Citations

TPS2677 Background: Despite the success in hematologic malignancies, CAR T therapies face significant challenges in solid tumors due to the lack of tumor-specific targets that distinguish cancer from normal cells. EGFR plays a critical role in oncogenesis across several cancers and is often upregulated (TCGA 2022). While monoclonal antibodies targeting EGFR have demonstrated efficacy, these approaches are often limited by on-target, off-tumor toxicities, such as skin rash, which constrains dose escalation and efficacy (Macdonald, et al. J Am Acad Dermatol . 2015). A2B395 is an allogeneic, logic-gated, EGFR-targeted Tmod CAR T therapy designed to address these limitations and provide a convenient and consistent off-the-shelf option. This therapy incorporates 2 CARs: an activator targeting EGFR, and a blocker targeting HLA-A*02. The activator recognizes EGFR on both tumor and normal cells, while the blocker inhibits CAR T activity against normal cells with preserved HLA expression and decreases the risk for graft-versus-host disease (Hamburger, et al. Mol Immunol . 2020). To address potential host-vs-graft response, an shRNA expression module targeting B2M is included in the Tmod construct, which significantly reduces major histocompatibility complex class I levels and subsequent host immune response (DiAndreth, et al. Clin Immunol. 2022). Importantly, the Tmod system is modular and adaptable to multiple targets. Initial data on autologous Tmod CAR T therapy suggest reduced off-tumor toxicity and encouraging clinical efficacy (Grierson, et al. SITC 2024. Abstract 588). A2B395 represents a novel approach for EGFR-expressing solid tumors with HLA-A*02 LOH. Methods: DENALI-1 (NCT06682793) is a phase 1/2, open-label, nonrandomized study evaluating the safety and efficacy of A2B395 in adults. Patients are enrolled through BASECAMP-1 (NCT04981119), a master prescreening study that identifies patients with HLA LOH at any time in the course of their disease via next-generation sequencing (Tempus AI, Inc.). Key inclusion criteria include histologically confirmed recurrent unresectable, locally advanced, or metastatic cancers associated with EGFR expression, including colorectal, non-small cell lung, squamous cell head and neck, triple negative breast, and renal cell cancers. Patients must have received ≥1 line of prior therapy, such as a checkpoint inhibitor, molecular targeted therapy, or chemotherapy. The primary objective of phase 1 is to evaluate safety, tolerability, and the recommended phase 2 dose (RP2D) using a Bayesian optimal interval design for dose escalation. The dose-expansion phase will confirm RP2D and collect biomarker data. Phase 2 will assess overall response rate per RECIST v1.1. Clinical trial information: NCT06682793 .

Abstract Background: Chimeric antigen receptor T-cell (CAR T) therapies have demonstrated significant clinical efficacy in hematologic malignancies, but have proven challenging in solid tumors, in part owing to a lack of tumor-specific targets and unmanageable toxicity. Mesothelin (MSLN) expression normally is limited to the mesothelium of major body cavities but can be upregulated in diverse solid tumor types (cancer.gov/tcga), making it a potential target for cancer therapy. MSLN-targeted cell therapy approaches, including CAR T and T-cell receptor fusion therapies, have shown promising clinical activity; however, on-target, off-tumor toxicity including fatal events have occurred (Beatty, et al. Gastroenterology. 2018.; Haas, et al. Mol Ther. 2023.; Hong, et al. ESMO 2021. Abstract 9590.). A2B694 is an autologous logic-gated, MSLN-targeted Tmod CAR T therapy that addresses the challenges of on-target, off-tumor toxicity by combining 2 CARs: an activating and blocking receptor. The activator recognizes MSLN present on the surface of both tumor and normal cells; the blocker inhibits the CAR T activator when it binds human leukocyte antigen (HLA)-A*02, which is present in normal cells and often lost in tumor cells. Thus, in patients with tumor-associated HLA-A*02 loss of heterozygosity (LOH), the blocker prevents on-target, off-tumor toxicity on normal cells owing to retained HLA-A*02 expression (Hamburger, et al. Mol Immunol. 2020). Through this unique selective mechanism, A2B694 may provide a therapeutic window to treat patients with MSLN-expressing solid tumors exhibiting HLA-A*02 LOH. Methods: EVEREST-2 (NCT06051695) is a first-in-human, phase 1/2, open-label, nonrandomized study to evaluate the safety and efficacy of A2B694 in adults with recurrent unresectable, locally advanced, or metastatic cancers with MSLN expression, including non-small cell lung cancer, colorectal cancer, pancreatic cancer, ovarian cancer, mesothelioma, or other solid tumors with MSLN expression. Eligible patients must have progressed following standard of care therapy. Enrollment to EVEREST-2 occurs through the prescreening study BASECAMP-1 (NCT04981119), which identifies patients with tumor-associated HLA-A*02 LOH via next-generation sequencing (Tempus AI, Inc). Eligible patients enroll in the BASECAMP-1 study and undergo leukapheresis. A2B694 is manufactured from cryopreserved T cells when clinically appropriate for patients. The primary objective of phase 1 is to evaluate the safety and tolerability of A2B694 and identify the recommended phase 2 dose (RP2D). The dose-expansion phase will confirm RP2D and collect biomarker data to further characterize A2B694. Phase 2 will assess overall response rate per RECIST v1.1. The first patient was enrolled on EVEREST-2 in April 2024. Dose escalation is ongoing. Citation Format: Julian R. Molina, Antonious Hazim, Oliver Dorigo, Salman R. Punekar, Monica Avila, Diane M. Simeone, Kedar Kirtane, Gottfried E. Konecny, Jeffrey Ward, Matthew Block, Jennifer Specht, Leslie Boyd, Yanyan Lou, Jong Chul Park, Jacqueline D. Xuan, Ramez N. Eskander, Gayanie Ong, Marco Davila, Wendy Langeberg, Marcela Maus, Armen Mardiros, Frederick L. Locke, Andrea Wise, David G. Maloney, John Welch, J. Randolph Hecht. EVEREST-2: A seamless phase 1/2 study of A2B694, a logic-gated Tmod CAR T-cell therapy, in patients with mesothelin-expressing solid tumors with human leukocyte antigen-A*02 loss of heterozygosity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_2):Abstract nr CT186.

Abstract Reprogramming of aged donor tissue cells into induced pluripotent stem cells (A-iPSC) preserved the epigenetic memory of aged-donor tissue, defined as genomic instability and poor tissue differentiation in our previous study. The unbalanced expression of RNA exosome subunits affects the RNA degradation complex function and is associated with geriatric diseases including premature aging and cancer progression. We hypothesized that the age-dependent progressive subtle dysregulation of EXOSC2 (exosome component 2) causes the aging traits (abnormal cell cycle and poor tissue differentiation). We used embryonic stem cells as a tool to study EXOSC2 function as the aging trait epigenetic memory determined in A-iPSC because these aging traits could not be studied in senesced aged cells or immortalized cancer cells. We found that the regulatory subunit of PP2A phosphatase, PPP2R5E, is a key target of EXOSC2 and this regulation is preserved in stem cells and cancer.

AbstractObjectiveThe objective of this study is to determine if a history of traumatic brain injury (TBI) degrades postoperative the audiological performance of patients with cochlear implantation (CI).Study DesignRetrospective review.SettingDepartment of Defense‐wide database.MethodsInternational Classification of Diseases, Ninth Revision (ICD‐9) and ICD‐10 codes were used to identify patients that were diagnosed with TBI prior to CI between 2005 and 2023. They were matched 2:1 with controls without TBI based on age and sex. Preoperative and postoperative pure tone average (PTA) thresholds and AzBio scores were compared.ResultsNineteen TBI patients representing 20 implanted ears were identified and matched with 39 patients without TBI representing 40 implanted ears. Thirteen ears carried a diagnosis of mild TBI, and seven were diagnosed with moderate to severe TBI. The average follow‐up period was 44 months. The TBI group attained mean postoperative PTA and AzBio scores of 37 dB (SD 24) and 67% (SD 28). The non‐TBI group attained scores of 31 dB (SD 12) and 69% (SD 26). P‐values for the PTA and AzBio intergroup comparisons were .93 and .88, respectively. All TBI ears attained at least sound awareness after implantation, with 79% achieving open‐set speech perception compared to 82% of non‐TBI ears.ConclusionCI after TBI of any severity provides hearing rehabilitation comparable to patients without a prior diagnosis of TBI.

831 Background: Long non-coding RNA (lncRNA)-based genomic profiling has suggested utility to identify a distinct tumor subgroup corresponding to a favorable prognosis in patients with bladder cancer. Here, we further evaluate a genomic classifier in a cohort of patients undergoing radical cystectomy (RC). Methods: Transcriptome-wide expression profiling using Decipher Bladder was performed on TURBT samples from a cohort of patients with high grade, clinically organ confined (cTa-T2N0M0) UC who subsequently underwent RC without any neoadjuvant therapy (n=226). LncRNA-based luminal favorable status was determined using a previously developed genomic classifier. The primary endpoint was overall survival (OS) following surgery. Secondary endpoints included cancer-specific mortality and upstaging at RC. Results: In the study, 134 patients were clinical NMIBC (cTa/Tis/T1) and 92 patients were cT2. We identified 60 patients with luminal favorable subtype, all of which showed robust gene expression patterns associated with less aggressive bladder cancer biology. On MVA, patients with the luminal favorable subtype (vs. without) were significantly associated with lower odds of upstaging to pT3+ disease (OR [95% CI] 0.32 [0.12-0.82], p = 0.02), any upstaging (OR [95% CI] 0.41 [0.20-0.83], p = 0.01), and any upstaging and/or pN+ (OR [95% CI] 0.50 [0.25-1.00], p = 0.05). Luminal favorable bladder cancer was significantly associated with better OS (HR 0.33 [95% CI 0.15-0.74], p=0.007). Conclusions: This study validates the performance of the genomic classifier for identifying urothelial carcinomas with a luminal favorable subtype, harboring less aggressive tumor biology.

Abstract Background The association of body composition with checkpoint inhibitor outcomes in melanoma is a matter of ongoing debate. In this study, we aim to investigate body mass index (BMI) alongside computed tomography (CT)-derived body composition metrics in the largest cohort to date. Methods Patients treated with first-line anti-PD1 ± anti-CTLA4 for advanced melanoma were retrospectively identified from 11 melanoma centers in The Netherlands. From baseline CT scans, 5 body composition metrics were extracted: subcutaneous adipose tissue index, visceral adipose tissue index, skeletal muscle index, density, and gauge. These metrics were correlated in univariable and multivariable Cox proportional hazards analysis with progression-free survival, overall survival, and melanoma-specific survival (PFS, OS, and MSS). Results A total of 1471 eligible patients were included. Median PFS and OS were 9.1 and 38.1 months, respectively. Worse PFS was observed in underweight patients (multivariable hazard ratio [HR] = 1.86, 95% CI = 1.14 to 3.06). Furthermore, prolonged OS was observed in patients with higher skeletal muscle density (multivariable HR = 0.88, 95% CI = 0.81 to 0.97) and gauge (multivariable HR = 0.61, 95% CI = 0.82 to 0.998), whereas higher visceral adipose tissue index was associated with worse OS (multivariable HR = 1.12, 95% CI = 1.04 to 1.22). No association with survival outcomes was found for overweight, obesity, or subcutaneous adipose tissue. Conclusion Our findings suggest that underweight BMI is associated with worse PFS, whereas higher skeletal muscle density and lower visceral adipose tissue index were associated with improved OS. These associations were independent of known prognostic factors, including sex, age, performance status, and extent of disease. No significant association between higher BMI and survival outcomes was observed.

Background. Early allograft dysfunction (EAD) affects outcomes in liver transplantation (LT). Existing risk models developed for deceased-donor LT depend on posttransplant factors and fall short in living-donor LT (LDLT), where pretransplant evaluations are crucial for preventing EAD and justifying the donor’s risks. Methods. This retrospective study analyzed data from 2944 adult patients who underwent LDLT at 17 centers between 2016 and 2020. We developed a logistic regression model to predict EAD based on this development cohort. We used data from 1020 patients at the King Faisal Transplant Center for external validation. Results. In the development cohort, 321 patients (10.9%) experienced EAD. These patients had poorer health status, more liver decompensation, and higher requirements of hospitalization than those without EAD. Multivariable logistic regression identified independent pretransplant predictors of EAD: laboratory Model for End-Stage Liver Disease score (odds ratio [OR], 1.08; 95% confidence interval [CI], 1.06-1.09), the necessity for hospitalization at the time of transplant (OR, 2.58; 95% CI, 2.00-3.30), and graft weight in kilogram (OR, 0.27; 95% CI, 0.17-0.45). Using these predictors, we developed the model for EAD after LDLT, which demonstrated strong discriminative ability in the development cohort with an area under the curve (AUC) of 0.71 (95% CI, 0.68-0.74). The model maintained high discrimination during internal validation (AUC, 0.70; 95% CI, 0.67-0.73) and showed a modest reduction in discriminative power in external validation (AUC, 0.65; 95% CI, 0.61-0.68). Conclusions. EAD post-LDLT is influenced by the recipient’s pretransplant health condition and the graft weight. Integrating the model for EAD after LDLT into the pretransplant process of pairing donors and recipients can enhance the safety and efficacy of LDLT.

766 Background: BASECAMP-1 (NCT04981119) is a pre-screening study to identify patients with tumor-associated human leukocyte antigen (HLA)-A*02 loss of heterozygosity (LOH) for interventional studies, such as EVEREST-2 (NCT06051695), a phase 1/2 study of logic-gated chimeric antigen receptor T-cell (CAR T) therapy for MSLN-expressing cancers. MSLN is a cell surface protein expressed in several cancer types, including mesothelioma (MESO), colorectal (CRC), non-small cell lung (NSCLC), ovarian (OVCA), and pancreatic (PANC) cancer, which can be associated with poor prognosis (1). Longitudinal clinical, genomic, and biomarker data were collected from patients enrolled in BASECAMP-1, providing a large dataset for translational discovery and propensity scoring. The aim of this analysis was to determine whether MSLN expression measured by RNAseq and IHC are correlated among patients with solid tumors. Methods: In BASECAMP-1, tumor tissue from patients with germline heterozygous HLA-A*02 is tested for HLA-A*02 LOH using an investigational next generation sequencing device codeveloped with Tempus Labs (Lozac'hmeur, et al. NPJ Precis Oncol. 2024) that detects somatic alterations, including HLA LOH, and generates RNAseq data (eg, MSLN expression). Gene-level transcripts per million read (TPM) values were determined and the log2 TPM +1 was displayed in a scatter plot (the mean and standard deviation [SD] are provided in the Table). Patients with HLA-A*02 LOH also submit tissue for IHC testing for exploratory biomarkers (eg, MSLN expression using anti-MSLN clone 5B2). Statistical significance was determined with ANOVA or t-tests. Results: As of June 1, 2024, 314 patients had been screened for BASECAMP-1 and had RNAseq results; 34 patients also had MSLN IHC results. MSLN expression by RNAseq was consistently higher in patients with PANC or OVCA vs CRC or NSCLC ( P <0.001). MSLN expression by RNAseq and IHC were correlated overall ( P <0.001), particularly among patients with PANC and OVCA. Among the 8 patients with OVCA or PANC who were IHC+ for MSLN, only 1 had an RNAseq value below 6 log2 TPM+1; this patient had mesonephric-like ovarian adenocarcinoma, which may account for the low value. The one MESO sample with both RNAseq and IHC available was IHC+ and had a high RNAseq value. Conclusions: This analysis demonstrated high correlation between RNAseq and IHC MSLN expression in tumor tissue. 1. Faust, et al. Cancers. 2022. Clinical trial information: NCT04981119 . MSLN expression by RNASeq by tumor type and IHC status. Tumor Overall (N=314) IHC data available (n=34) MSLN Positive MSLN Negative n Mean TPM a (SD) n Mean TPM a (SD) n Mean TPM a (SD) All 314 5.1 (2.3) 20 6.0 (2.1) 14 2.3 (1.7) adNSCLC 33 3.8 (2.4) 2 4.7 (1.7) 7 1.5 (1.3) sqNSCLC 4 3.1 (1.8) 0 0 MESO 4 4.5 (4.2) 1 5.7 0 CRC 148 4.4 (2.0) 8 5.1 (2.1) 7 3.1 (1.6) PANC 100 6.1 (1.8) 3 7.8 (0.6) 0 OVCA 25 7.2 (2.1) 5 6.6 (2.8) 0 a MSLN log2 transcripts per million+1. ad, adenocarcinoma; sq, squamous.

Introduction: The Mindfulness-Based Stress Reduction program for breast cancer survivors (MBSR [BCs]) is a stress-reducing program designed to increase cognitive functioning through four meditational practices. This randomized clinical trial aimed to determine if improvements in cognitive functioning and perceived cognitive abilities achieved from the MBSR(BC) were mediated through increased mindfulness, decreased rumination, and decreased perceived stress. Methods: Breast cancer survivors (BCSs) who met inclusion criteria of stage I, II, or III BC and received either chemotherapy (CT) or both CT and radiation were randomized to either the 6-week MBSR(BC), or Breast Cancer Education Support (BCES) program, or to a usual care (UC) regimen. Analysis of covariance was first implemented to identify potential mediators, followed by a formal mediational analysis to evaluate the effects of MBSR(BC) on 6-, 12-, and 26-week outcomes. Results: After consent, 212 BCS were randomized to MBSR(BC) ( n = 91), BCES ( n = 90), or UC ( n = 31). The mean age was 56.5 and the majority of the BCS, 73.1%, were White and non-Hispanic. Results showed increases in “observing” as part of mindfulness as a potential mediator of MBSR(BC) effects on impairments on quality of life and logical memory at 6 months relative to UC. No mediation effects were identified for outcomes measured at 6 or 12 weeks and also when MBSR(BC) was compared with the BCES program. Discussion: These results partially supported our hypothesis that improvement in cognitive functioning would occur through increased mindfulness. Although few mediating relationships were identified, results showed a relationship between mindfulness and cognitive functioning. Both mediating relationships occurred through increases in “observing,” a subconcept of “mindfulness,” when compared to the MBSR(BC) with UC at 6 months. This study shows that mediators may help “optimize” clinical therapeutic treatment effects, thus contributing to the advancement of science. Trial Registration: ClinicalTrials.gov, www.ClinicalTrials.gov . Registration Number: NCT02786797.