Citations

BET bromodomain inhibitors are efficacious as anti-inflammatory compounds, but clinical translation is hampered by dose-limiting toxicities from non-selective inhibition. We herein report compounds 16 and 26, based on previously reported 4-methyl-1,2,3-triazole-based inhibitor, DW34. 16 has a BRD4 BD1 Ki of 10 nM, and up to 13–38-fold selectivity for BRD4 BD1 over other BD2 domains, and an improved hERG affinity of 4.24 µM over DW34. 26, A biscyclopropyl analog of 16 showed further enhancement of BD1 selectivity over BD2 (26–203-fold), but exhibited more potent hERG inhibition. Compound 16 had improved liver and plasma clearance over DW34, with good biodistribution to the liver, and had an intracellular target-engagement affinity Ki of 92 nM, with reduction of Ccl2, Cxcl1, AST, and ALT in in vitro and in vivo mouse models of liver inflammation. 16 represents a useful lead for treating inflammatory liver diseases, with improved specificity, drug-like properties, and reduced hERG affinity.

Abstract Rural and low-socioeconomic status women face social determinants of health barriers leading to disproportionately low rates of breast cancer screening and markedly reduced participation in clinical trials. To address this gap, we developed the WeCARE (Women’s Engagement for Cancer Awareness, Resources, and Education) intervention using a community-engaged approach. This paper describes how Community Advisory Board feedback informed the development of Mayo Clinic Health System’s WeCARE intervention components. Their input was systematically analyzed using the Consolidated Framework for Implementation Research (CFIR 2.0) to identify determinants of acceptability, appropriateness, and feasibility and to guide actionable refinements to intervention content and delivery.

TPS655 Background: Early (14-28 day) on-treatment suppression of tumor proliferation during neoadjuvant endocrine therapy (NET) is strongly associated with favorable long-term outcomes in estrogen receptor–positive (ER+) HER2– breast cancer. In premenopausal women, tamoxifen with or without ovarian function suppression (OFS) results in suboptimal Ki-67 suppression compared with aromatase inhibitor + OFS. (Z)-endoxifen (ENDX), the active metabolite of tamoxifen, dually inhibits ER signaling and PKCβ1-mediated AKT activation, supporting its evaluation as an alternative NET strategy in this population. Methods: EVANGELINE (NCT05607004) is an ongoing, multicenter, open-label Phase 2 study evaluating daily 40 mg ENDX plus goserelin administered every 28 days as neoadjuvant therapy in premenopausal women with ER+/HER2–, cT2–3, cN0–1 breast cancer. The primary objective is to determine the proportion of patients with baseline Ki-67 >10% who achieve Ki-67 ≤10% after 4 weeks of therapy. A Simon two-stage design is used to test whether the Week 4 Ki-67 ≤10% rate is at least 65%, with 20 patients enrolled into the first stage and, if promising, another 25 patients enrolled into the second stage (cohort A). A parallel cohort of 20 patients with baseline Ki-67 ≤10% (cohort B) is enrolled to assess objective response rate (ORR) at 24 weeks per RECIST v1.1. Secondary objectives include examining safety and tolerability, residual cancer burden, and PEPI score. Correlative analyses include examining effect of treatment on select tumor and plasma biomarkers. Clinical trial information: NCT05607004 .

Abstract Introduction: We aimed to characterize the preclinical pharmacokinetics (PK) of a series of 20 anticancer agents in highly immunodeficient female NOD scid gamma (NSG) mice to provide clearance and exposure data for agents under investigation by the NCI PDX Development and Trial Centers Research Network (PDXNet). Methods: The series of 20 anticancer agents (inhibitors of CDK4/6, PI3K-β/PI3K-δ, ATR, MEK1/2, PI3K, microtubule, EZH2, BCL-2, PARP, histone deacetylase, γ-secretase, FGFR, SHP2, and ERK1/2, as well as a SMAC mimetic) were administered to female NSG mice via IV, PO, or IP routes to characterize plasma exposures under conditions used for PDX efficacy testing. Serial plasma samples were collected 15, 30, 60, 120, 240, 360, 480, and 1440 minutes after dosing. Drug concentrations were quantified using validated LC-MS/MS assays. PK parameters were calculated using non-compartmental analysis. Results: The PK for each agent was determined, and the clearance and half-life values are listed in the table below. The PK metrics for Navitoclax could not be calculated. Due to higher metabolic rates, mice show faster PK processes. They generally had shorter half-lives and higher weight-normalized clearance than humans. Copanlisib, Navitoclax, and Trametinib were exceptions. Conclusion: These PK data are critical for understanding the antitumor activities of agents studied by the PDXNet and will aid investigators in developing new approach methodologies for preclinical safety studies in preparation for human clinical trials. Citation Format: Mohd Beshr Chama, Emily J. Koubek, Sarah A. Buhrow, Renee A. Schoon, Joel M. Reid. Pharmacokinetics of a series of anticancer agents in immunodeficient female NOD scid gamma mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 3156.

Abstract Introduction. This study aimed to characterize the population pharmacokinetics (PopPK) of nab-paclitaxel following the administration of the nano-immunoconjugate nab-paclitaxel-bevacizumab to patients with unresectable stage IV melanoma or gynecological cancers (NCT02020707). The core objective was to characterize the population mean drug concentration-time profile, understand the variability in drug concentrations and identify factors that explain differences in paclitaxel plasma clearance. Also, we sought to explore the impact of the nano-immunoconjugate formulation on paclitaxel clearance. Methods. Using Pumas AI - an advanced pharmacokinetic software program, integrating Machine Learning methods - a PopPK analysis was conducted using concentration-time data collected from 29 subjects, (681 concentration measurements). Patients received 75 - 175 mg/m2 (total dose, 160 - 360 mg). Data were fitted to a 2-compartment model based biphasic decline observed in plasma concentration following intravenous administration. A critical requirement for the model was the inclusion of saturable elimination to accurately describe the drug’s disposition. A comprehensive modeling workflow was implemented, starting with base models (mixed vs. non-linear clearance), followed by the sequential addition of covariates (Age, Sex, BSA, Tumor, Cycle). The Parsimony Principle was applied to select the most appropriate model. Results. Population estimates for paclitaxel clearance and volume of distribution were 41.7 L/hr and 312 L, respectively. The analysis found paclitaxel clearance higher when compared with published data for nab-paclitaxel alone (21.1 or 25 L/h/m2; Sparreboom et al, CCR 11:4136, 2005 and Ando et al, CCP 69:457, 2012). A covariate model incorporating BSA and Gender is the best. For every 2 m2 increase in BSA, linear clearance (CL) increases by 6.9%. Females have 16.6% lower CL than males, which successfully characterized systematic differences in PK between subgroups of subjects. Conclusion. The administration of nab-paclitaxel via the nano-immunoconjugate formulation led to increased clearance for paclitaxel consistent with known clearance mechanisms for therapeutic antibodies. The differences in drug clearance among patients were primarily attributable to covariates BSA and gender. These findings are crucial for identifying safe and effective dosing regimens and informing future clinical simulations. Citation Format: Mohd Beshr Chama, Matthew Stephen Block, Vera J. Suman, Joel M. Reid. Population pharmacokinetics of nab-paclitaxel following administration of a nano-immunoconjugate with bevacizumab [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 301.

Abstract Background The ability of large language models (LLMs) to work collaboratively and screen studies in a systematic review (SR) is under-explored. Hence, we aimed to evaluate the effectiveness of LLMs in automating the process of screening in systematic reviews. Methods This is an observational study which included labeled data (title and abstracts) for five SRs. Originally, two reviewers screened the citations independently for eligibility. A third reviewer cross-checked each citation for quality assurance. GPT-4, Claude-3-Sonnet, and Gemini-Pro-1.0 were used using zero-shot chain-of-thought prompting. Collaborative approaches included (i): conflict resolution using benefit of the doubt, (ii) majority voting using an independent third LLM and (iii) conflict resolution using an informed third LLM. Performance was assessed using accuracy, precision for exclusion, and recall for inclusion. Work saved over samples (WSS) was computed to estimate the reduction in manual human effort. Results A total of 11300 articles were included in this study. The individual models, GPT-4, Claude-3-Sonnet, and Gemini-Pro-1.0 exhibited a high precision for exclusion, achieving 99.7%, 99.7%, and 99.2% and high recall for inclusion achieving 95.5%, 96.6% and 85.7%, respectively. However, the collaborative approach utilizing the two best-performing models (GPT-4 and Claude-3S) achieved an average precision of 99.9% and a recall of 98.5% (across all collaborative approaches). Furthermore, the proposed collaborative approach resulted in an average WSS of 63.5%, compared to the average WSS of 45.2% for individual models. Conversational LLM interactions showed a consistent pattern of results. Limitations This study was limited due to reliance on proprietary models, and evaluation on oncology datasets. Conclusion Evidence shows that collaborative LLMs enable efficient, high-performing screening in systematic reviews, supporting continuous evidence updates. Primary funding source NIH (U24CA265879-01-1) and Carolyn-Ann-Kennedy-Bacon Fund.

Abstract WSD0922-Fu is an oral, CNS-penetrant, small molecule EGFR inhibitor which potently inhibits EGFR aberrations specific to non-small cell lung cancer (NSCLC) and glioblastoma (GBM). MC1914 (NCT04197934) is a first-in-human phase 1 trial in patients with EGFR aberrant recurrent GBM and NSCLC. After determining the maximum tolerated dose, adults with recurrent GBM were treated in two expansion cohorts: (a) non-surgical cohort (6/12 patients thus far): EGFRvIII mutation, first recurrence; food-effect study included (b) surgical cohort (6/6 patients), any EGFR mutation, any recurrence; window-of-opportunity study (WOO) included. Among these 12 patients, median age = 60 years; 50% female; 58% ECOG 0). All patients received prior radiation and temozolomide. After the WOO or food-effect study, patients were dosed at 120 mg BID (5 days on, 2 days off), and escalated to 160 mg BID (5 days on, 2 days off) based on tolerability. Common adverse events (>40%) are comparable to other EGFR inhibitors (acneiform rash, diarrhea, fatigue, xerosis, pruritis). Treatment-related grade 3+ adverse events were limited to lymphopenia (n = 1). WSD0922-Fu exposure in the fed state exceeded the fasted state (median plasma Cmax and AUC0-24h are 1.6x and 1.3x, respectively) with a delayed Tmax (6.0 vs 1.8 hours). For the WOO, time between last dose administered to tumor collection ranged between 4 - 13.5 hours. Median tumor WSD0922-Fu concentration was 0.76 µg/g; estimated median unbound tumor concentration was 24.9 ng/g and within expectations for pharmacodynamic effect. Median brain/plasma ratio = 0.59; median unbound brain/unbound plasma = 0.88. Enrollment to the non-surgical cohort is ongoing, so formal efficacy data remain immature. However, examples of clinical efficacy will be shown along with data on recurrence patterns. Phase 2 clinical trial development is in progress.

Abstract Purpose: Mouse models demonstrate a role for RANK and its ligand, RANKL, in osteosarcoma. The primary objective of this single-arm, open-label phase 2 trial was to determine whether denosumab, a RANKL mAb, improved disease control in recurrent osteosarcoma relative to benchmarks derived from historic Children’s Oncology Group clinical trial data. Patients and Methods: Skeletally mature patients ages 11 to 49 years old with measurable disease were eligible for cohort 1, and those with complete surgical resection of all sites of disease were eligible for cohort 2. Patients received denosumab 120 mg subcutaneously every 4 weeks with calcium and vitamin D supplementation. The primary endpoints were RECIST response and remaining event-free for 4 months for cohort 1 and remaining event-free for 12 months for cohort 2. Toxicity, pharmacokinetics, and pharmacodynamic effects were additional endpoints. Results: Fifteen patients in cohort 1 and 38 in cohort 2 were eligible and evaluable for the primary endpoint. One of 15 cohort 1 patients remained event-free at 4 months. There were no objective responses. Ten of 38 cohort 2 patients were event-free at 12 months. The predefined efficacy criteria were not met in either cohort. The most common ≥ grade 3 adverse events were hypocalcemia and hypophosphatemia (8% and 11%, respectively). At steady state, mean serum denosumab trough concentrations were 23.7 to 31 μg/mL in cycles 2 to 7. Serum c-telopeptide and urine n-telopeptide decreased on treatment. Conclusions: Denosumab was well-tolerated with anticipated side effects and pharmacokinetic and pharmacodynamic parameters but had insufficient activity for further development in osteosarcoma.

PURPOSE Human epidermal growth factor receptor 2 (HER2), a transmembrane receptor with kinase activity involved in cell signaling through the RAS pathway, is expressed in osteosarcoma (OST). Trastuzumab deruxtecan (T-DXd) is an antibody-drug conjugate with a HER2-targeting monoclonal antibody, trastuzumab, linked to a topoisomerase I inhibitor. We report results of a phase II study of T-DXd in adolescents and young adults with HER2-positive relapsed, unresectable OST (ClinicalTrials.gov identifier: NCT04616560 ). METHODS Patients age 12-39 years with relapsed, unresectable OST were eligible for centrally evaluated HER2 expression screening by immunohistochemistry. Patients with >10% of OST cells with cytoplasmic or membranous HER2 expression of any intensity were eligible to receive T-DXd at 5.4 mg/kg intravenously once every 3 weeks for up to 2 years. The study used a 9 + 15 Simon's optimal two-stage design with a primary end point of event-free survival at 24 weeks. RESULTS Fifty patients were screened for HER2, and 41 met the inclusion criteria of 10% of OST cells having membranous or cytoplasmic HER2 expression. Nine eligible patients, two younger than 18 years, were enrolled and received T-DXd. With a single patient having more than 24 weeks of stable disease (SD) of the nine planned in the first stage, this study did not meet criteria to progress to stage II. The estimated SD rate at 24 weeks is 11.1%. The median (range) number of cycles of therapy was 2 (2-12). Grade 3 and 4 possibly related adverse events occurred in three of nine patients and included nausea, vomiting, tumor hemorrhage, cytopenias (n = 3), wound infection, and hypertension. CONCLUSION T-DXd did not demonstrate sufficient activity to expand enrollment to the planned second stage in patients with OST. No new safety signals were observed.

10051 Background: CBL0137 is a novel agent that targets the FAcilitates Chromatin Transcription complex (FACT), a histone chaperone that regulates chromatin remodeling during transcription, replication, and DNA repair. CBL0137 has been shown to have anti-tumor activity in multiple preclinical models of pediatric cancer. We report the phase 1 trial of CBL0137 in children with relapsed or refractory solid tumors including central nervous system (CNS) tumors or lymphoma (NCT04870944). Methods: Patients (age 12 months to 21 years) with relapsed/refractory solid tumors, central nervous system tumors or lymphoma were eligible. In the dose escalation phase, a rolling-six design was used to evaluate CBL0137 administered intravenously (IV) once per week on Days 1 and 8 of a 21-day cycle. The starting dose was 400 mg/m 2 , with escalation to the adult phase 2 dose (RP2D) of 540 mg/m 2 . The maximum tolerated dose (MTD) was determined based on cycle 1 dose limiting toxicity (DLT) using Common Toxicity Criteria for Adverse Events (v5). Pharmacokinetics (PK) and cytokine analyses were performed during cycle 1. Seven additional patients ( < 18 years old) were accrued to a PK expansion cohort at the RP2D. Results: Sixteen patients were enrolled; 14 were evaluable for DLT assessment (12 at 400mg/m 2 [6 in dose escalation and 6 in PK expansion] and 2 at 540mg/m 2 ). The median (range) age was 10 (4-20) years. Diagnoses included high grade glioma (n = 6), osteosarcoma (n = 5), ependymoma (n = 2), neuroblastoma, hepatoblastoma and Burkitt’s lymphoma (1 each). One of 12 evaluable patients treated at 400 mg/m 2 experienced a DLT: Grade 3 photosensitivity. At 540 mg/m 2 , the two evaluable patients both had fever and dose limiting Grade 3 hypotension. Non-dose limiting Grade 3-4 toxicities included anemia, lymphopenia, neutropenia, thrombocytopenia, hypokalemia, anorexia, photosensitivity and fever. For both dose levels, a total of 12 patients were reported to have at least one episode of Grades 1-3 fever and/or Grade 1 cytokine release syndrome (CRS). PK parameters (mean±SD) for CBL0137 (400 mg/m 2 ) were T max = 0.7 ± 0.5 h, C max = 1310 ± 417 ng/mL, and AUC 0-24h = 15300 ± 6790 h·ng/mL. Given the unexpected toxicities of fever, hypotension, and CRS, cytokine samples were collected in patients enrolled in the PK expansion cohort; all had Grade 1 CRS and significantly elevated levels of both IL-10 (adj p = 0.001) and IL-1RA (adj p < 0.001) at 24 hours vs pre-infusion. Conclusions: The RP2D and MTD of CBL0137 in children and adolescents with solid or CNS tumors is 400mg/m 2 IV weekly on Days 1 and 8 of 21-day cycles. CBL0137 leads to immune activation, with cytokine elevation and the possibility of CRS, an unexpected toxicity not previously reported in adults. A Phase 2 cohort in patients with Diffuse Midline Glioma is ongoing and includes further assessment of immune activation. Clinical trial information: NCT04870944 .