Citations

Abstract Description Evidence consistent with immunoediting in human cancer has been identified through associative studies. To provide direct evidence that differences in the neoantigen profile are immune-mediated, we compared the neoantigen profiles of cutaneous squamous cell carcinoma (cSCC) from immunocompetent and immunosuppressed patients. Despite consistency in the overall mutational burden and signature, immunocompetent patients have a lower clonal mutational burden compared to immunosuppressed patients. Furthermore, clonal mutations in cSCC from immunocompetent patients have a lower proportion of neoantigens predicted to bind MHC class I, supporting the role of the immune system in shaping the neoantigen profile. In single-cell RNA sequencing of intratumoral CD8+ T cells from a separate cohort of cSCC from immunocompetent and immunosuppressed patients, we observe an increase in exhausted CD8+ T cells in tumors from immunocompetent patients, suggesting an explanation for the persistence of binding neoantigens subclonally. Finally, we compare clonal and subclonal neoantigens as an unbiased screen for characteristics associated with neoantigen immunogenicity. Neoantigens with a large increase in predicted MHC class I binding relative to the normal peptide are enriched in subclonal neoantigens in immunocompetent patients. Overall, this work supports the immune system’s role in sculpting the neoantigen profile of cSCC. Funding Sources Supported by American Cancer Society - Simone Charitable Foundation - Discovery Boost Grant, AZ-DBG-23-1151311-01-IBCD; NIH F30CA281056; R35GM149235 Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)

Abstract Disclosure: L. Miller-Wilson: Employee of Immunovant, Inc. N. Princic: Employee of Merative. K. Evans: Employee of Merative. N. Atreja: Employee of Immunovant, Inc. K. Tollefsen: Employee of Immunovant, Inc.. D. Toro-Tobón: None. Objectives: Graves’ disease (GD) is an autoimmune condition responsible for most cases of hyperthyroidism in the United States. An estimated 20%-50% of patients with GD will also develop thyroid eye disease (TED). Current treatments for GD focus on managing hyperthyroidism, but frequent monitoring, dose adjustments, and the high rate of relapse after discontinuation of antithyroid drugs can increase treatment costs and complicate long-term management. This study describes healthcare resource utilization (HCRU) and costs among patients with GD, with and without TED. Methods: This retrospective analysis utilized claims data from the Merative™ MarketScan® Research Databases. Individuals aged ≥18 years with ≥2 claims for a GD diagnosis from January 1, 2017-December 31, 2023 were included (first claim = index). To ensure a newly diagnosed cohort, patients with a history of GD-specific treatment or a GD diagnosis in the 12 months preceding the index were excluded. The final GD cohort was stratified into patients who had evidence of TED at any time during the 12-month pre-index period through 90 days post-index, and those who did not. Propensity score matching was used to balance patients with GD (with and without TED) with non-GD controls (1:3) on demographic and baseline clinical characteristics. Both GD cases (with and without TED) and controls were required to have ≥12 months of post-index follow-up. HCRU and costs were compared between cases and controls during a fixed 12-month post-index period. Categorical outcomes were compared using chi-squared tests, while continuous endpoints were compared using paired t-tests. Results: The analysis included 1,767 GD cases with TED matched with 5,301 controls (mean age, 53.1 years [standardized mean difference (SMD), 0.00]; 77% female [SMD, 0.00]; mean Charlson comorbidity score, 0.9 [SMD, 0.02]) and 43,120 GD cases without TED matched with 129,360 controls (mean age, 49.8 years [SMD, 0.00]; 78% female [SMD, 0.00]; mean Charlson comorbidity score, 0.7 [SMD, 0.01]). Compared with matched controls, patients with GD and TED had 78% more inpatient visits (0.16 vs 0.09), 104% more outpatient visits (65.06 vs 31.86), and 43% more prescriptions (30.21 vs 21.13) during the 12-month post-index period, while patients with GD without TED had 75% more inpatient visits (0.14 vs 0.08), 83% more outpatient visits (52.15 vs 28.48), and 38% more prescriptions (24.27 vs 17.56) (p<0.001 for all). Annual mean healthcare costs were 305% higher ($56,584 vs. $13,981) among GD patients with TED and 65% higher ($19,913 vs $12,076) in those without TED compared with matched controls. Conclusion: Patients with GD had significantly higher HCRU and healthcare costs than matched controls in the 12 months following diagnosis, and this difference was notably greater among GD patients who also had TED. More effective treatments are needed to address the health and financial burden of GD. Presentation: Monday, July 14, 2025

Background Challenges in predicting which neoantigens mediate tumor rejection limit the efficacy of neoantigen vaccines to treat cancers, especially for cancers with a high mutational burden like cutaneous squamous cell carcinoma (cSCC). Only a small portion of neoantigens prioritized by current methods elicit effective T cell responses, demonstrating the critical need for improved criteria for the prediction of tumor-rejecting neoantigens. Methods Publicly available human cSCC datasets were used to assess the frequency of shared mutations between patients. A transplantable ultraviolet light-induced mouse model of cSCC was generated. The mutational signature and driver mutations in the mouse model were compared with human tumors. Neoantigens were prioritized in the mouse model, and tumor-rejecting neoantigens were identified through (enzyme-linked immunosorbent spot (ELISpot) and in vivo prophylactic vaccination. Binding of the neoantigens and corresponding wild-type peptides to major histocompatibility complex (MHC) class I was determined. Structural modeling of peptide:MHC complexes was performed to assess for changes in structural characteristics of the neoantigens relative to the wild-type peptides. Results A minority of human cSCC tumors shared neoantigens. The mouse cSCC model recapitulated the mutational signature and driver mutations found in human disease and was constrained by CD8 T cells. Two MHC class I neoantigens were identified in the mouse model that constrained cSCC growth. One tumor-rejecting neoantigen exhibited improved MHC binding, and the other had increased solvent accessibility of the mutated residue, compared with wild-type. Across known neoantigens that do not impact MHC binding, increased exposure of the mutated residue distinguished tumor-rejecting from non-immunogenic neoantigens. Conclusions Given the paucity of shared mutations, this work supports the need for personalized neoantigen vaccines in cSCC. To facilitate further discovery, we provide a clinically relevant mouse cSCC model with two defined neoantigens that mediate tumor rejection. Structural changes in the exposure of features that promote T cell receptor recognition defined tumor-rejecting neoantigens. Incorporation of structural modeling to predict changes in T cell receptor accessibility is anticipated to improve the selection of neoantigens for inclusion in personalized cancer vaccines.

Abstract Background and Objectives Research has established that unpaid family members, friends, or others who care for persons with dementia (ie, caregivers) may encounter socioemotional and physical health concerns as a consequence of providing extensive assistance. Similarly, caregivers for people living with traumatic brain injury (TBI) often experience a range of stressors and negative mental health outcomes due to care demands. Individuals with TBI often develop Alzheimer’s disease and Alzheimer’s disease-related dementia (AD/ADRD). This history of TBI may introduce complications to AD/ADRD caregiving. A comprehensive intervention grounded in the understanding of the complex caregiving context of both diagnoses is warranted to address the unique needs and concerns of TBI-AD/ADRD caregivers. Research Design and Methods This study evaluated the feasibility of the TBI-AD/ADRD Caregiver Support Intervention (TACSI) psychoeducational program, designed to support the unique subset of caregivers facing the challenge of assisting relatives with AD/ADRD and a history of TBI. TACSI, a 6-session telehealth intervention, provides tailored psychosocial and psychoeducational coaching. In partnership with the 2 national healthcare centers, 15 caregivers enrolled in the 3-month feasibility study evaluating the design and subsequent refinement of TACSI. Mixed methods data were collected from 3-month follow-up surveys and qualitative data from postintervention interviews. Results The feasibility, utility, and acceptance of TACSI were established. Caregivers liked the telehealth delivery and the personalized nature of TACSI, yet some expressed it would have been more beneficial earlier in their caregiving journey. Discussion and Implications Caregivers valued the TACSI program. Their feedback has been applied to improve TACSI content and delivery for a larger pilot randomized controlled trial that is currently underway.

ABSTRACT Objective To estimate the incidence, prevalence, patient characteristics and healthcare utilization patterns of moderate to severe thyroid eye disease (TED) in the United States. Design Retrospective review of medical and prescription claims data from the Inovalon deidentified claims database. Patients Patients with moderate to severe TED were identified based on specific and sensitive definitions using International Classification of Diseases (ICD) codes selected by a group of TED specialists. Results The incident moderate to severe TED population included 3364 and 1730 patients using the sensitive and specific definitions, respectively. After adjusting for age and gender, corresponding incidence rates in the sensitive and specific populations were 8.97 (13.49 in women and 4.27 in men) and 4.37 (6.59 in women and 2.05 in men) per 100,000 person‐years, respectively. The prevalent population included 16,310 and 8018 patients using the sensitive and specific definitions, respectively, corresponding to adjusted prevalence rates of 44.13 (66.00 in women and 21.39 in men) and 20.55 (31.18 in women and 9.50 in men) per 100,000 persons. A preponderance of women was observed, and comorbidity rates were high, with > 40% of prevalent patients experiencing hypertension. Steroids were the most frequently prescribed medication. The impact of teprotumumab was not captured, since this study only included claims data through 2019. Conclusions The estimated incidence and prevalence rates of TED demonstrate the considerable impact of this disease in the United States, making the creation of a specific ICD code imperative for effective healthcare planning and management.

Abstract Colorectal cancer is the second leading cause of cancer-related mortality in adults in the United States. Despite compelling evidence of improved outcomes in colorectal cancer, screening rates are not optimal. This study aimed to characterize colorectal cancer screening trends over the last two decades and assess the impact of various screening modalities on overall colorectal cancer screening rates. Using National Health Interview Survey data from 2005 to 2021, we examined colorectal cancer screening [colonoscopy, multitarget stool DNA (mt-sDNA), fecal occult blood test (FOBT)/fecal immunochemical test, sigmoidoscopy, CT colonography] rates among adults ages 50–75 years (n = 85,571). A pseudo-time-series cross-sectional (pseudo-TSCS) analysis was conducted including a random effects generalized least squares regression model to estimate the relative impact of each modality on changes in colorectal cancer screening rates. Among 50 to 75 year olds, the estimated colorectal cancer screening rate increased from 47.7% in 2005 to 69.9% in 2021, with the largest increase between 2005 and 2010 (47.7%–60.7%). Rates subsequently plateaued until 2015 but increased from 63.5% in 2015 to 69.9% in 2018. This was primarily driven by the increased use of mt-sDNA (2.5% in 2018 to 6.6% in 2021). Pseudo-TSCS analysis results showed that mt-sDNA contributed substantially to the increase in overall screening rates (77.3%; P < 0.0001) between 2018 and 2021. While colorectal cancer screening rates increased from 2005 to 2021, they remain below the 80% goal. The introduction of mt-sDNA, a noninvasive screening test may have improved overall rates. Sustained efforts are required to further increase screening rates to improve patient outcomes and offering a range of screening options is likely to contribute to achieving this goal. Prevention Relevance: This retrospective study highlights the importance of convenient stool-based colorectal cancer screening options to achieve the national goal of 80% for overall colorectal cancer screening rates. Empowering screening-eligible individuals with a choice for their colorectal cancer screening tests is imperative.

67 Background: Colorectal cancer (CRC) is the second leading cause of cancer-related mortality among men and women combined in the United States (US). Although the national screening rate has increased over the years, it remains below the target of 80% recommended by the National Colorectal Cancer Roundtable for improved CRC outcomes. In most recent years, and particularly during COVID-19, screening-eligible individuals preferred at-home, non-invasive screening options over invasive tests such as colonoscopy due to convenience and accessibility. The objective of this study was to understand the CRC screening trends over the last two decades, and the impact of various screening modalities on the overall CRC screening rate. Methods: Using National Health Interview Survey (NHIS) data from 2005 onwards, we examined CRC screening (colonoscopy, mt-sDNA, FIT/FOBT, and sigmoidoscopy) rates among adults aged 50-75 years. A pseudo-time-series cross-sectional (pseudo TSCS) analysis was conducted including random effects Generalized Least Square (GLS) regression model to estimate the relative impact of each modality on the overall increase in CRC rates from 2018 to 2021. Results: Among 50-75 years old individuals, the estimated CRC screening use increased by 32% from 2005 to 2021 (47.7% to 69.9%). Between 2018 to 2021, the rates increased from 64% to 70%, driven largely by increased use of mt-sDNA, a 62.1% increase from 2018 to 2021 (2.5% to 6.6%). During this time period, colonoscopy utilization increased by 4.4% (61.2% to 64.0%), while FOBT/FIT utilization increased by 3.6% (5.3% to 5.5%). A pseudo-TSCS analysis showed that mt-sDNA contributed substantially to the overall CRC screening rate increase during years 2018-2021 (77.3%; p < 0.0001). Conclusions: While CRC screening rates are increasing, they remain below the national goal of 80%. Mt-sDNA as a home-based, non-invasive screening, recommended at a 3-year interval, has been leveraged to improve overall CRC screening rates, particularly to address the screening backlog created during the COVID-19 pandemic. A collaborative approach between healthcare providers and screening-eligible individuals is needed to empower patients with choice for their CRC screening modality to achieve the national goal.

e13631 Background: Colorectal cancer (CRC) screening disruptions have been observed with the COVID-19 pandemic, putting patients at risk for more advanced-stage disease at the time of diagnosis. We estimated the impact of increased use of stool-based tests for screening during the COVID-19 pandemic on near-term clinical outcomes in a simulated United States (US) population. Methods: A previously developed budget impact model was adapted to assess the impact of increasing use of multi-target stool DNA [mt-sDNA] or fecal immunochemical [FIT] tests to offset the COVID-19 related disruption in colonoscopy screening. Adults, ages 50 – 75 years, at average risk for CRC were included over a 3-year time horizon (2020 – 2023) to explore the impact of increased screening for CRC using mt-sDNA or FIT, from the perspective of a US payer. Compared to the base case (S0; 85% colonoscopy and 15% non-invasive tests), the estimated number of missed CRCs and advanced adenomas (AAs) were determined for four COVID-19-affected screening scenarios: S1, 9 months of CRC screening at 50% capacity, followed by 21 months at 75% capacity; S2, S1 followed by increasing stool-based testing by an average of 10% over 3-years; S3, 18 months of CRC screening at 50% capacity, followed by 12 months of 75% capacity; and S4, S3 followed by increasing stool-based testing by an average of 13% over 3-years. Results: Increasing the proportional use of mt-sDNA, the detection of AAs improved by 6.0% (Scenario 2 versus 1) to 8.4% (Scenario 4 versus 3) and the number of missed CRCs decreased by 15.1% to 17.3% respectively. Increasing FIT utilization improved the detection of AAs by 3.3% (Scenario 2 versus 1) to 4.6% (Scenario 4 versus 3) and the number of missed CRCs decreased by 12.9% (Scenario 2 versus 1) to 14.9% (Scenario 4 versus 3). Across all scenarios, the number of AAs detected was higher for mt-sDNA than for FIT, and the number of missed CRCs was lower for mt-sDNA than for FIT. Conclusions: Using home-based stool tests for average-risk CRC screening can mitigate the consequences of reduced colonoscopy screening resulting from the COVID-19 pandemic. Use of mt-sDNA led to fewer missed CRCs and more AAs detected, compared to FIT.

AbstractBackgroundGuidelines include several options for average‐risk colorectal cancer (CRC) screening that vary in aspects such as invasiveness, recommended frequency, and precision. Thus, patient and provider preferences can help identify an appropriate screening strategy. This study elicited CRC screening preferences of physicians and individuals at average risk for CRC (IAR).MethodsIAR aged 45–75 years and licensed physicians (primary care or gastroenterology) completed an online discrete choice experiment (DCE). Participants were recruited from representative access panels in the US. Within the DCE, participants traded off preferences between screening type, screening frequency, true‐positive, true‐negative, and adenoma true positive (physicians only). A mixed logit model was used to obtain predicted choice probabilities for colonoscopy, multi‐target stool DNA (mt‐sDNA), fecal immunochemical test (FIT), and methylated septin 9 (mSEPT9) blood test.ResultsPreferences of IAR and physicians were affected by screening precision and screening type. IAR also valued more regular screening. Physicians preferred colonoscopy (96.8%) over mt‐sDNA (2.8%; p < 0.001), FIT (0.3%; p < 0.001) and mSEPT9 blood test (0.1%; p < 0.01). IAR preferred mt‐sDNA (38.8%) over colonoscopy (32.5%; p < 0.001), FIT (19.2%; p < 0.001), and mSEPT9 blood test (9.4%; p < 0.001). IAR naïve to screening preferred non‐invasive screening (p < 0.001), while the opposite was found for those who previously underwent colonoscopy or sigmoidoscopy.ConclusionsWhile physicians overwhelmingly preferred colonoscopy, preferences of IAR were heterogenous, with mt‐sDNA being most frequently preferred on average. Offering choices in addition to colonoscopy could improve CRC screening uptake among IAR.This study used a discrete choice experiment in the US to elicit preferences of physicians and individuals at average risk for colorectal cancer screening modalities and their characteristics.