Importance Elevated low-density lipoprotein cholesterol (LDL-C) is a modifiable risk factor for cardiovascular disease, the leading cause of premature death worldwide. Assessing the LDL-C–related burden is critical for guiding prevention and treatment strategies. Objectives To estimate the global, regional, and national burden of ischemic heart disease and ischemic stroke attributable to elevated LDL-C (relative to 35-54 mg/dL) from 1990 to 2023 and to quantify the contributions of population growth, aging, risk-deleted burden, and exposure changes to burden trends. Design, Setting, and Population This comparative risk assessment, part of the Global Burden of Disease Study 2023, estimated population-level LDL-C exposure and associated health loss in 204 countries and territories. Mean LDL-C levels were estimated using spatiotemporal gaussian process regression based on 806 studies across 161 countries. Relative risks were derived from meta-analyses of 38 randomized clinical trials. Population-attributable fractions for deaths and disability-adjusted life-years (DALYs) were estimated by age and sex for adults aged 25 years or older from 1990 to 2023, with 95% uncertainty intervals. Exposure Population-level LDL-C concentrations. Main Outcomes and Measures Population-attributable fractions, counts, and rates (all ages and age standardized per 100 000) of LDL-C–attributable deaths and DALYs from ischemic heart disease and ischemic stroke, with uncertainty intervals. Results In 2023, elevated LDL-C accounted for 3.6 million deaths (95% uncertainty interval, 2.2-5.4 million; 6.0% of global mortality) and 90.7 million DALYs (95% uncertainty interval, 58.9-123.3 million; 3.2% of DALYs). Although global all-ages rates remained stable, age-standardized death and DALY rates decreased by 45.6% and 39.5%, respectively, since 1990. In 2023, age-standardized LDL-C–attributable DALY rates were highest in Eastern Europe and lowest in high-income Asia-Pacific. One-third of the global LDL-C burden occurred in India and China. Population growth and aging drove the increasing burden, with notable regional disparities in LDL-C exposure and risk-deleted DALY rates shifting toward middle-sociodemographic settings. Conclusions and Relevance Despite declining age-standardized rates, the absolute LDL-C burden has increased since 1990 due to demographic changes and has shifted toward middle-sociodemographic countries. Measurement and surveillance gaps persist. Strengthened prevention, diagnosis, and treatment access strategies are essential to mitigate the health burden of LDL-C.
Abstract B090: Radiation-induced oral mucositis to rapidly determine effective radiosensitizing dosing regimens for ATM and DNAPK inhibitors
Abstract Failure to repair radiation (RT)-induced DNA damage results in cell lethality, and combined treatment with DNA repair inhibitors can markedly enhance tumor control achieved with radiation. These inhibitors also can potentiate acute RT toxicities by suppressing DNA repair. Capitalizing on this normal tissue radiosensitizing effect, we determined effective radiosensitizing dosing regimens in mice for the ATM inhibitor WSD0628 and the DNAPK inhibitor WNC0901 in mice. Drugs were administered via oral gavage prior to each RT dose, and RT was delivered using an anterior/posterior 225 kVp beam. In an initial iteration of this model, various combinations of WSD0628 and RT were administered to cohorts of mice (n=5/group) and body weight was followed for 2 weeks. The resulting data were modeled to define the total dose of radiation estimated to cause 50% of mice to lose >20% body weight (D50). There was an inverse relationship between the WSD0628 and D50 doses: 0 mg/kg WSD0628/24.0 Gy (95% confidence interval (CI) 24.5–24.7); 0.25 mg/kg/19.2 Gy (95% CI 16.7–21.8); 1 mg/kg/13.7 Gy (95% CI 13.2–14.2); 2.5 mg/kg/11.0 Gy (95% CI 10.5–11.5); 5 mg/kg/11.3 Gy (95% CI 6.7–15.9) and 7.5 mg/kg/7.8 Gy (95% CI 7.8–7.9). Histological review of tongues from animals treated with 15 Gy RT (5Gy x 3) + 7.5 mg/kg WSD0628 demonstrated epithelial denudation and acute inflammation consistent with oral mucositis, while these features were not seen with the same dose as RT alone. Similar WSD0628 doses were evaluated in combination with 8 Gy supratentorial RT (via lateral beams) in orthotopic GBM43 PDX tumors. By treatment arm, the median time to a moribund state was: sham (29 days (d)), RT (39d), 1 mg/kg (42d), 2.5 mg/kg (49d), 5 mg/kg (65d), and 10 mg/kg (123d, overall p<0.0001). A second mucositis model was used for evaluation of WNC0901. Cohorts of 5 mice/group were treated with a set dose of RT (4Gy x 3) to the oral cavity alone and in combination with various doses of WNC0901, and the fraction of mice with >20% weight loss within 2 weeks was determined. The results of this study are as follows: placebo (0 of 5 mice with >20% weight loss); 15 mg/kg (3 of 5 mice); 25, 50, or 100 mg/kg (5 of 5 mice). Based on these data, we defined 25 mg/kg WNC0901 as the minimally effective dose and predicted that 50 mg/kg would provide robust radiosensitization. Consistent with this prediction, co-treatment of B16 melanoma flank tumor xenografts with RT (8Gy x 1) and WNC0901 (50 mg/kg) more than doubled the median tumor control duration (median 42 [range 24-45] days; time from implantation for tumor to exceed 1500 mm3) as compared to RT alone (24 [13-30] days) or sham treatment (17 [13-17] days; overall p<0.0001). This study describes how a radiation-induced oral mucositis model can be used to identify effective radiosensitizing regimens faster and with fewer resources than relying on tumor control studies alone. Citation Format: Danielle Burgenske, Darwin Garcia, Jiayan Le, Wenjuan Zhang, Sneha Rathi, Katrina K. Bakken, Lauren L. Ott, Zeng Hu, Brett L. Carlson, Ann Mladek, Jessica L. Abraham, Paul A. Decker, Matthew L . Kosel, Jeanette E. Eckel-Passow, William F. Elmquist, Wei Zhong, Jann N. Sarkaria. Radiation-induced oral mucositis to rapidly determine effective radiosensitizing dosing regimens for ATM and DNAPK inhibitors [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2025 Oct 22-26; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2025;24(10 Suppl):Abstract nr B090.
Bystander Effects, Pharmacokinetics, and Linker-Payload Stability of EGFR-Targeting Antibody-Drug Conjugates Losatuxizumab Vedotin and Depatux-M in Glioblastoma Models
Abstract Purpose: Antibody-drug conjugates (ADC) are targeted therapies with robust efficacy in solid cancers, and there is intense interest in using EGFR-specific ADCs to target EGFR-amplified glioblastoma (GBM). Given GBM’s molecular heterogeneity, the bystander activity of ADCs may be important for determining treatment efficacy. In this study, the activity and toxicity of two EGFR-targeted ADCs with similar auristatin toxins, Losatuxizumab vedotin (ABBV-221) and Depatuxizumab mafodotin (Depatux-M), were compared in GBM patient-derived xenografts (PDX) and normal murine brain following direct infusion by convection-enhanced delivery (CED). Experimental Design: EGFRviii-amplified and non-amplified GBM PDXs were used to determine in vitro cytotoxicity, in vivo efficacy, and bystander activities of ABBV-221 and Depatux-M. Nontumor-bearing mice were used to evaluate the pharmacokinetics (PK) and toxicity of ADCs using LC-MS/MS and immunohistochemistry. Results: CED improved intracranial efficacy of Depatux-M and ABBV-221 in three EGFRviii-amplified GBM PDX models (Median survival: 125 to >300 days vs. 20–49 days with isotype control AB095). Both ADCs had comparable in vitro and in vivo efficacy. However, neuronal toxicity and CD68+ microglia/macrophage infiltration were significantly higher in brains infused with ABBV-221 with the cell-permeable monomethyl auristatin E (MMAE), compared with Depatux-M with the cell-impermeant monomethyl auristatin F. CED infusion of ABBV-221 into the brain or incubation of ABBV-221 with normal brain homogenate resulted in a significant release of MMAE, consistent with linker instability in the brain microenvironment. Conclusions: EGFR-targeting ADCs are promising therapeutic options for GBM when delivered intratumorally by CED. However, the linker and payload for the ADC must be carefully considered to maximize the therapeutic window.
Abstract B028: Systemic and CNS distributional pharmacokinetics of WSD0628, a novel radiosensitizer: Implications for the treatment of brain tumors
Abstract Glioblastoma (GBM) is an aggressive and highly infiltrative brain tumor with poor prognosis. Radiation therapy induces DNA damage, and DNA damage response (DDR) pathways modulate resistance to radiation therapy. Inhibiting DDR pathways by targeting ATM, a key enzyme involved in the repair of DNA double strand breaks, leads to radiosensitization and enhances cytotoxicity. Clinical translation of radiosensitizers for GBM may be influenced by a lack of effective drug delivery across the blood brain barrier (BBB). The purpose of this study is to determine the key preclinical pharmacokinetic parameters and mechanisms that influence the CNS delivery of WSD0628, a novel ATM inhibitor. In vitro clonogenic survival assays using U251 GBM cells indicate that WSD0628 shows significant radiosensitization, with a >70% decrease in surviving colonies in the presence of 10nM or higher drug concentrations in combination with 2.5 to 10 Gy radiation as compared to radiation alone. We evaluated the systemic pharmacokinetics and CNS distribution of WSD0628 in FVB wild-type mice and FVB mice lacking Pgp and Bcrp (Mdr1a/b−/−Bcrp1−/−, triple knockout) after a 1, 5, 10 mg/kg intravenous (IV) or oral (PO) dose. Clearance decreased with increase in dose and a greater than dose proportional increase in exposure was observed. WSD0628 is rapidly absorbed and is bioavailable after oral administration. Tissue distribution coefficients were determined as the ratio of exposure in tissue to plasma (Kp = AUCtissue/AUCplasma). Kp,brain was 0.22 ± 0.05, and Kp, spinal cord was 0.30 ± 0.09 in the wild-type mice. For wild-type mice, Kp,uu,brain was 0.20 ± 0.05 and Kp,uu,spinal cord was 0.26 ± 0.08, determined by correcting for binding to CNS tissues and plasma. The brain distribution of WSD0628 was only modestly increased (1.4 times) in the triple knockout mice with Kp,brain of 0.32 ± 0.06 and Kp,spinal cord of 0.41 ± 0.08. Organ distribution of WSD0628 at steady-state was studied after intraperitoneal implantation of Alzet osmotic pumps primed to release WSD0628 at 7.5 ug/hr for 25 hours. Tissue distribution coefficients, determined by organ-to-plasma steady-state concentration ratios, were highest for liver and kidneys, followed by heart, lungs and CNS. Survival studies conducted in mice bearing orthotopic GBM patient derived xenografts show a significant improvement in survival in mice receiving a combination of WSD0628 and radiation as compared to radiation alone. In conclusion, WSD0628 is a robust radiosensitizer and has moderate brain penetration that is not limited by the efflux transporters Pgp and Bcrp. Based on preliminary efficacy studies in mice, WSD0628 shows potential for treatment of GBM tumors. Evaluations are underway to determine tumor free concentrations and quantification of corresponding biomarkers. Combining this knowledge of PK of WSD0628 with the dynamics of the targeted biological pathway will inform a PK-PD-efficacy model and predict effective dosage regimens for future preclinical and clinical trials. Citation Format: Sneha Rathi, Ann Mladek, Zhiyi Xue, Ju-Hee Oh, Wenjuan Zhang, Wenqiu Zhang, Jiayan Le, Jann S. Sarkaria, William F. Elmquist. Systemic and CNS distributional pharmacokinetics of WSD0628, a novel radiosensitizer: Implications for the treatment of brain tumors [abstract]. In: Proceedings of the AACR Special Conference on Brain Cancer; 2023 Oct 19-22; Minneapolis, Minnesota. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_1):Abstract nr B028.
Abstract B023: CNS and systemic pharmacokinetics of antibody-drug conjugate payloads through convection-enhanced delivery
Abstract Glioblastoma (GBM) is one of the most malignant central nervous system (CNS) tumors and accounts for more than 60% of primary brain tumors in adults [1]. While chemotherapy is a frequently employed treatment for GBM, its lack of specificity towards tumor cells leads to toxicity in healthy tissues. Antibody-drug conjugates (ADCs) are a prevalent targeted-drug delivery strategy that may enhance the therapeutic window. ADC development for GBM has progressed in recent years, yet recent clinical trials have thus far failed to demonstrate drug efficacy [2]. This is likely attributed to poor brain penetration and heterogeneous drug distribution within GBM [3]. Convection-enhanced delivery (CED) is an invasive delivery method that can achieve direct administration of therapeutics to brain tumors and potentially could be used to enhance the delivery and efficacy of ADCs. This study investigates the CNS and systemic pharmacokinetics and distribution of similar payload molecules following CED administration of two GBM-targeting ADCs, ABBV-221 and ABT-414. The ADC payloads are monomethyl auristatin E (MMAE) and monomethyl auristatin F (MMAF), respectively, and both are potent anti-tubulin toxins commonly used as warheads for ADCs. Both ADCs and free MMAE were administered as single doses to FVB mice via CED infusion or intraperitoneal (IP) injection. Plasma and brain samples were collected over 24 hours for ABBV-221 and 96 hours for ABT-414, and unconjugated payload molecules were quantified via LC-MS/MS analysis. The results showed that free (i.e., not bound to the targeting antibody) MMAE has a significantly higher exposure in brain compared to plasma when delivered via CED, and exposure in the right hemisphere was 10-fold higher than the left hemisphere, as the site of CED infusion was located in the right hemisphere for all trials. Similar results for MMAE payload were observed after the CED of ABBV-221. Systemic administration of ABBV-221 resulted in a nearly 100-fold decrease in unconjugated MMAE concentration in brain, indicating the poor brain penetration of the ADC. Similarly, following the CED of ABT-414, unconjugated payload concentration was the highest in right anterior brain among all brain regions, and plasma concentration was below the limit of quantification. Systemic injection of ABT-414 resulted in non-quantifiable payload concentrations in either brain or plasma samples. Taking these results as a whole, this study demonstrated significantly enhanced brain distribution of payload molecules from GBM-targeting ADCs following CED compared to systemic administration. The consistent payload delivery pattern observed in both ADCs further supports the potential of CED as an effective drug delivery method for the treatment of GBM. These findings highlight the promise of CED as a means to address the limitations of conventional chemotherapy and improve therapeutic outcomes in GBM treatment. 1. Sarkaria JN et al. Neuro Oncol. 2018; 20:184–91. 2. Lassman AB et al. Neuro Oncol. 2023; 25:339–50. 3. Marin B-M, et al. Neuro Oncol. 2021; 23:2042–53. Citation Format: Jessica I. Griffith, Jiayan Le, Kendra A. Porath, Sonia Jain, Katrina K. Bakken, Jann N. Sarkaria, William F. Elmquist. CNS and systemic pharmacokinetics of antibody-drug conjugate payloads through convection-enhanced delivery [abstract]. In: Proceedings of the AACR Special Conference on Brain Cancer; 2023 Oct 19-22; Minneapolis, Minnesota. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_1):Abstract nr B023.
Intubation Practices and Adverse Peri-intubation Events in Critically Ill Patients From 29 Countries