/ethnicity in first-line clinical trials of DLBCL

AbstractUnderrepresentation of racial and ethnic subgroups in cancer clinical trials remains a persistent challenge. Restrictive clinical trial eligibility criteria have been shown to exacerbate this problem. We previously identified that up to 24% of patients treated with standard immunochemotherapy would have been excluded from recent first-line trials in diffuse large B-cell lymphoma (DLBCL) based on 5 laboratory-based criteria. These ineligible patients had worse clinical outcomes and increased deaths related to lymphoma progression, suggesting the potential exclusion of patients who could have benefited most from the novel therapies being evaluated. Using data from the prospectively enrolled Lymphoma Epidemiology Outcomes cohort study, with demographics broadly similar to the US patients diagnosed with lymphoma, we evaluated the impact of laboratory eligibility criteria from recent first-line DLBCL trials across various racial and ethnic backgrounds. There were significant differences in the baseline laboratory values by race/ethnicity with Black/African American (AA) patients having the lowest mean hemoglobin and highest creatinine clearance. Based on recent clinical trial eligibility criteria, AA and Hispanic patients had higher rates of laboratory-based ineligibility than non-Hispanic White patients. The largest gap in the clinical outcomes between eligible and noneligible patients was noted within AA patients with an overall survival hazard ratio based on POLARIX clinical trial criteria of 4.09 (95% confidence interval, 1.83-9.14). A thoughtful approach to the utility of each criterion and cutoffs for eligibility needs to be evaluated in the context of its differential impact across various racial/ethnic groups.

Development and testing of a lymphoma clinical trial-specific frailty index: a secondary analysis of the NCIC-CTG LY.12 clinical trial

The prevalence of frailty in clinical trials of lymphoma is unknown. We conducted a secondary analysis of the phase III LY.12 trial in which patients with relapsed aggressive non-Hodgkin lymphoma were randomized to different salvage regimens before autologous stem cell transplant. The primary objective was to construct a lymphoma clinical trials-specific frailty index (LyFI) using previously described methods. The secondary objective was to describe the association of frailty withover all and event-free survival (OS, EFS). The LyFI was constructed using 619 patients, and11% (N = 70) were classified as frail. Frailty was associated with EFS (HR 1.94, 95%CI 1.53–2.46) and OS (HR 2.01, 95%CI 1.57–2.58) in univariable analysis, but was only significant as a continuous (not binary) variable in multivariable analysis controlling for prognostic score, suggesting limitations of a FI in this trial population. Future work could validate the FI using clinical assessments and/or apply it to an older trial population.

Abstract PO-031: Systematic discovery of chemotherapy response biomarkers in Peripheral T Cell Lymphomas

Abstract Background. Identifying which patients will benefit from individual therapies remains a general challenge in oncology. Predictive biomarkers of drug sensitivity, when known, can increase the rate of success of trials, and allow stratification of patients for targeted combination therapies, as recent shown by the GUIDANCE-01 trial in Large B-Cell Lymphoma. Peripheral T-Cell Lymphomas (PTCL) could particularly benefit from this approach, being heterogeneous diseases against which many therapies are active in unpredictable subsets of patients. A central challenge of biomarker discovery is finding true determinants of drug response, which may be multiple genes, among thousands of molecular features that may accidentally correlate. Here, we aim to mitigate this challenge by combining functional genetic screens and gene expression profiling in diverse PTCL cultures, to enable the systematic discovery of drug sensitivity biomarkers. Methods. To discover genes whose expression directly modifies drug sensitivity, we conducted genome-wide CRISPR screens with PTCL cells under treatment with five therapies with clinical activity in PTCL: Romidepsin, Pralatrexate, Gemcitabine, Oxaliplatin, and Bortezomib. To discover genes whose basal expression significantly correlates with specific drug sensitivities, we measured RNAseq and drug response functions for a diverse panel of 27 PTCL cultures. Genes in the intersection of both experiments are causally related to and correlate with drug responses in PTCL, and have the statistical benefit of detection by independent methods. Results. Functional genetic screens on therapy provided mechanistic insights for each drug of interest, and identified genes whose perturbation affects drug sensitivity. Whereas hundreds of genes nominally correlate with drug sensitivity in cell line panels, for each drug a shortlist of only 5 to 20 genes are both CRISPR hits and correlate with response across PTCL cultures. For each drug tested, multi-gene sensitivity scores constructed from hits stratify PTCL cultures into statistically distinct sensitive and non-sensitive subgroups (Mann Whitney P-Values <0.01). These genes’ relationships to drug mechanisms were often supported by prior studies, including functions in DNA repair, cell cycle regulation, and solute carriers required for cellular entry of specific therapies, such as SLC19A1 for Pralatrexate and SLC43A2 for Oxaliplatin. Conclusions. Combining functional genetic screens and correlative drug sensitivity measurements narrowed the search for predictive biomarkers of drug sensitivity, and may be a general means of refining biomarker hypotheses for validation in clinical datasets. Although chemotherapy sensitivity is commonly polygenic, multi-gene scores based on few mechanistically-related genes were able to significantly distinguish drug sensitive from resistant PTCLs. These approaches provide novel hypotheses for drug-gene relationships that may serve as the basis for molecular subtyping of individual lymphomas for precision regimens. Citation Format: Adam C Palmer, Jacob C Pantazis. Systematic discovery of chemotherapy response biomarkers in Peripheral T Cell Lymphomas [abstract]. In: Proceedings of the Fourth AACR International Meeting on Advances in Malignant Lymphoma: Maximizing the Basic-Translational Interface for Clinical Application; 2024 Jun 19-22; Philadelphia, PA. Philadelphia (PA): AACR; Blood Cancer Discov 2024;5(3_Suppl):Abstract nr PO-031.

Emavusertib (CA-4948) in combination with ibrutinib in patients with relapsed/refractory primary central nervous system lymphoma (R/R PCNSL).

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 .

The Glass Wall: Gendered Authorship Disparities in CD 19 and BCMA CAR-T Clinical Trials for Lymphoma and Myeloma

IntroductionExisting literature suggests that women are significantly underrepresented in the field of hematology-oncology. Women make up 35.6% of hematologists and data on females as site investigators for pivotal trials and authors in publications of pivotal trials in hematologic malignancies, specifically in the novel niche of Chimeric antigen receptor T cell (CAR-T), is sparse. MethodsWe examined the proportion of women in pivotal trials, screening a total of 2180 studies from PubMed using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. 2180 initially searched records were filtered by date (2017-2023) and clinical trial status, yielding 149 records. Following a manual review, we included 15 studies that led to the approval of or anticipated approval of CD19 and BCMA CAR-T therapies in lymphoid and plasma cell malignancies. We examined overall number of female authors, number of lead female authors, and ratio of all authors to female authors in the 15 trials, which were all high impact, cited on average 1314 times. ResultsOf the 436 authors assessed, 132 were female, correlating to 29.5% female authorship. The only study with female authorship >50% was ELIANA, a 2017 pediatric study. 7 of the 15 studies had female lead authors; notably, 6 out of 7 of these studies were published in 2021 or later. ConclusionIn conclusion, our data suggests gender iniquities for female investigators exist in the field of immune effector cell therapy. We suggest further investigation and strategies to decrease gendered authorship disparities.

Multiomics analysis identifies oxidative phosphorylation as a cancer vulnerability arising from myristoylation inhibition

BackgroundIn humans, two ubiquitously expressed N-myristoyltransferases, NMT1 and NMT2, catalyze myristate transfer to proteins to facilitate membrane targeting and signaling. We investigated the expression of NMTs in numerous cancers and found that NMT2 levels are dysregulated by epigenetic suppression, particularly so in hematologic malignancies. This suggests that pharmacological inhibition of the remaining NMT1 could allow for the selective killing of these cells, sparing normal cells with both NMTs.Methods and resultsTranscriptomic analysis of 1200 NMT inhibitor (NMTI)-treated cancer cell lines revealed that NMTI sensitivity relates not only to NMT2 loss or NMT1 dependency, but also correlates with a myristoylation inhibition sensitivity signature comprising 54 genes (MISS-54) enriched in hematologic cancers as well as testis, brain, lung, ovary, and colon cancers. Because non-myristoylated proteins are degraded by a glycine-specific N-degron, differential proteomics revealed the major impact of abrogating NMT1 genetically using CRISPR/Cas9 in cancer cells was surprisingly to reduce mitochondrial respiratory complex I proteins rather than cell signaling proteins, some of which were also reduced, albeit to a lesser extent. Cancer cell treatments with the first-in-class NMTI PCLX-001 (zelenirstat), which is undergoing human phase 1/2a trials in advanced lymphoma and solid tumors, recapitulated these effects. The most downregulated myristoylated mitochondrial protein was NDUFAF4, a complex I assembly factor. Knockout of NDUFAF4 or in vitro cell treatment with zelenirstat resulted in loss of complex I, oxidative phosphorylation and respiration, which impacted metabolomes.ConclusionsTargeting of both, oxidative phosphorylation and cell signaling partly explains the lethal effects of zelenirstat in select cancer types. While the prognostic value of the sensitivity score MISS-54 remains to be validated in patients, our findings continue to warrant the clinical development of zelenirstat as cancer treatment.

Learnings from phosphatidylinositol 3-kinase inhibitors in lymphoma-Moving to a model where less can be more.

The role of Pi3K inhibitors in lymphoma is diminishing due to the adverse results from trials in indolent lymphoma, but is a one-size-fits-all approach to drug development penalising some lymphoma subtypes and the newer generation of Pi3K inhibitors? The report by Soumerai etal. of zandelisib with zanubrutinib in follicular and mantle cell lymphoma is an important addition to the data. Commentary on: Soumerai etal. Safety and efficacy of zandelisib plus zanubrutinib in previously treated follicular and mantle cell lymphomas. Br J Haematol 2024;204:1762-1770.

Abstract 5720: Targeting CDK9 in cutaneous T-cell lymphoma using patient-derived xenograft models

Abstract Cutaneous T-cell lymphoma (CTCL) is a rare form of non-Hodgkin lymphoma. Mycosis fungoides and Sézary syndrome (MF/SS) are the most common subtypes in CTCL. Early-stage MF/SS has a favorable prognosis. The advanced-stage CTCL has limited treatment options and a median survival of <5 years, highlighting the urgent need to develop targeted therapies in CTCL. Preclinical studies of CDK9 inhibitors have shown anti-tumor activity in various subtypes of hematologic malignancies. Several CDK9 inhibitors have entered clinical trials for lymphomas and leukemias. However, whether targeting CDK9 in CTCL is a therapeutic option is little known and has resulted in CTCL not being included in ongoing clinical investigations of CDK9 inhibitors. AZD4573 is a highly selective and potent CDK9 inhibitor currently under clinical investigation for Hodgkin and non-Hodgkin lymphomas. It was shown that AZD4573 induces tumor cell death through depletion of MCL-1. Overexpression of MCL-1 has been shown in CTCL cell lines and skin biopsy specimens of CTCL patients. MCL-1 expression appears to be particularly elevated in patients with advanced stage disease. Here, we investigated the ex vivo anti-tumor activity of AZD4573 using patient-derived CTCL xenograft models (PDXs). Primary tumor cells harvested from CTCL PDX mice were activated with CD2/CD3/CD28 beads and incubated in hIL-2 and hIL-7 at an optimal cell density. Subsequently, cells were exposed to AZD4573 at various concentrations for 8 hr, then treated cells were harvested, washed, and placed in fresh media for another 48 hr. Growth inhibition was measured by the Real-Time Glo cell viability assay, and apoptotic activity was assessed by flow cytometry analysis of Caspase 3/7 activity and Annexin V + propidium iodide (PI) double staining. Additionally, we conducted RNA-seq analysis for MCL-1 expression in CTCL PDX primary tumor cells. AZD4573 inhibited cell proliferation in a dose-dependent manner in primary tumor cells from three CTCL PDX mice (PRS-1, PRS-2 PRS-3), with GI50 of 43.5 nM, 175.4 nM, and 113.5 nM, respectively. Furthermore, AZD4573 significantly increased caspase 3/7 activity and apoptosis in PRS-1 and PRS-3, but not PRS-2 primary tumor cells. In addition, our RNA-seq analysis showed that compared with normal controls (normal PBMC from healthy donors), the MCL-1 gene expression is increased 10-fold (P-value <0.0001) in PRS1 cells. The MCL-1 gene expression in PRS2 and PRS3 cells is the same as normal control. Furthermore, PRS-1, which has the highest MCL-1 expression level, is most sensitive to AZD4573. In conclusion, AZD4573 demonstrated dose-dependent growth inhibition and apoptosis induction in primary CTCL tumor cells. In addition, the expression level of MCL-1 appeared to be correlated with the ex vivo anti-tumor activity of AZD4573. Our findings provide a rationale for clinical investigation of targeting CDK9 in CTCL. Citation Format: Yan-Jin Liu, Chi-Heng Wu, Laura Pincus, Weiyun Z. Ai. Targeting CDK9 in cutaneous T-cell lymphoma using patient-derived xenograft models [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 5720.

The Glass Wall: Gendered Authorship Disparities in in CD 19 and BCMA CAR-T Clinical Trials for Lymphoma and Myeloma.

The Glass Wall: Gendered Authorship Disparities in in CD 19 and BCMA CAR-T Clinical Trials for Lymphoma and Myeloma.

Endpoints in clinical trials in diffuse large B-cell lymphoma: time for more dialogue?

We observed lack of clarity and consistency in end point definitions of large randomized clinical trials in diffuse large B-cell lymphoma. These inconsistencies are such that trials might, in fact, address different clinical questions. They complicate interpretation of results, including comparisons across studies. Problems arise from different ways to account for events occurring after randomization including absence of improvement in disease status, treatment discontinuation or the initiation of new therapy. We call for more dialogue between stakeholders to define with clarity the questions of interest and corresponding end points. We illustrate that assessing different end point rules across a range of plausible patient journeys can be a powerful tool to facilitate such a discussion and contribute to better understanding of patient-relevant end points.

Predicting Phase 1 Lymphoma Clinical Trial Durations Using Machine Learning: An In-Depth Analysis and Broad Application Insights.

Lymphoma diagnoses in the US are substantial, with an estimated 89,380 new cases in 2023, necessitating innovative treatment approaches. Phase 1 clinical trials play a pivotal role in this context. We developed a binary predictive model to assess trial adherence to expected average durations, analyzing 1089 completed Phase 1 lymphoma trials from clinicaltrials.gov. Using machine learning, the Random Forest model demonstrated high efficacy with an accuracy of 0.7248 and an ROC-AUC of 0.7677 for lymphoma trials. The difference in the accuracy level of the Random Forest is statistically significant compared to the other alternative models, as determined by a 95% confidence interval on the testing set. Importantly, this model maintained an ROC-AUC of 0.7701 when applied to lung cancer trials, showcasing its versatility. A key insight is the correlation between higher predicted probabilities and extended trial durations, offering nuanced insights beyond binary predictions. Our research contributes to enhanced clinical research planning and potential improvements in patient outcomes in oncology.

Why We Fail: An Analysis of Terminated Interventional Clinical Trials in Lymphoma

Introduction: Clinical trials serve as the cornerstone for advancing therapeutic and clinical strategies in Lymphoma. Learning from prematurely terminated trials provides valuable insights for researchers and drug developers. This study analyses interventional clinical trials in lymphoma terminated between 2010 and 2023, aiming to identify common factors contributing to their failure and improve future research in Lymphoma. Methods The study identified clinical trials in Lymphoma registered in the US between 01/01/2010, and 01/07/2023, using the InovaSight platform. The analysis included trials investigating drugs in phases I-III with at least one recruited patient. Phase 4 studies, early access programs, and trials examining medical devices were excluded, as were trials terminated early due to positive efficacy signals. Natural language processing (NLP) & classification algorithms were used to categorize trials into distinct phases of clinical development and were also applied to identify reasons for trial termination from official registrations and relevant publications. These reasons were then characterized using the InovaSight trial ontology for thematic analysis. Enriching features, including mechanism of action information, design characteristics, target enrolment, and inclusion criteria, were generated and linked for each eligible trial. The analysis was conducted using the InovaSight drug development platform, which employs responsible artificial intelligence to expedite the development of novel therapeutics for haematological malignancies. Results: A total of 306 trials met the inclusion criteria, with phase II trials being most frequently withdrawn (49.3%), followed by phase I (42.5%) and phase III (8.2%). The trials spanned from 2010-01-31 to 2021-12-15. Among terminated studies, single-arm trials were most frequent (64%), followed by two-armed designs (21.2%) and three or more arms (14.7%). A concentration of mechanisms of action were observed across all phases (further described in poster). Reasons for early termination included enrolment issues, sponsor decisions, lack of efficacy, safety concerns, funding withdrawal, investigator-related issues, study irrelevance, drug supply problems, COVID-19, and unspecified reasons. The most common reason for early termination was enrolment issues in Phase I and Phase II studies, and sponsor decisions in Phase III studies. Detailed results are presented in Figure 1. Discussion: Our analysis identified a total of 306 trials that met the inclusion criteria, encompassing different phases of clinical development. Interestingly, phase II trials were the most frequently withdrawn, followed by phase I and phase III trials. This observation suggests that a considerable number of trials face challenges during the intermediate stages of development, which could be attributed to various factors such as safety concerns, lack of efficacy, or financial constraints. Our analysis revealed a concentration of similar mechanisms of action across all trial phases. This finding suggests that certain therapeutic areas or drug targets may be more prone to early termination. Exploring the underlying reasons for this pattern could provide valuable insights for future trial planning and design (This is further elucidated in the full presentation). Among the various reasons for early termination, enrolment issues emerged as the most common factor in both Phase I and Phase II studies. This highlights the critical need for in depth and principled approaches to study feasibility assessment routed in an evidence-based methodology. In contrast, sponsor decisions were the leading cause of termination in Phase III trials. This finding suggests that late-stage trials are more susceptible to decisions made by the trial sponsors, which could be influenced by factors such as financial considerations or market dynamics. The results underscore the importance of careful trial planning, patient recruitment strategies, and effective collaboration between sponsors, investigators, and regulatory bodies. Understanding the challenges and factors contributing to trial termination can aid in optimizing future trial designs, mitigating risks, and improving the efficiency of drug development processes.

Are Pivotal CART Trials Representative of Population at Risk?

Introduction Since 2017, 6 chimeric antigen receptor T-cell (CAR-T) therapies have been approved for Acute Lymphoblastic Leukemia (ALL), Mantle Cell Lymphoma (MCL), Diffuse Large B-cell Lymphoma (DLBL), Follicular Lymphoma (FL), and Multiple Myeloma (MM) and have changed the treatment landscape immensely. There is significant demographic and geographic under-representation in pivotal clinical trials leading to drug approvals for leukemias, lymphomas and MM compared with the population affected. We investigated whether similar disparities exist in pivotal CAR-T trials. Method Clinical Trials leading to CAR-T approval were identified from the US Food and Drug Administration databases. Demographic data was collected from clinicaltrials.gov and primary manuscripts. Standard descriptive statistics were used to analyze the data with stratification by race, ethnicity, sex, and malignancy subtypes. Total incidence of respective malignancies and the demographic representation was obtained from SEER data. Results A total of 10 out of 11 (90.91%) clinical trials leading to CAR-T approval reported data on race and 8 (72.72%) on ethnicity. These trials led to approvals for MM, non-Hodgkin lymphoma (DLBCL, FL and MCL), and ALL. These trials included 1441 patients of which 1155 (80.15%) were reported as White. NCT02445248, for Tisagenlecleucel (tisa-cel) lacked racial data and was excluded from analysis. Data are summarized in Table 1. For MM, 2 CARTs have been approved, Idecabtagene vicleucel and Ciltacabtagene autoleucel (cilta-cel). African American (AA) representation in these pivotal trials, NCT03361748 and NCT03548207 (CARTITUDE-1), respectively was 4.7 % and 17.5 %. In contrast, SEER data shows that AA population represent 21% of the incident MM cases over the last 5 years (2016-2021). In ALL, 2 CARTs, tisa-cel and Brexucabtagene Autoleucel (brexu-cel) have been approved. AAs had 0.55% of representation in the CAR-T ALL clinical trials, whereas they represent 7.5% of all ALL cases in the past 5 years. For follicular lymphoma, Tisa-cel and Axicabtagene ciloleucel (Axi-cel) have been approved as third line treatment. For DLBCL, lisocabtagene maraleucel (liso-cel), tisa-cel and axi-cel have been approved as third line with liso-cel and axi-cel also having second line DLBCL indication. Brexu-cel has been approved for third line MCL. Under-representation of AAs with respect to disease distribution was noted in all these trials. Female patients were also disproportionately under-represented in lymphoma trials overall. Ethnicity was reported less frequently in aforementioned studies but available data suggests Hispanic groups being underrepresented in these trials. Conclusion There are significant demographic under-representations and imbalances in pivotal clinical trials leading to CART approval compared with the population affected. Efforts need to be directed at ensuring racial and ethnic inclusivity and equity in trials for better applicability to the “real world”. Trials should also consistently report demographic data, especially ethnic and racial, for better transparency and accurate analysis of presented data.

Demographic Disparities in Clinical Trial Enrollment of US Patients with Newly-Diagnosed Multiple Myeloma

Background: Racial, ethnic and gender disparities impact the real-world reproducibility of clinical trials leading to drug approvals for hematologic malignancies. Interestingly, a prior abstract (Boisclair et al., 2022) has shown an equitable enrollment between US demographic groups in frontline trials for newly-diagnosed non-Hodgkin lymphoma. Although disparities in multiple myeloma (MM) trial participation have been oftentimes demonstrated, prior studies (Kanapuru et al., 2022; Alqazaqi et al., 2022) predominantly involved patients with relapsed/refractory MM (RRMM). To further assess this gap, we conducted a cross-sectional analysis of US demographic representation in phase II or III trials for newly-diagnosed MM (NDMM). Methods: Clinicaltrials.gov was searched for completed NDMM trials with a recruitment period between 01/01/2007-12/31/2020. Studies limited to phase I data (n=10), enrolling <30 patients (n=35), including RRMM or other malignancies (n=18), and/or recruiting outside the US (n=93) were excluded. We subdivided patients according to gender, race, and ethnicity. For each subgroup, total new cases of MM from 2007-2020 were identified via the Surveillance, Epidemiology and End Results (SEER) Cancer Statistics Explorer Network, with subsequent calculation of a trial enrollment fraction (TEF; number of trial enrollees divided by incident US cases). Pearson's chi-square test was used to compare TEF between subgroups, yielding odds ratio (OR) and 95% confidence interval (95%CI) values, with P<0.05 deemed significant. Results: Among the 194 trials found on initial review, 25 met the established criteria for inclusion (Figure 1). All studies (n=3,559) described the participants' gender, while only 18 (72%; n=3,129) reported race and 9 (36%; n=2,319) reported ethnicity. Overall, women showed a significantly lower TEF compared to men (OR, 0.88; 95%CI, 0.82-0.94; P<0.001). When compared to White Americans, TEF was significantly lower for African Americans (OR, 0.71; 95%CI, 0.64-0.78; P<0.001) and Asian Americans/Pacific Islanders (AAPIs; OR, 0.64; 95%CI, 0.22-0.41; P<0.001). In studies reporting ethnicity, TEF was significantly lower for Hispanics compared to non-Hispanics (OR, 0.18; 95%CI, 0.14-0.24; P<0.001). Conclusion: Our cross-sectional analysis reveals an underrepresentation of women, African Americans, AAPIs, and Hispanics in NDMM trials conducted around the US. These findings are complementary to the enrollment disparities previously shown in RRMM trials. Through the implementation of a comprehensive diversity plan, MM trials must include a more inclusive representation of the US population affected by this blood cancer. Such an approach will not only enhance the external validity of these trials but also mitigate the impact of ascertainment bias and promote healthcare equity.

The Glass Wall: Gendered Authorship Disparities in in CD 19 and BCMA CAR-T Clinical Trials for Lymphoma and Myeloma

Introduction: Existing literature suggests that women are significantly underrepresented in the field of hematology-oncology. Data from 2021 suggests that women make up 35.6% of hematologists, and thus the disparity continues in clinical trial research authorship. Minorities including women receive fewer awards, deliver fewer board review lectures, and hold fewer professorships, and leadership positions in clinical departments and professional organizations. To further investigate this issue, we conducted a study to assess the gender gap in authorship across 13 pivotal clinical trials that led to the approval of CD19 and BCMA Chimeric antigen receptor T cell (CAR-T) therapies. Methods: We included the 13 pivotal trials that led to the approval of CART for Acute Lymphoblastic leukemia (ALL), lymphoma and myeloma , published between 2017-2022. These included the trials: ELIANA, ZUMA-1, JULIET, ZUMA-2, KarMMa, TRANSCEND, ZUMA-5, CARTITUDE-1, ZUMA-7, ZUMA-3, TRANSFORM, PILOT, and ELARA. We examined the overall number of female authors, the number of lead female authors as defined as first, second, or last author, and the ratio of all authors to female authors. 367 total authors were included in the analysis, with several authors being included more than once for their work on separate studies. Results: Table 1 summarizes the results. Of the 367 authors assessed, 109 were female, correlating to 28.9% female authorship. The only study with female authorship >50% was ELIANA, a 2017 pediatric study, while all others had >50% male authorship. 7 (54%) of the 13 studies had females as lead authors; of note, 6 out of 7 of these studies were published after 2021. Conclusion: Gender inequities in research authorship are pervasive in many areas of medicine, including the field of immune effector cell therapy. Publications in the field broadly are overwhelmingly male dominated, possibly reflective of lower female representation in transplant and cellular therapy. Despite this, we observed improved gender equality in authorship in more recent publications since 2021, and in certain research areas such as pediatric hematology-oncology. Recognizing these seemingly invisible barriers is the first step in bringing gender equity to the field of hematopoietic stem cell transplant and cellular therapy, with gender serving as one of many domains in which underrepresented groups' ability to scale the glass wall must be supported. Table 1.

The Presence of Bulky Disease and/or Very High LDH Defines a High-Risk Subset of IPI 1-2 for Eligibility in Clinical Trials of Newly Diagnosed Aggressive B-Cell Lymphoma

Background: The goal of clinical trial eligibility criteria is to identify a population of patients that have high risk disease or have unmet needs with standard of care therapy. Frontline trials of diffuse large B-cell lymphoma (DLBCL) include patients with International Prognostic Index (IPI) scores of 3-5 as a way to identify a high risk population. Trials typically include patients with IPI score=2, and sometimes IPI score=1, to expand the eligible patient population. However, broader patient populations must be balanced by the potential inclusion of low-risk patients with excellent outcomes to standard of care therapy, leading to potentially underpowered trials. IPI is a sum of dichotomous variables which makes implementation easy but can result in heterogeneity in outcomes within IPI scores. This heterogeneity may be caused by unequal prognostic information across IPI variables, loss of information within IPI variables due to the use of cutoffs, as well as information captured by variables that are not included in the IPI. In prior modeling of outcomes in DLBCL (Maurer et al, AJH 2016), we identified that: i) LDH has a strong prognostic ability beyond the upper limit of normal (ULN) and ii) bulky disease is an independent variable for prognosis. Here we evaluate if the presence of either of these two variables, easily captured at diagnosis within the current standard clinical work-up, can identify a high-risk subset of patients within the population of those with IPI scores of 1-2. Methods: Patients with newly diagnosed lymphoma were enrolled within 6 months of diagnosis in the LEO Cohort at 8 academic medical centers from 2015-2020 and prospectively followed. Inclusion criteria for this analysis was aggressive B-cell lymphoma typically included in frontline trials (e.g. DLBCL, high grade B-cell lymphoma, FL3B), IPI 1-5, frontline therapy with rituximab and anthracycline-based chemotherapy, stage II-IV disease and ages 18-80 years. Event-free survival (EFS) was defined as the time from diagnosis until progression, initiation of 2 nd line therapy, or death due to any cause; EFS was evaluated at 24 months (EFS24). Very high LDH was defined as LDH>1.3xULN based on prior modeling (Maurer et al, AJH 2016) and bulky disease was defined as maximum tumor diameter (MTD) of 7cm or greater. IPI 1 and 2 were first evaluated separately and then combined due to similar outcomes in patients with very high LDH and/or bulky disease. High risk IPI1-2 was defined as the presence of either bulky disease and/or very high LDH within an IPI score of 1-2. Confirmation was performed in a similar cohort of patients enrolled in the Iowa/Mayo SPORE Molecular Epidemiology Resource (MER) from 2002-2015; bulky disease was defined using a 10cm cutoff per availability in MER data collection forms. Results: 1560 patients from LEO were analyzed; median age was 64 years (IQR: 54-71), 42% were female and 83% had stage III/IV disease; subtype was DLBCL, NOS in 1335 (86%). IPI was 1-2 in 766 patients, 3 in 496 patients and 4-5 in 298 patients ( table). 391 (51%) with IPI1-2 had either bulky disease and/or very high LDH (high risk IPI1-2) and 375 had low-risk IPI1-2. EFS24 in high risk IPI1-2 (71.6%, 95% CI: 67.2-76.3) was significantly inferior to IPI1-2 without bulky disease or very high LDH (85.2, 95% CI: 81.7-88.9 logrank p=0.0035, figure) and similar to patients with IPI3 (70.7%, 95% CI: 66.8-74.9). Consistent results were observed in 1014 patients analyzed in the MER using a higher cutoff for bulky disease (10cm) due to data availability ( table). Patients with high risk IPI1-2 had significantly shorter diagnosis to treatment interval (DTI) in both the LEO (per-week OR=0.83, 95% CI: 0.77-0.88) and MER (per-week OR=0.77, 95% CI: 0.68-0.87) cohorts compared to low risk IPI1-2, both p<0.0001). In sensitivity analysis, LEO results were similar when performed in the subset of patients with DLBCL, NOS. Conclusion: The presence of either bulky disease and/or very high LDH at presentation identifies a high-risk subset of patients with IPI 1-2 that have similar outcomes to patients with IPI 3 disease. These simple criteria can be easily implemented within existing clinical trial diagnostic work-ups. Future trial designs in frontline aggressive B-cell lymphoma should include patients with IPI 3-5 and patients with IPI 1-2 with either bulky disease and/or very high LDH to better define a high-risk population of patients for clinical trial eligibility.

Obinutuzumab Versus Rituximab in Transplant Eligible Untreated MCL Patients, a Matching Comparison between the Lyma and Lyma-101 Trials

Aim: Obinutuzumab (O) and Rituximab (R) have never been compared in a prospective randomized trial in mantle cell lymphoma (MCL). The LYMA-101 trial (NCT02896582) investigated the Obinutuzumab-DHAP (O-DHAP) regimen followed by autologous stem cell transplant (O-BEAM, ASCT) plus O maintenance (OM) in transplant eligible patients <66y with untreated MCL (Le Gouill et al, Lancet Hem 2020). The LYMA trial (NCT00921414) used the same regimen with Rituximab instead of Obinutuzumab (Le Gouill et al, NEJM 2017). Herein, we report the long-term outcome of patients enrolled in the LYMA-101 trial and used a propensity score matching (PSM) approach to allow a comparison with patients treated in the LYMA trial (i.e. O versus R group matched comparison). Method: LYMA (n=299 pts, of whom 120 received R Maintenance, RM) is a phase III prospective trial with a median follow-up of 7.5 years (7.4-7.7) from inclusion (Sarkozy et al, ASCO 2023) that randomized, after ASCT, 240 pts between observation and RM. LYMA-101 (n=86) is a prospective single arm phase 2 trial with a median FU of 5.1y (5-5.25) at the time of the present analysis. We first compared minimal residual disease (MRD) at end of induction (EOI), assessed in both trial with quantitative PCR of clonal immunoglobulin gene and used PSM based on clinical characteristics at inclusion (Sex, Ann Arbor stage, MIPI score, B symptoms, blastoid variant, bulky disease) to balance patients' discrepancies between LYMA-101 and LYMA. To compare PFS and OS from inclusion of patients treated with R versus O based regimen, half of the non-randomized LYMA patients (29 out of 58) were randomly reattributed to the RM arm to create an intention to treat RM (RM-ITT) arm including 149 pts (29 non-randomized and 120 randomized) subsequently matched with the 86 LYMA-101 pts. Balance between populations was checked using standardized mean differences (SMD). Results: Eighty-five LYMA-101 pts received the first course of O-DHAP (1 withdrew consent before treatment), 81 (95.3%) completed the 4 cycles and 73 (85.9%) underwent ASCT followed by OM in 69 (81.2%). The estimated 5y PFS and OS since inclusion were 83.4% (95%CI: 73.5-89.8%) and 86.9% (95%CI: 77.6-92.5%) respectively. At EOI, ORR were similar in both studies (89.6% versus 91.8% in LYMA versus LYMA-101 respectively), but within responders, pts treated in LYMA-101 (O-DHAP) had a more frequent MRD negativity than pts treated in LYMA (R-DHAP) both in bone marrow (BM, 82.1% versus 65.3% MRD negativity in O vs R group, Chi2 p=0.011) and blood (95.5% versus 79.2% of MRD negativity in O vs R group, Chi2 p=0.002). These results were confirmed using the propensity score matched populations, with a more frequent MRD negativity in the O versus R group in BM (82.1% vs 63.4%, Chi-2, p=0.01) and blood (95.5% vs 72.9%, Chi-2, p<0.001). To compare PFS and OS since induction, a PSM was performed using the 149 patients treated in the R-group with an RM-ITT and the 85 patients in the O group, resulting in 2 sets of 82 patients with comparable characteristics at inclusion. From treatment initiation, patients treated with O presented a prolonged PFS (p=0.029, figure 1A) and OS (p=0.039, figure 1B) compared to those treated with R, with an estimated 5-year PFS of 82.8% versus 66.6% (HR 1.99, IC95 1.05-3.76) and OS of 86.4% versus 71.4% (HR 2.08, IC95 1.01-4.16) with O and R based regimen respectively. Finally, 37/120 (30.8%) patients in LYMA and 23/69 (33.3%) in LYMA-101 prematurely stopped R and OM respectively (with a similar mean maintenance duration of 29 and 29.4m with R and OM respectively). Reason for maintenance discontinuation were adverse events in 15 cases in R group (12.5% of the population) versus 14 cases in O group (20% of the population), progression or death in 10 (8.3%) versus 3 (4.3%) cases in the R versus O group respectively. Causes of death were comparable in O and R groups, the most common being lymphoma (42% in O and 53% in R group). Infectious deaths in the O group (N=3) were all COVID related (3/12 deaths, 25%), whereas in the R group (LYMA being conducted before the pandemic), 8 deaths were related to infection (8/97 deaths, 8%, including 1 infectious death out of 22 deaths during RM, 5%). Conclusion: O-DHAP followed by OM post ASCT provide prolonged PFS and OS in young patients with MCL. O-based therapy in MCL induce deeper response with increased MRD negativity and seems to outperform R-based therapy in term of PFS and OS, without any significant excess of toxicity.