Citations

476 Background: Outcomes remain poor for patients with advanced/metastatic CCA treated with first-line gemcitabine-cisplatin +/- anti-PD(L)1. Lirafugratinib is the first highly selective, irreversible FGFR2 inhibitor designed to target oncogenic FGFR2 driver alterations and resistance mutations. ReFocus (NCT04526106) is an open-label, multicenter phase 1/2 study in patients with advanced/metastatic CCA and other solid tumors with FGFRok2 alterations. Methods: Pivotal cohort of patients (n=116) with advanced/metastatic CCA harboring FGFR2 f/r previously treated with ≥1 systemic therapy and FGFR i-naive were treated with oral lirafugratinib 70 mg once daily until disease progression or unacceptable toxicity. The primary endpoint was confirmed ORR per RECIST v1.1 by independent review committee (IRC). Key secondary endpoint was duration of response (DOR); other secondary endpoints: disease control rate (DCR), progression-free survival (PFS), overall survival (OS), safety, and quality of life per EORTC QLC-C30. Results: As of 27SEP2024, the primary efficacy analysis of IRC-assessed data (n=114) and the secondary analysis of investigator-assessed data (n=116) set was done. The primary efficacy analysis excluded 2 patients as not available. Median age 57 years with 61.4% female. IRC-assessed ORR was 47%, and median DOR was 11.8 months (mos) (95% CI, 7.5-13.0), where 76.2% of responses lasted >6 mos. Median PFS was 11.3 mos (95% CI, 9.2, 14.8), with 12-month rate of 49.2%. Median OS was 22.8 mos (95% CI, 17.3-27.2), with 12-month rate of 74.6%. DCR was 96.5%. Common grade ≥3 on-target, off-tumor treatment-related adverse events (TRAEs) included palmar-plantar erythrodysesthesia (32.8%) and stomatitis (12.1%). TRAEs led to dose reductions of 75.9%, dose interruption of 82.8%, and treatment discontinuation of 4.3%. QoL was maintained. Conclusions: Lirafugratinib demonstrated clinically meaningful anti-tumor activity (ORR, DOR, and PFS), manageable and tolerable safety in CCA FGFR2 f/r patients. Clinical trial information: NCT04526106 . Best Overall Response, n (%) IRC c Investigator d Complete Response Partial Response Stable Disease Progression Disease Not Evaluable 3 (2.6)50 (43.9)57 (50.0)3 (2.6)1 (0.9) 061 (52.6)51 (44.0)3 (2.6)1 (0.9) ORR a , n (%)95% CI 53 (46.5)37.1, 56.1 61 (52.6)43.1, 61.9 DCR b , n (%)95% CI 110 (96.5)91.3, 99.0 112 (96.6)91.4, 99.1 a ORR defined as proportion achieving confirmed response of complete response or partial response per RECIST v1.1. b DCR defined as proportion with confirmed response of complete response, partial response, or stable disease per RECIST v1.1. c Primary Efficacy Analysis Set. d Secondary Efficacy Analysis Set. Percentages based on number of patients in the analysis set for each treatment arm. Exact Clopper-Pearson used for 95% CI. IRC and investigator assessments are based on different populations and cannot compare directly.

Abstract Delirium is a state of acute confusion characterized by deficits in attention that occurs commonly in hospitalized older adults and is associated with adverse outcomes. Delirium may have significant implications for cognitive health, however the relationship of delirium to mild cognitive impairment (MCI) and dementia is not fully understood. To evaluate the impact of delirium on cognitive health trajectories, we leveraged the Mayo Clinic Study of Aging (MCSA), a population-based cohort study of cognitive health and aging in residents of Olmsted County, Minnesota, who are between the ages of 30 and 89 and without a previous diagnosis of dementia at enrollment. Emergency Department and hospital encounters were identified for all patients enrolled in the MCSA, and clinical notes following each encounter up to 30 days were analyzed using a previously validated natural language processing (NLP) algorithm for delirium detection. The association between delirium within 30 days of hospitalization and the development of MCI or dementia was assessed using Cox proportional hazards regression, adjusted for patient age, sex, and level of education. Initial MCSA assessment indicated normal cognition for all individuals in this cohort. We found that delirium was significantly associated with development of MCI and dementia, with 42 individuals experiencing delirium within 30 days of hospitalization; hazard ratio of 10.07 (95% CI 4.14, 24.49) for developing MCI and 19.10 (95% CI 8.40, 43.47) for dementia compared to those without delirium. Our results suggest that hospitalization with an episode of delirium can significantly impact cognitive trajectories in older adults.

Background/Objectives: The purpose of this study is to assess whether the addition of an oxymetazoline (OXY) hemostatic solution, which can be used to manage pulpal bleeding, maintains higher MTA survivability than pulpotomies treated with FS. Methods: In this retrospective cross-sectional study, patient data (n = 75) were used to assess radiographic and clinical signs and symptoms of pathosis in primary molars treated with a pulpotomy and a stainless-steel crown. Pulpotomies treated with FS (Group 1) were compared to those treated with MTA with OXY-induced hemostasis (Group 2). Restricted mean survival times (RMSTs) were calculated for the two groups, and Cox proportional hazards regression was used to analyze the effects of patient and practice level covariates on radiographic and clinical pathosis. Results: Cox proportional-hazard regression identified three potential covariates (age, pulpotomy groups, and procedure location) that predicted radiographic pathosis. The adjusted hazard ratio for Group 2 was 0.30 (95% CI: 0.11–0.82), indicating improved radiographic outcomes compared with Group 1 (p = 0.02). The 36-month RMST for Group 2 was 30.1 months (95% CI: 26.5–33.7) compared to 24.7 months (21.6–27.8) for Group 1 (p = 0.025). Conclusions: A pulpotomy utilizing OXY hemostasis prior to MTA placement led to a higher chance of pulpotomy survival than FS.

Abstract The benefit of rituximab maintenance after first-line (1L) bendamustine-rituximab (BR) in patients with mantle cell lymphoma (MCL) remains uncertain, with inconsistent results from the phase 2 MAINTAIN trial and several retrospective studies. We conducted a large retrospective study at 27 US and Canadian academic centers to examine the benefit of rituximab maintenance after BR. A total of 911 patients received 1L BR between 2010 and 2020, and 703 had an objective response and no evidence of disease progression at the 3-month post-BR landmark. Among those, 394 (56%) received rituximab maintenance and 309 (44%) did not, with largely similar baseline patient and disease characteristics. In the landmark analysis, rituximab maintenance was associated with improved event-free survival (EFS; median, 49.9 vs 29.7 months; P< .001) as well as overall survival (OS; median, 109.5 vs 74.2 months; P< .001). The EFS and OS benefits were observed across most of the subgroups. EFS and OS differences were statistically significant in those who achieved a complete response to 1L BR (n = 590; median EFS, 62.7 vs 31.1 months [P< .001]; median OS, 136.1 vs 75.3 months [P< .001]), but the analysis among those who achieved a partial response to 1L BR was limited by the small sample size. These results provide additional evidence for the survival benefit of rituximab maintenance after BR in MCL and support its use in clinical trial design and routine practice.

Abstract This study delineates a novel multisystem caliber-persistent arteriopathy syndrome, fundamentally redefining the classical Dieulafoy's lesion from a localized gastrointestinal anomaly to a systemic congenital vasculopathy. Through integrated histopathological and genomic analysis of a forensic autopsy case, we identified pervasive arterial remodeling across seven organ systems— characterized by absent physiological tapering— indicating developmental angiogenic dysregulation. Whole-genome sequencing uncovered pathogenic variants in PDE8B , LRCH1 , and ADA genes, with functional enrichment analyses implicating dysregulated purine–cAMP signaling and cytoskeletal organization as core pathogenic mechanisms. These findings establish a genetic basis for the observed pan-vascular phenotype and highlight the necessity of systematic vascular screening in cases of unexplained multiorgan hemorrhage. This work provides a foundational framework for diagnosing and investigating congenital vascular malformations with hemorrhagic risk, urging a paradigm shift in clinical evaluation and etiological assessment.

Abstract Introduction: CTCLs are rare, heterogeneous non-Hodgkin lymphomas (NHL) with significant regional variability in treatment patterns. Prospective studies characterizing CTCL management, particularly in racially and ethnically diverse populations, remains limited. The LEO-MER multi-center prospective cohort study (NCT02736357) is designed to address the persistent disparities in outcomes research by enrolling historically underrepresented groups of patients diagnosed with lymphoma across the United States (US). Here, we present a real-world analysis of CTCL patients that reflects US academic practice, evaluating treatment patterns, as well as prognostic factors influencing survival outcomes. Methods: Patients aged ≥18 years with newly diagnosed CTCL were prospectively enrolled in either the University of Iowa/Mayo Clinic MER cohort (2002-2015) or the expanded LEO cohort (2015-2020), which included 8 US academic centers. Standardized protocols were used to abstract clinical, pathologic, treatment, and outcome data from medical records. ANOVA/Kruskal-Wallis and Fisher's/chi-square tests were used to compare patient distribution across demographic and clinical characteristics based on data distribution and sample size. Overall survival (OS) was calculated from diagnosis to death or last follow-up. Survival analyses employed Kaplan-Meier estimation supplemented by Cox proportional hazards modeling. Results: The LEO-MER cohort enrolled 223 CTCL patients (91 MER and 132 LEO). Subtypes included mycosis fungoides (MF, n=155, 69.5%), Sézary syndrome (SS, n=22, 9.9%), primary cutaneous anaplastic large-cell lymphoma (n=17, 7.6%), subcutaneous panniculitis-like T-cell lymphoma (n=11, 4.9%), cutaneous CD4+ small/medium T-cell lymphoproliferative-disorder (n=9, 4%), and other rarer CTCL subtypes (n=9, 4%). Among the MF/SS cohort, median age was 64 years (Range: 18-89 years), 58.2% (n=103) were male and race/ethnicity distribution included White (n=123, 69.5%), Black (n=29; 16.4%) and others/unknown (n=25; 14.1%). Stage distribution included 62.7% with early-stage (ES) MF (IA-IIA, n=111), 37.2% with advanced-stage (AS) MF (IIB-IVB, n=66). To complete diagnostic workup, T-cell receptor (TCR) testing was performed in 52.6% of skin biopsies (n=92) and 62.5% of blood samples (n=110), with clonal detection rates of 75% (69/92) in skin and 51.8% (57/110) in blood. Paired TCR matching between skin and blood samples was performed in 31.6% (n=56) of cases, demonstrating 53.6% (30/56) concordance. Blood flow cytometry data were reported in 80.1% (89/111) and 84.4% (56/66) of ES and AS MF cases, with T-cell population being detected in 7.2% (8/111) and 62.1% (41/66) of ES and AS cases. Nodal biopsies were obtained in 23.4% (n=41) of patients and clonality assessment was reported in 18.6% (33/177) of these cases. The MF/SS cohort's lifetime treatment exposure data (n=160) revealed topical skin-directed therapies alone (n=49, 31.8%) as the most common approach followed by lifetime exposure to topical skin-directed and systemic therapies (n=45, 29.2%) followed by multimodal exposure of topical skin-directed, radiation and systemic treatments (n=30, 19.5%). Only 5.6% of patients were enrolled in a clinical trial. First-line (1L) systemic regimens were predominantly a) immunomodulatory agents (n=47, 29.3%); including oral retinoid (n=20), extracorporeal photopheresis (n=18), interferon (n=9) followed by b) chemotherapy (n=30, 18.7%) and c) targeted therapies (n=17, 10.6%) including Brentuximab Vedotin (n=6), Romidepsin (n=5), Mogamulizumab (n=3), Vorinostat (n=2) and Pralatrexate (n=1). Multivariable analysis predicting 1L systemic treatment initiation demonstrated a significant association with presence of N2/N3 stage (N2/N3 vs N0/N1: Odds Ratio (OR): 5.45) and elevated LDH (OR: 5.30). At median follow-up of 91.1 months (mon), median OS was 122.3 mon (95% confidence interval 67.2-159.2 mon). In subset analyses, Black race (p=0.001) and SS (p=0.0001) were associated with worse OS outcomes. Conclusion: We present initial data from our prospective LEO-MER cohort, a large US-based multicenter consortia. Our findings demonstrate variability in both diagnostic staging and treatment approaches for MF/SS patients. The cohort demonstrated worse outcomes with high-risk disease and Black race/ethnicity. These findings warrant further study on the impact of underlying social determinant factors, given the variability noted in this population.

Abstract Introduction Chimeric antigen receptor (CAR) T-cell therapies have revolutionized the treatment of relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL), with axicabtagene ciloleucel (axi-cel) and tisagenlecleucel (tisa-cel) both being approved for use. Axi-cel was approved for second-line setting based on studies showing improved outcomes compared to high-dose salvage chemoimmunotherapy followed by autologous hematopoietic stem cell transplantation (HSCT). In contrast, tisa-cel did not demonstrate superiority over traditional salvage therapies in the second-line setting. Although both therapies are currently used in clinical practice, real-world comparative data on the safety of axi-cel versus tisa-cel remain limited. This retrospective study aims to compare the one-year outcomes of axi-cel and tisa-cel in patients with R/R DLBCL, offering practical insights into their outcomes outside of clinical trial settings. Methods A retrospective cohort study was conducted using TriNetX, a global federated health research network that provides access to electronic medical records from approximately 132 million patients, primarily in the United States. Adult patients (≥18 years) diagnosed with R/R DLBCL between January 1, 2022, and January 1, 2024, were identified using ICD-10-CM codes. Patients were categorized into two cohorts: those who received axi-cel and those who received tisa-cel. Propensity score matching (1:1) using nearest neighbor matching with a 0.1 pooled standard deviation caliper was performed for demographics, comorbidities, prior stem cell transplantation, and medications. Study outcomes included 1-year rates of all-cause mortality, all-cause hospitalization, cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), anemia, neutropenia, thrombocytopenia, heart failure exacerbation, and acute myocardial infarction. Statistical analyses were conducted on the TriNetX platform, with significance set at P<0.05 (two-sided). TriNetX calculates hazard ratios (HRs) and cumulative incidences (CIs) using R survival package version 3.2-3 with the proportional hazard assumption tested using Schoenfeld residuals. This study does not require Institutional Review Board review or informed consent due to the use of de-identified data. Results Our study identified 1,250 patients with R/R DLBCL, including 1,083 patients who received axi-cel and 167 who received tisa-cel. After propensity score matching (PSM), 160 patients were in the axi-cel group (mean age 61.7 ± 11.8 years; 38.8% female; 73.1% White, 8.1% African American) and 160 patients were in the tisa-cel group (mean age 62.3 ± 16.0 years of age; 39.4% female; 75.0% White, 7.5% African American). Axi-cel group had 45% lower risk of all-cause mortality compared to tisa-cel group (HR: 0.55; 95% CI: 0.34–0.87). However, axi-cel group was associated with higher risks of all-cause hospitalization (HR: 1.33; 95% CI: 1.04–1.70), CRS (HR: 2.19; 95% CI: 1.43–3.36), and ICANS (HR: 2.69; 95% CI: 1.42–5.11) compared to tisa-cell group. No significant differences were observed in anemia (HR: 1.18; 95% CI: 0.82–1.72), neutropenia (HR: 1.30; 95% CI: 0.96–1.77), and thrombocytopenia (HR: 0.96; 95% CI: 0.65–1.43) between these two treatment groups. Additionally, there were no significant differences in terms of septic shock (HR: 0.79; 95% CI: 0.42–1.47), pneumonia (HR: 0.64; 95% CI: 0.34–1.21), and heart failure exacerbation (HR: 1.16; 95% CI: 0.76–1.76) between axi-cel group and tisa-cell group. Conclusion This large and multicenter cohort study provides real-world valuable insights into the one-year comparative outcomes of axi-cel and tisa-cel in patients with R/R DLBCL. Our study suggested axi-cel was associated with lower mortality rate, despites its higher rates of all-cause hospitalization, CRS, and ICANS compared to tisa-cell. These findings highlight the importance of close monitoring and supportive care during the first year following CAR-T therapy to optimize patient outcomes. An important limitation of our study is the lack of data on the number of prior lines of therapy, which may have differed between treatment groups and could have influenced clinical outcomes. Future prospective studies with comprehensive clinical data and inclusion of lisocabtagene maraleucel (liso-cel) would be valuable to provide a more complete comparison across currently available CAR T-cell therapies.

Abstract Background Nodal peripheral T-cell lymphomas (nPTCLs) are a challenging group of non-Hodgkin lymphomas that frequently recur after or are refractory to first line (1L) treatment. Chemotherapy options in the relapsed or refractory (R/R) setting are limited. The incorporation of non-cytotoxic agents including antibody drug conjugates, immune checkpoint inhibitors, epigenetic modifiers, and phosphatidylinositol 3-kinase inhibitors offers new therapeutic potential and possibly better outcomes. We report on outcomes for patients (pts) with R/R nPTCL enrolled in the multi-center LEO-MER prospective cohort study (NCT02736357) who received second line (2L) therapy. Methods Six hundred and three adult pts with newly diagnosed nPTCL were prospectively enrolled in the University of Iowa/Mayo Clinic MER observational cohort (2002-2015) or the expanded LEO cohort (2015-2020). Secondary overall survival (sOS) was calculated from date of 2L treatment initiation to date of death or last follow-up. Secondary event-free survival (sEFS) was calculated from date of 2Ltreatment initiation to disease progression, initiation of 3rd line therapy, or death from any cause. sEFS and sOS were evaluated using Cox model and Kaplan-Meier estimator. Log-rank test was used to test the significance of difference between groups. Pts with concomitant B-cell lymphomas were excluded from this analysis. Results Thus far, 169 pts with nPTCL initiating 2L therapy were evaluated. Of these, 75 (44.4%) had PTCL-NOS, 63 (37.3%) had angioimmunoblastic T-cell lymphoma (AITL, inclusive of nodal T-follicular helper cell lymphoma), 20 (11.8%) had ALK-negative anaplastic large cell lymphoma (ALCL), and 11 (6.5%) had ALK-positive ALCL. At 2L treatment initiation, the median age was 64 with 86.1% of pts having advanced stage disease. Of the 108 pts with available international prognostic index (IPI) scoring, 46.3% had an IPI of ≥3. Thirty-four (20.1%) pts had received a consolidative autologous stem cell transplant (ASCT) in the 1L. A total of 86 pts (50.1%) had primary refractory disease (partial response, stable or progressive disease as best response to 1L therapy), 45 (26.6%) experienced early relapsing disease within 6 months of 1L therapy, and 38 (22.5%) had relapsed disease >6 months from 1L therapy. After a median follow-up of 7.1 years (yrs), median sOS was 1.52 yrs, and sEFS was 3.2 months (mos). There was no difference in sOS or sEFS regardless of timing of relapse. In keeping with other studies, ALK-positive ALCL pts had the best 5-year OS (70.1%) compared to other subgroups (ALK-negative ALCL 45.0%, AITL 30.4%; PTCL-NOS 21.3%). Lymphoma was the leading cause of death following 2L therapy, with a 2-year cumulative incidence of 49.2%. Eighty pts (47.3%) received only cytotoxic chemotherapy as second line (2L) therapy; ICE (41 (51.3%)) and gemcitabine-containing regimens were most common (14 (17.5%)). Seventy-five pts (44.4%) were treated with non-cytotoxic agents given as monotherapy or in combination with chemotherapy. The most common non-cytotoxic therapies were brentuximab vedotin (33 (44.0%)), romidepsin (17 (22.7%)) and immune checkpoint inhibitors (9 (12.0%)). Fourteen pts (8.3%) underwent palliative interventions involving radiation, steroids, or cyclosporine alone. Intent to proceed to transplant in the 2L was known in 158 pts (101 (63.9%) not intended, 57 (36.1% intended)). Following 2L treatment, 18 (10.7%) pts proceeded to consolidative ASCT and 10 (5.9%) to allogeneic transplant. Only 21 (12.9%) were treated on a clinical trial. Pts who received a non-cytotoxic agent had superior outcomes compared to pts receiving only chemotherapy; the median sOS was 30.4 mos (95% confidence interval [CI] 15.3, 53.52 mos) vs 11.7 mos ((95% CI 7.95,19.58); p=0.04; HR 0.67) and the median sEFS was 4.83 mos (95% CI 3.38, 10.09) vs 2.33 mos ((95% CI 1.71,3.02); p=0.02; HR=0.65). Conclusions We report here one of the largest prospective cohorts in R/R nPTCL. The LEO-MER cohort, despite its association with academic centers, shows poor outcomes regardless of refractory or relapsed disease, frequent inability to proceed to intended consolidative transplant, and low clinical trial participation in 2L, which corroborates findings from other registries (Jain 2025, Stuver 2019). Outcomes improved for pts treated with non-cytotoxic agents. Updated data including additional pts and subgroup analyses will be reported at the meeting.

Abstract PAX5 is genetically altered in over 30% of B-ALL cases, with point mutations representing the second most common type of alteration. These point mutations are highly enriched in the DNA binding (paired) domain and have been recognized as founder events in PAX5 P80R and PAX5alt B-ALL subtypes, which account for over 12% of B-ALL. However, the molecular features and underlying mechanisms of these mutations in B-ALL remain largely undefined, limiting the development of targeted therapies and resulting in poor outcomes, especially in adult patients. We systematically investigated the functional roles and oncogenic mechanisms of PAX5 paired domain mutations. Integrated CRISPR screening and genomic profiling revealed that the paired domain is critical for PAX5 function. Disruptions in this region significantly reduced cell viability in B-ALL cell lines, and analysis of 2,955 B-ALL samples showed that recurrent PAX5 missense mutations are highly enriched in this domain, further underscoring its functional importance. Functional analysis of knock-in mice with PAX5 mutations revealed that R38H and R140L severely impair DNA binding and block B-cell differentiation, while P34L and P80R retain binding ability but alter binding specificity and gene regulation. Mice carrying homozygous (P34L, R38H, P80R, R140L) or heterozygous (R38H, P80R) mutations developed spontaneous B-ALL within one year. To model co-occurring mutations observed in patients, Pax5 R38H/P34L and R38H/R140L mice were generated. These compound mutations exhibited greater leukemogenic potential than single mutants. Transcriptomic analysis of leukemia samples showed consistent up-regulation of metabolic pathways and Myc target genes. Notably, biallelic PAX5 alterations and additional genetic lesions in signaling pathways were detected in all PAX5R38H/+ and PAX5P80R/+ leukemias, faithfully recapitulating the genetic alteration features of patient B-ALL driven by PAX5 mutations. Among Pax5-mutant mouse strains, Pax5P80R/+ mice develop B-ALL with short latency and complete penetrance, making them an ideal model to study the mutational evolution and leukemogenesis of B-ALL. To characterize the stepwise leukemogenesis process, we performed serial bone marrow aspirations in the same Pax5P80R/+ mice. In all 17 mice analyzed, we identified early preleukemic clones with only Pax5 WT deletions, followed by the emergence of leukemic clones harboring Jak1/3 mutations. Single-cell RNA/BCR-seq revealed that Pax5 WT allele deletions relieve metabolic constraints, thereby promoting clonal expansion of preleukemic B cells blocked at the pre-B stage. These changes coincide with downregulation of metabolic checkpoint genes and upregulation of glycolytic enzymes, promoting genetic instability and facilitating malignant transformation. Clinically, PAX5 P80R patients have better outcomes than PAX5alt cases. Using our mouse models, we observed that leukemic cells driven by the PAX5 P80R mutation exhibit greater sensitivity to dexamethasone compared to the ones carrying other PAX5 mutations in PAX5alt subtype, potentially due to their heightened dependence on glucose uptake and glycolysis, suggesting that metabolic rewiring driven by PAX5 mutants may influence therapeutic response. Interestingly, we found that an aberrant isoform of MEGF10 (aMEGF10) is highly and specifically expressed in PAX5 P80R B-ALL. This N-terminal truncated isoform encodes a protein that retains the intracellular immunoreceptor tyrosine-based activation motifs (ITAMs). Using CUT&Tag, we showed that PAX5 P80R directly binds to the aMEGF10 promoter. By engineering human CD34⁺ cells, we established a humanized PAX5 P80R leukemia model that recapitulates the gene expression profile of patient samples, including robust activation of aMEGF10. Functionally, aMEGF10 binds to and activates SYK, thereby promoting leukemic cell proliferation. Importantly, this oncogenic effect depends on intact ITAM motifs and SYK signaling, revealing a novel targetable vulnerability in PAX5 P80R leukemias. Overall, the study establishes that PAX5 DNA binding domain mutations contribute to leukemogenesis through stepwise loss of PAX5 WT alleles and acquisition of signaling pathway mutations, involving impaired differentiation, metabolic deregulation, and novel oncogene activation. These findings not only deepen the understanding of PAX5-driven leukemias but also highlight aMEGF10–SYK signaling as a promising therapeutic target.

Abstract Background Previous studies in aggressive B-cell lymphoma demonstrate that patients with shorter diagnosis-to-treatment intervals (DTI) represent those with higher risk disease. This suggests that patients enrolled in clinical trials may carry a selection bias as they often have longer DTI than patients in the general population. This has important implications for clinical research design and the generalizability of clinical trials in aggressive lymphomas. However, the prognostic implications of DTI have not been evaluated in peripheral T-cell lymphomas (PTCL). Therefore, we examined DTI and its association with clinical factors and outcomes in a prospective observational cohort of patients with PTCL from the United States within the LEO (Lymphoma Epidemiology and Outcomes) and MER (University of Iowa and Mayo Clinic Specialized Programs of Research Excellence Molecular Epidemiology Resource). Patients and Methods We evaluated patients enrolled to the MER (2002-2015) and LEO (2015-2020) cohorts with the following forms of PTCL: PTCL-not otherwise specified (PTCL-NOS, n=217), nodal T-follicular helper (TFH) cell lymphoma (nTFHL, n=153), anaplastic large cell lymphoma (ALCL), ALK positive (ALCL, ALK+, n=74), ALCL, ALK negative (ALCL, ALK-, n=95), enteropathy associated T-cell lymphoma (n=18), and monomorphic epitheliotropic intestinal T-cell lymphoma (n=2). Associations of DTI with clinical factors and outcomes were examined using Kaplan Meier and Cox models. Event free survival (EFS) was defined as the time from start of treatment to relapse/progression, start of 2nd line therapy, or death from any cause. Overall survival (OS) was defined as the time from start of treatment until death from any cause. DTI was defined as the number of days between the first diagnostic biopsy and the start of therapy. Patients who were initially observed or had DTI > 100 days were excluded. Results In 559 patients (229 MER and 330 LEO), median age was 60, 34% had IPI>2 and 71% were stage III/IV. 472 (84%) patients initially received anthracycline-based chemotherapy. Median DTI was 23 days (interquartile range (IQR): 12-39) and was similar in MER (21 days, IQR: 11-33) and LEO (25 days, IQR: 14-42). 168 (30%) patients had DTI 0-14 days, 178 (32%) 15-28 days, and 213 (38%) 29-100 days. Overall in the cohort, shorter DTI was associated with a worse 5-year OS (DTI 0-14 days: 43%; DTI 15-28 days: 53%; DTI 29-100 days: 58%, p<0.001) and 5-year EFS (DTI 0-14 days: 31%; DTI 15-28 days: 39%; DTI 29-100 days: 45%, p<0.001). In multivariable analyses, the association of DTI with outcomes remained consistent after adjusting for age and International Prognostic Index (IPI). Shorter DTI was strongly associated with adverse clinical factors, including elevated lactate dehydrogenase levels, poor performance status, B-symptoms, and higher IPI in both cohorts (all P < .003). DTI was not associated with age, sex, or distance from the LEO/MER center (all p>0.3). 6% patients with DTI of 0-14 days received 1L treatment on a clinical trial, compared to 11% with DTI 15-28 days and 13% with DTI 29-100 days, underscoring that patients with lower DTI may be underrepresented in clinical trials. When examining within PTCL subtypes, the association between short DTI (0-14 days) and inferior outcomes was most prominent in PTCL, NOS (OS HR=2.13, 95% CI: 1.52-2.94; EFS HR =1.49, 95% CI: 1.19-1.85). Associations between short DTI and outcomes were weaker in other subtypes: nTFHL (OS HR=1.28, 95% CI: 0.83-2.00; EFS HR =1.22, 95% CI: 0.82-1.81), ALCL, ALK-, (OS HR=1.30, 95% CI: 0.59-2.86; EFS HR =1.32, 95% CI: 0.68-2.56), ALCL, ALK+, (OS HR=1.05, 95% CI: 0.26-4.17; EFS HR =2.12, 95% CI: 0.84-5.26). Conclusion Shorter DTI is associated adverse prognostic clinical factors (LDH, stage, high IPI) and inferior EFS and OS in newly diagnosed PTCL. Patients with DTI ≤ 14 days, which represents approximately 1/3 patients with PTCL, may be underrepresented in clinical trials. Understanding of this selection bias should inform clinical trial design and interpretation. Future studies should consider strategies to minimize barriers to enrollment for patients with low DTI.