Intrapatient Variability Research Articles

Abstract PO4-06-04: Understanding metastasis mixed-treatment responses through genomic analyses

Abstract Background Early-stage and metastatic breast cancer (MBC) exhibit genomic heterogeneity, with inter-patient variability between primary tumors, intra-patient variability of primary tumors versus metastasis, and even between different metastatic sites within the same patient. Response to therapy in MBC can also be heterogeneous, termed "mixed response", with different degrees of responsiveness to the same drug(s) across metastatic sites within the same patient. Whether this treatment response variability is influenced by factors such as intrinsic characteristics of metastatic lesions and/or the microenvironment is unknown. Through genomic analysis, we aim to identify genomic features that may explain mixed clinical responses across metastatic sites, which will also provide valuable insights into treatment sensitivity and resistance. Methods Eligible patients with MBC were identified from the UNC Rapid Autopsy Program (RAP) with primary tumors and multiple metastases (≥ 2 different sites) with RNA sequencing data. An independent radiologist retrospectively reviewed imaging studies to identify patients with mixed radiographic responses to a defined line of therapy. The response to treatment was categorized for each metastasis, defined as a complete or partial response, as stabilization ≥ 6 months. Tumor measurements were performed for each patient at different time points. We performed supervised learning with linear regression incorporating "RNA sequencing-based gene expression signatures" as a fixed effect and "patient" as a random effect. We performed two different analyses: (1) Using all tumors and (2) using Basal-like tumors only. We finally selected significant signatures with a p-value >0.05. Results Ten patients with mixed response were identified, and 33 metastases were used for the analysis; 3 had de novo stage IV disease, 5 had triple-negative (TNBC), 4 HER2+, and 4 hormone receptor+ (HR+/HER2-) disease. Of 33 metastases, 6 were brain, 8 liver, 7 lung, and 12 “other”. Regarding intrinsic subtype, 15 metastatic tumors were Basal-like, 3 HER2-Enriched (HER2E), 6 Luminal A, and 9 Luminal B. In this dataset, 6 metastatic lesions showed response and 27 non-response. When analyzing all 33 metastases, KRAS high expression, KRAS amplicon, 16q23 amplicon, and apocrine features correlated with response independently of metastatic site. Higher T reg and CDKN2A gene expression levels were associated with non-response in metastasis. Within Basal-like subtype metastases only (N=15), CD8 T cells, PI3K pathway, KRAS gene and amplicon, 16q23 amplicon, and Basal-like-associated 5q11 loss correlated with response. However, T reg cells, higher levels of CDKN2A gene, and stem-cell-like features were associated with treatment non-response. Conclusions By examining matched metastases with discordant responsiveness to treatment within individual patients, this genomic analysis provides valuable insight into treatment sensitivity and resistance. Higher T reg cells and CDKN2A gene expression values correlate with non-response, while the KRAS gene, KRAS amplicon, and the 16q23 amplicon were associated with response. These results suggest that the molecular tumor and microenvironment features of metastases may contribute to sensitivity and resistance to therapy in MBC. Further validation and exploration are needed in larger multi-metastatic cohorts to fully understand the clinical implications of these findings. Citation Format: Susana Garcia-Recio, Paola Zagami, Amy Wheless, Kerry Thomas, Lisa Carey, Charles M Perou. Understanding metastasis mixed-treatment responses through genomic analyses [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-06-04.

Abstract PO3-16-03: Investigating HER2DX genomic assay concordance within HER2-positive breast cancer

Abstract Background: The HER2DX genomic assay, encompassing a 27-gene panel, provides prognostic (risk-score) and predictive (pathological complete response [pCR]-score) information while quantifying ERBB2 mRNA expression (ERBB2-score). This study aims to explore the variability of HER2DX scores within tumor samples and between paired diagnostic biopsies and surgical specimens. Methods: The standardized HER2DX assay was conducted on pretreatment FFPE biopsies from two distinct geographical areas within tumors (i.e., two different core biopsies) of patients enrolled in the 14-409 phase II study. This study assessed the impact of HER2 heterogeneity on treatment response in stage II-III HER2+ breast cancer patients treated with neoadjuvant T-DM1 and pertuzumab. Additionally, HER2DX was evaluated on paired biopsy-surgery FFPE samples from 6 patients who underwent primary surgery without pre-operative treatment. Variability and concordance of the three HER2DX groups scores were calculated, and Pearson's correlation coefficient determined the correlation between scores at different sites/time points. Paired t-tests were performed between tumor samples for the HER2DX scores. Results: The HER2DX assay was evaluated in two different diagnostic pre-treatment core biopsies from 106 patients (n=212 HER2DX assays). Intra-tumor concordance rates of the three HER2DX groups (risk-score, pCR-score, and ERBB2-score) were 94.3%, 87.7%, and 91.5%, respectively. No significant differential expression of HER2DX scores was observed across paired core biopsies (p-values=0.327 [risk-score], 0.415 [pCR-score], and 0.451 [ERBB2-score]). The average score differences (core 1 - core 2 [scale from 0 to 100]) were 0.57 (risk-score), 0.63 (pCR score), and -0.63 (ERBB2-score). Correlation coefficients across paired core biopsies were 0.96 (risk-score), 0.91 (pCR-score), and 0.90 (ERBB2-score). Additionally, intra-patient variability of the HER2DX scores was evaluated. Average variability in risk-score was 3.38% (95% CI: 2.76-4.01), in pCR-score was 3.53% (95% CI: 2.84-4.23) and in ERBB2 was 3.87% (95% CI: 2.97-4.77). In 6 patients with cT1-2 cN0 disease, HER2DX was evaluated in a diagnostic core biopsy and a surgical specimen, with an average time interval of 8.5 weeks (range 4 to 12 weeks) between time points. The intra-patient concordance rates of the three HER2DX groups were 83.3%, 83.3%, and 100% for risk-score, pCR-score, and ERBB2-score, respectively. No significant differential expression of HER2DX scores was found across paired biopsy-surgery samples (p-values=0.814 [risk-score], 0.128 [pCR-score], and 0.607 [ERBB2-score]). The average score differences (core biopsy - surgical specimen [scale from 0 to 100]) were -0.67 (risk-score), -11.5 (pCR score), and 2 (ERBB2-score). Correlation coefficients across paired HER2DX assays were 0.97 (risk-score), 0.87 (pCR-score), and 0.94 (ERBB2-score). Conclusion: The HER2DX genomic assay demonstrates low variability within HER2+ breast cancer, supporting its reliability as a consistent tool for assessing prognosis, the probability of pCR and ERBB2 quantitative expression. Citation Format: Fara Brasó-Maristany, Laia Paré, Guillermo Villacampa, Mercedes Marín-Aguilera, Paul Spellman, Adrienne Waks, Ian Krop, Esther Sanfeliu, Zhequi Li, Patricia Galván, Eva Hernández-Illán, Pedro Jares, Joan Antón Puig-Butillé, Ana Vivancos, Patricia Villagrasa, Joel S. Parker, Charles M. Perou, Sara Tolaney, Otto Metzger, Kornelia Polyak, Aleix Prat. Investigating HER2DX genomic assay concordance within HER2-positive breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-16-03.

Tacrolimus Intrapatient Variability on Graft Outcomes inAdherent Renal Transplantation Patients: A Cross-SectionalStudy.

Tacrolimus is the mainstem of immunosuppressive therapy in kidney transplant patients. It has high intrapatient variability (Tac-IPV), which has been reported to affect graft function by predisposing patients to rejection or nephrotoxicity. We conducted this study with the aim of assessing the influence of Tac-IPV on 2-year graft function, biopsy-proven rejection, and infections in compliant renal recipients. In this single-center retrospective analytic cross-sectional study, 250 patients who underwent transplantation from March 21, 2018, to March 20, 2020 and had at least three outpatient tacrolimus trough levels on the same daily dose 6 to 12 months after transplantation were recruited. Tac-IPV was defined as a coefficient variation of > 15%. Graft function, biopsy-proven rejection, cytomegalovirus (CMV) and BK virus viremia, and calcineurin inhibitor (CNI) toxicity were evaluated. Of 202 transplant recipients, 128 were included with a mean age of 45.48 ± 13.14 years. The median Tac-IPV was 13.28% with 43.75% of patients with Tac-IPV > 15%. There were no significant differences in graft function, rejection, CNI toxicity, and CMV viremia among the groups during the 24-month study (P > .05). However, BK viremia was significantly higher among patients with Tac-IPV > 15% (13 vs. 2.9%, P = .042). The risk of antibody mediated rejection alone (22.7 vs. 2.9%) or any kind of rejection (22.7 vs. 11.8%) was significantly higher in patients with higher Tac-IPV, and in those who had mean trough levels below 7 ng/mL (P = .015, .032; respectively). Tac-IPV is low in adherent patients (with the median of 13.28%) and maintaining tacrolimus trough level above 7 ng/mL can overcome the adverse graft outcome of Tac-IPV in compliant kidney transplant recipients. DOI: 10.52547/ijkd.7815.

Evaluation of safety margins for cone beam CT-based adaptive prostate radiotherapy

Adaptive radiotherapy is characterized by the use of a daily imaging system, such as CBCT (Cone-Beam Computed Tomography) images to re-optimize the treatment based on the daily anatomy and position of the patient. By systematically re-delineating the Clinical Target Volume (CTV) at each fraction, target delineation uncertainty features a random component instead of a pure systematic. The goal of this work is to identify the random and systematic contributions of the delineation error and compute a new relevant Planning Target Volume (PTV) safety margin.169 radiotherapy sessions from 10 prostate cancer patients treated on the Varian ETHOS treatment system have been analyzed. Intra-patient and inter-patient delineation variabilities were computed in six directions, by considering the prostate as a rigid, non-rotating volume. By doing so, we were able to directly compare the delineations done by the physicians on daily CBCT images with the initial delineation done on the CT-sim and MRI, and sort them by direction using the polar coordinates of the points. The computed variabilities were then used to compute a PTV margin based on Van Herk margin recipe.The total margin computed with random and systematic delineation uncertainties was of 2.7, 2.4, 5.6, 4.8, 4.9 and 3.6 mm in the left, right, anterior, posterior, cranial and caudal directions, respectively.According to our results, the gain offered by the separation of the delineation uncertainty into systematic and random contributions due to the adaptive delineation process justifies a reduction of the PTV margin down to 3 to 5 mm in every direction.

A Review on Transdermal Drug Delivery System

Transdermal patches are designed to deliver drugs across the skin membrane without causing pain. This method of drug delivery, known as transdermal delivery, was first used in 1981 when Ciba-Geigy smarketed Transdermal V (now marketed as Transderm Scop) to prevent nausea and vomiting associated with motion sickness. Transdermal patches are pharmaceutical preparations of varying sizes, containing one or more active ingredients, which are applied to unbroken skin to deliver the active ingredient after passing through the skin barriers, thus avoiding first-pass metabolism. Today, about 74% of drugs are taken orally and often prove ineffective. To improve drug efficacy, transdermal drug delivery systems have emerged. The main objective of these systems is to deliver drugs into systemic circulation through the skin at a predetermined rate with minimal inter- and intra-patient variations.

Quantitative noninvasive measurement of cerebrospinal fluid flow in shunted hydrocephalus.

Standard MRI protocols lack a quantitative sequence that can be used to evaluate shunt-treated patients with a history of hydrocephalus. The objective of this study was to investigate the use of phase-contrast MRI (PC-MRI), a quantitative MR sequence, to measure CSF flow through the shunt and demonstrate PC-MRI as a useful adjunct in the clinical monitoring of shunt-treated patients. The rapid (96 seconds) PC-MRI sequence was calibrated using a flow phantom with known flow rates ranging from 0 to 24 mL/hr. Following phantom calibration, 21 patients were scanned with the PC-MRI sequence. Multiple, successive proximal and distal measurements were gathered in 5 patients to test for measurement error in different portions of the shunt system and to determine intrapatient CSF flow variability. The study also includes the first in vivo validations of PC-MRI for CSF shunt flow by comparing phase-contrast-measured flow rate with CSF accumulation in a collection burette obtained in patients with externalized distal shunts. The PC-MRI sequence successfully measured CSF flow rates ranging from 6 to 54 mL/hr in 21 consecutive pediatric patients. Comparison of PC-MRI flow measurement and CSF volume collected in a bedside burette showed good agreement in a patient with an externalized distal shunt. Notably, the distal portion of the shunt demonstrated lower measurement error when compared with PC-MRI measurements acquired in the proximal catheter. The PC-MRI sequence provided accurate and reliable clinical measurements of CSF flow in shunt-treated patients. This work provides the necessary framework to include PC-MRI as an immediate addition to the clinical setting in the noninvasive evaluation of shunt function and in future clinical investigations of CSF physiology.

In-Depth Analysis of Diet Diary and Urine pH Measurements Improved Food Diet Reporting in Postmenopausal Women with RUTI.

We proceeded with an in-depth review of diet diaries for nutrient analysis from a cohort of women suffering from uncomplicated recurrent urinary tract infection (RUTI) to validate the accuracy of our current food diet record (FDR) form and evaluate possible domains of improvement. As part of an IRB-approved study, this previously published cohort of NHANES-comparable women was analyzed for consistency of the nutrient intake over 3 days, the influence of the time between meals and urine pH, the effect of nutrient intake over interval time between meals, and seasonal and before/during the COVID-19 pandemic changes. Intrarater reliability for nutrient analysis and intrapatient variability for urine pH were computed to test for consistency. Intrarater reliability for diet analysis was 91% accurate for foods and beverage matching and nutrient analysis. Mean standard deviation of urine pH readings within study participants was 0.4 (95% CI: 0.4, 0.5). An association was noted between total calories and fat consumed at breakfast and an increase in time to lunch. Calories consumed were unaffected across seasons or during the COVID-19 pandemic. Water intake during summer was significantly lower than that during fall and winter (both, p < 0.001). The patients who reported drinking water had a significantly lower average urine pH than women who did not report drinking water (5.8 vs. 6.2; p = 0.026). In this cohort of postmenopausal women with RUTIs, in-depth analysis of our current FDR findings led to several actionable items, which will improve our current food diet self-reporting process by our patients.

Perspectives on Transdermal Drug Delivery System: A Review

Drug delivery system (DDS) is a collective term used for techniques that carry drugs into or throughout the body for administration and distribution of drug substances to the target cells, specific tissues or desired organs, to exert optimal effects. Among various routes of DDS, the transdermal drug delivery system (TDDS) forms an attractive approach compared to other routes of administration in terms of easy application, non-invasive, avoiding first pass metabolism, for systemic / local effect, directly reaches blood stream, target drug delivery, controlled release of the drug, easy termination of drug action by removing the patch, suitable for geriatric, paediatric subjects, unconscious patients, enhanced subject compliance and decreased side effects and inter and intra-patient variability as well. In this review, we focused on physiology of skin, routes of percutaneous absorption and types of TDDS, design, development and formulation approaches, basic elements, pharmacokinetics, factors affecting drug penetration, characterization and its evaluation. Significant discussion of their specific advantages, benefits especially in pain management, clinical considerations, general guidelines for using TDDS, market demand etc. This article also provides valuable literature for suitability of most of the Non-steroidal anti-inflammatory drugs (NSAIDs) for transdermal administration mainly due to their pharmacological aspects. In recent years, the scope of TDDS has increased in national as well as foreign market. Hence there are increased research activities from many pharma companies and research institutes for potential drug candidates for TDDS. The promising response of transdermal patches has spurred further research and development in this area. The global transdermal patch pipeline is overflowing, pointing to a bright future for these patches in the coming years. Therefore, TDDS may be the best alternative to oral formulations for effective treatment of inflammatory conditions.

Influence of Tacrolimus Intrapatient Variability on Allograft Rejection Frequency and Survival Following Liver Transplantation.

Tacrolimus is the primary calcineurin inhibitor used in immunosuppressive regimens to prevent allograft rejection (AR) after organ transplantation. Recent studies have linked intrapatient variability (IPV) of tacrolimus with AR occurrence and reduced survival, especially in kidney transplant recipients. However, limited data are available on the impact of tacrolimus IPV on adverse outcomes after liver transplantation (LT). The aim of this study was to assess the association between tacrolimus IPV using various methodologies with acute AR and long-term patient survival after LT. All patients who underwent LT from January 2010 to July 2021 were retrospectively evaluated. Tacrolimus IPV was calculated for each patient using the mean and SD, mean absolute deviation (MAD), coefficient of variation (CV), and time in therapeutic range (TTR). These measures were then compared with AR within the first 24 months after LT and to long-term survival. Out of 234 patients, 32 (13.7%) developed AR and 183 (78.2%) survived, with a mean follow-up of 101 ± 43 months. Tacrolimus IPV, assessed by mean, SD, MAD, and CV, was 8.3 ± 2.1, 2.7 ± 1.3, 32.0% ± 11.7%, and 39.4% ± 15.4%, respectively. There was no statistically significant correlation between Tacrolimus IPV and AR or survival post-LT. In a large cohort of patients from diverse racial backgrounds, tacrolimus IPV was not associated with clinically relevant outcomes such as AR and survival after LT.

A New Dosing Frontier: Retrospective Assessment of Effluent Flow Rates and Residual Renal Function Among Critically Ill Patients Receiving Continuous Renal Replacement Therapy.

In 2020, cefiderocol became the first Food and Drug Administration-approved medication with continuous renal replacement therapy (CRRT) dosing recommendations based on effluent flow rates (QE). We aimed to evaluate the magnitude and frequency of factors that may influence these recommendations, that is, QE intrapatient variability and residual renal function. Retrospective observational cohort study. ICUs within Hartford Hospital (890-bed, acute-care hospital) in Connecticut from 2017 to 2023. Adult ICU patients receiving CRRT for greater than 72 hours. CRRT settings including QE and urine output (UOP) were extracted from the time of CRRT initiation (0 hr) and trends were assessed. To assess the impact on antibiotic dosing, cefiderocol doses were assigned to 0 hour, 24 hours, 48 hours, and 72 hours QE values per product label, and the proportion of antibiotic dose changes required as a result of changes in inpatient's QE was evaluated. Among the 380 ICU patients receiving CRRT for greater than 72 hours, the median (interquartile range) 0 hour QE was 2.96 (2.35-3.29) L/hr. Approximately 9 QE values were documented per patient per 24-hour window. QE changes of greater than 0.75 L/hr were observed in 21.6% of patients over the first 24 hours and in 7.9% (24-48 hr) and 5.8% (48-72 hr) of patients. Approximately 40% of patients had UOP greater than 500 mL at 24 hours post-CRRT initiation. Due to QE changes within 24 hours of CRRT initiation, a potential cefiderocol dose adjustment would have been warranted in 38% of patients (increase of 21.3%; decrease of 16.6%). QE changes were less common after 24 hours, warranting cefiderocol dose adjustments in less than 15% of patients. Results highlight the temporal and variable dynamics of QE and prevalence of residual renal function. Data also demonstrate a risk of antibiotic under-dosing in the first 24 hours of CRRT initiation due to increases in QE. For antibiotics with QE-based dosing recommendations, empiric dose escalation may be warranted in the first 24 hours of CRRT initiation.

Abstract 6744: Activating anti-MDS immunity with polarized dendritic cell vaccines

Abstract Less than 50% of patients with higher-risk myelodysplastic syndromes (MDS) show clinical response to standard-of-care hypomethylating (HMA) therapy. Significant enthusiasm existed for immunotherapy/HMA combinations for these patients, but studies have failed to deliver on the initial promise. We have demonstrated that patients with MDS have a deficiency in antigen-presenting cells, called CD141Hi dendritic cells (DC). DC-deficient MDS patients have reduced response to HMAs, worse overall survival, and show less response to cancer vaccination. We hypothesized that restoration of this population using a novel DC vaccination approach - alpha-type-1 polarized dendritic cells (αDC1) - might compensate for this deficiency and restore immunity. To generate αDC1s, we collected monocytes from MDS patients and healthy donors (HD) and cultured them for 6 days in vitro in the presence of recombinant human GM-CSF and IL-4 followed by an additional 18-24 hours in the presence of αDC1 maturation factors (poly-I:C/IFNα/IFNγ/TNFα/IL-1β). Overall, we attempted to generate αDC1s from 15 MDS samples; 13/15 exhibited intermediate to very high-risk disease and 10/15 are currently receiving HMA therapy. We successfully cultured cells from 8/15 samples (53%). Of the 8 MDS samples, 5 were collected from patients receiving HMA therapy (62.5%). We were unable to successfully culture αDC1s from the other 5 patients receiving HMA therapy, and thus the effect of HMA therapy on aDC1 generation remains unclear. To test the function of MDS αDC1s, we focused on two signals necessary to activate immune responses: 1) the expression of co-stimulatory molecules and 2) the production of IL-12p70. Flow cytometric analysis on αDC1s and immature DCs from MDS samples revealed intra-patient variation in the fold-change surface expression of CD40/80/83/86 and HLA-DR proteins. Additionally, there was a trend towards decreased up-regulation of CD80 and CD86 in MDS specimens compared to HD. To assess production of IL-12p70, we stimulated immature DCs and αDC1s with CD40L and performed ELISA analysis on the media supernatant. We found that 3 out of 4 samples could produce IL-12p70 (range 27 - 5,480 pg/ml). To date, our results suggest that generation of MDS patient-derived αDC1 cells is feasible and additional work is being performed to fully characterize their ability to activate anti-MDS immune responses. Since αDC1s have an established safety profile in patients with solid tumors, we anticipate that we will be able to rapidly translate our results to the clinic. Citation Format: Daniel Alvarado, Jennifer Peresie, Adam Brinkman, Cheryl Allen, Weijian Jiang, Pawel Kalinski, Tiffany Tanaka, Elizabeth Griffiths, Michael Nemeth. Activating anti-MDS immunity with polarized dendritic cell vaccines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6744.

High intra-patient variability of tacrolimus within post-operative 1month predicted worse 1-year outcomes in pediatric liver transplant recipients.

The pharmacokinetics of tacrolimus (TAC) show high intra-patient variability (IPV), which is associated with poor long-term outcomes following adult liver transplantation(LT). However, this relationship remains to be confirmed in pediatric liver transplant (PLT) recipients. The present study aimed to investigate the association between TAC IPV and grafts or patient outcomes after pediatric liver transplantion. This retrospective study included 848 PLT recipients (including infants) between January, 2016, and June, 2021. The IPV of TAC concentrations was estimated by calculating the coefficient of variation (CV) of trough concentrations in whole blood within 1month after transplantation. Patients were categorized into two groups, low IPV (CV < 45%) and high IPV (CV ≥ 45%), based on the third quartile of the CV distribution. A total of 848 patients were included in our study. The low CV group included 614 patients, with a mean TAC trough concentration of 8.59 ± 1.65ng/ml and a median CV of 32.37%. In contrast, the high CV group included 214 patients, the mean TAC trough concentration and median CV were 8.81 ± 2.00ng/ml and 54.88%, respectively. The median hospital duration was significantly higher in the high CV group (22days vs. 20days, P = 0.01). Univariate analysis was performed to evaluate the significant differences in 1-year recipient survival (P = 0.041) and 1-year graft survival (P = 0.005) between the high- and low-CV groups. Moreover, high CV (HR 2.316, 95%CI 1.026-5.231, P = 0.043) and persistent EBV viremia (HR 13.165, 95%CI 3.090-56.081, P < 0.001) were identified as independent risk factors for 1- year mortality after PLT. PLT recipients with high TAC trough concentration of CV in the first month were associated with poor 1-year outcomes. This CV calculation provides a valuable strategy to monitor TAC exposure.

Feasibility of proton dosimetry overriding planning CT with daily CBCT elaborated through generative artificial intelligence tools

Radiotherapy commonly utilizes cone beam computed tomography (CBCT) for patient positioning and treatment monitoring. CBCT is deemed to be secure for patients, making it suitable for the delivery of fractional doses. However, limitations such as a narrow field of view, beam hardening, scattered radiation artifacts, and variability in pixel intensity hinder the direct use of raw CBCT for dose recalculation during treatment. To address this issue, reliable correction techniques are necessary to remove artifacts and remap pixel intensity into Hounsfield Units (HU) values. This study proposes a deep-learning framework for calibrating CBCT images acquired with narrow field of view (FOV) systems and demonstrates its potential use in proton treatment planning updates. Cycle-consistent generative adversarial networks (cGAN) processes raw CBCT to reduce scatter and remap HU. Monte Carlo simulation is used to generate CBCT scans, enabling the possibility to focus solely on the algorithm’s ability to reduce artifacts and cupping effects without considering intra-patient longitudinal variability and producing a fair comparison between planning CT (pCT) and calibrated CBCT dosimetry. To showcase the viability of the approach using real-world data, experiments were also conducted using real CBCT. Tests were performed on a publicly available dataset of 40 patients who received ablative radiation therapy for pancreatic cancer. The simulated CBCT calibration led to a difference in proton dosimetry of less than 2%, compared to the planning CT. The potential toxicity effect on the organs at risk decreased from about 50% (uncalibrated) up the 2% (calibrated). The gamma pass rate at 3%/2 mm produced an improvement of about 37% in replicating the prescribed dose before and after calibration (53.78% vs 90.26%). Real data also confirmed this with slightly inferior performances for the same criteria (65.36% vs 87.20%). These results may confirm that generative artificial intelligence brings the use of narrow FOV CBCT scans incrementally closer to clinical translation in proton therapy planning updates.

Abstract A105: Untangling the effect of ascites in shaping high grade serous ovarian cancer progression

Abstract High Grade Serous Ovarian Cancer (HGSOC) is the eighth cause of cancer-related mortality worldwide. Progress in eradicating this disease has been hampered by several factors, including the uncertainty about its tissues of origin, late diagnosis coupled to early dissemination through accumulation of ascitic fluid and extensive inter-patient variability. While being histopathologically homogeneous, HGSOC is characterized by several layers of heterogeneity that require the development of ad hoc research strategies and to focus on specific scales in order to deconvolve HGSOC pathogenetic mechanisms. In this context, our lab has previously shown that HGSOC can be derived both from the distal tract of the fallopian tube (fallopian tube epithelium, FTE) and the ovarian surface epithelium (OSE), with a prognostic impact for the tissue of origin and origin-specific molecular phenotypes, including an immune-suppressive response in the more aggressive OSE-derived subtype (Lo Riso, Villa et al. 2020), pointing at the role of tumor microenvironment in shaping therapeutical response. Moreover, we have also shown the role of ascitic fluid in sustaining the generation of single cell-derived metastatic ovarian cancer spheroids (sMOCS), that enrich for cancer stem-like cells, and allowing to identify a consistent intra-patient variability in response to carboplatin treatment (Velletri, Villa, Cilli, Barzaghi et al. 2022). To understand the specific impact of the tumor microenvironment in shaping HGSOC complexity, here we show an experimental framework aimed at the identification of the downstream effect of ascites in shaping cellular and molecular features of HGSOC. Here we leverage a newly generated single cell transcriptomic atlas, encompassing 1.5 million cells from 79 patients derived from primary tumors, ascites and metastatic samples, to identify specific expression networks activated during the metastatization process. In parallel, we derive from bulk transcriptomic data the set of genes that are induced upon ascitic fluid supplementation in 2D and 3D in vitro models, that are coupled to model-specific phenotypes, including cell proliferation, stemness and invasiveness. These genes are then integrated in the single-cell derived metastasis-specific expression networks to identify the upstream regulators imputable to ascitic fluid exposure. The linked regulators and downstream effectors are then used to identify in the atlas cell populations whose expression landscape is directly affected by ascitic fluid. The identification of such cell populations will allow to highlight cell-to-cell interactions existing between i) different tumor subpopulations; ii) tumor and tumor-associated compartments, in both primary and metastatic samples, that can be ascribed to the presence of ascitic fluid. Moreover, the molecular characterization of these interacting populations will allow to identify novel targets, paving the way to the identification of novel therapeutical avenues for HGSOC patients. Citation Format: Pietro Lo Riso, Carlo Emanuele Villa, Bianca Barzaghi, Marta R. Sallese, Giulia Picco, Alessia Gatto, Ugo Cavallaro, Giuseppe Testa. Untangling the effect of ascites in shaping high grade serous ovarian cancer progression [abstract]. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr A105.

First exploration of the on-treatment changes in tumor and organ uptake of a radiolabeled anti PD-L1 antibody during chemoradiotherapy in patients with non-small cell lung cancer using whole body PET

BackgroundIn patients with locally advanced unresectable non-small cell lung cancer (NSCLC), durvalumab, an anti-programmed cell death ligand-1 (PD-L1) antibody, has shown improved overall survival when used as consolidation therapy following...

Abstract TMP63: Blood Pressure (BP) Protocol Violations in IV Tenecteplase Treated Ischemic Stroke Patients is Associated With Early Neurologic Deterioration and Symptomatic Intracranial Hemorrhage

Background: The American Heart Association guidelines recommend BP goal of &lt;180/105 mmHg for the first 24 hours in acute ischemic stroke (AIS) patients treated with IV Alteplase and now adopted for IV Tenecteplase (TNK). Studies suggest increased hemorrhage risk in patients with BP ≥170 mmHg and greater BP variability. Methods: We performed a retrospective study with data from the Get with The Guidelines database and electronic medical record of all adult AIS patients treated with TNK at a Comprehensive Stroke Center from 6/2021 to 6/2023. All BP readings from ED arrival to 24 hours post TNK were queried. We analyzed the temporal trends of BP characteristics and their association with early neurological deterioration (END) and symptomatic intracranial hemorrhage (sICH). The BP characteristics included mean and standard deviation of systolic (SBP) and diastolic (DBP) measurements, intra-patient BP variability and frequency of excessive BP (SBP &gt; 180 mmHg and DBP &gt; 105 mmHg) at each time point. Results: There were 132 TNK treated patients: mean age 68 ± 15 years, 54% male, 73% Caucasian, median admission NIHSS 9, IQR 4-15, 42 (32%) underwent mechanical thrombectomy, 72 (54.5%) treated with IV antihypertensive(s). Of these, 6 (4.5%) developed END and another 6 (4.5%) sICH. Of the 5901 BP measurements, 217 (3.7%) and 99 (1.7%) exceeded systolic of &gt;180 mmHg and diastolic of &gt;105 mmHg respectively. All END and sICH patients had excessive BP within 4 hours post TNK (Figure 1) and during this time there was a strong association of END with excessive SBP (14% vs 4.8%; p=0.05) and DBP (14% vs 1.2%; p &lt; 0.001). sICH had a similar but weaker association: excessive SBP (7.7% vs 4.9%; p=0.3) and excessive DBP (3.8% vs 1.4%; p=0.2). Conclusion: Our findings suggest that excessive BPs within 4 hours of TNK may be associated with patients developing END and sICH. Further exploration of moderate BP parameters deserve further study post thrombolysis, like the BEST II study in post thrombectomy patients.

Deep Learning for Delineation of the Spinal Canal in Whole-Body Diffusion-Weighted Imaging: Normalising Inter- and Intra-Patient Intensity Signal in Multi-Centre Datasets.

Whole-Body Diffusion-Weighted Imaging (WBDWI) is an established technique for staging and evaluating treatment response in patients with multiple myeloma (MM) and advanced prostate cancer (APC). However, WBDWI scans show inter- and intra-patient intensity signal variability. This variability poses challenges in accurately quantifying bone disease, tracking changes over follow-up scans, and developing automated tools for bone lesion delineation. Here, we propose a novel automated pipeline for inter-station, inter-scan image signal standardisation on WBDWI that utilizes robust segmentation of the spinal canal through deep learning. We trained and validated a supervised 2D U-Net model to automatically delineate the spinal canal (both the spinal cord and surrounding cerebrospinal fluid, CSF) in an initial cohort of 40 patients who underwent WBDWI for treatment response evaluation (80 scans in total). Expert-validated contours were used as the target standard. The algorithm was further semi-quantitatively validated on four additional datasets (three internal, one external, 207 scans total) by comparing the distributions of average apparent diffusion coefficient (ADC) and volume of the spinal cord derived from a two-component Gaussian mixture model of segmented regions. Our pipeline subsequently standardises WBDWI signal intensity through two stages: (i) normalisation of signal between imaging stations within each patient through histogram equalisation of slices acquired on either side of the station gap, and (ii) inter-scan normalisation through histogram equalisation of the signal derived within segmented spinal canal regions. This approach was semi-quantitatively validated in all scans available to the study (N = 287). The test dice score, precision, and recall of the spinal canal segmentation model were all above 0.87 when compared to manual delineation. The average ADC for the spinal cord (1.7 × 10-3 mm2/s) showed no significant difference from the manual contours. Furthermore, no significant differences were found between the average ADC values of the spinal cord across the additional four datasets. The signal-normalised, high-b-value images were visualised using a fixed contrast window level and demonstrated qualitatively better signal homogeneity across scans than scans that were not signal-normalised. Our proposed intensity signal WBDWI normalisation pipeline successfully harmonises intensity values across multi-centre cohorts. The computational time required is less than 10 s, preserving contrast-to-noise and signal-to-noise ratios in axial diffusion-weighted images. Importantly, no changes to the clinical MRI protocol are expected, and there is no need for additional reference MRI data or follow-up scans.

P966 The intra-patient variability of adalimumab clearance during an intensive sampling study of Crohn’s disease patients receiving maintenance therapy

Abstract Background Lower adalimumab (ADA) clearance (CL) is associated with improved outcomes in Crohn’s disease (CD) and may be a superior pharmacokinetic (PK) measure than ADA concentrations. We compared intra-patient variability in ADA CL and concentrations within a 14-day treatment cycle and across two consecutive cycles under maintenance treatment. Methods In a previous PK study of CD patients receiving maintenance ADA 40mg fortnightly, samples were collected intensively at 3 visits (day 4-6, 7-9, and 13-14 post dose) across 2 consecutive cycles. Available sera from this cohort were subsequently used to measure ADA concentrations (lower limit quantification: &amp;lt;1.6 µg/mL) and antibody to adalimumab (ATA) status using a drug tolerant homogeneous mobility shift assay, and albumin. Apparent ADA CL (L/day) was calculated incorporating these measure parameters in a nonlinear mixed effect model with Bayesian priors (under steady state assumption) with dose and inter-dose interval with ATA and albumin as covariate. Rates of sustained clinical and biochemical remission (Harvey Bradshaw Index (HBI) score consistently &amp;lt;5 and CRP levels consistently &amp;lt;3 mg/L) were estimated for each patient. Longitudinal changes in PK parameters within-and-across cycles were evaluated using intra-patient coefficient of variation and linear mixed effect models. Results Sera was available from 70 study visits in 12 patients (6 males, mean age 36 years). Median ADA concentrations and CL were 8 µg/mL (IQR 6.0-10.4) and 0.374 L/day (IQR 0.29-0.43), respectively, with ATA detected in one patient (#9). Estimated ADA concentrations and CL is presented in the Table. Intra-patient variability in CL was much lower across the two 14-day cycle (9% and 7%, respectively) compared to intra-patient variability in ADA concentration (15% and 13%, respectively). Linear mixed effect models confirmed these findings with no impact of sampling time on CL (intercept=0.46±0.12 L/day; slope estimate=0.002±0.002 L/day; p=0.16) as compared to significant change in ADA concentrations (intercept=10.6±1.2 µg/mL; slope estimate=-0.25±0.03 µg/mL; p&amp;lt;0.01) over inter-dose interval sampling time. Sustained clinical and biochemical remission was achieved in 5/12 patients (42%); none presented with CL &amp;gt;0.8 L/day (a cut-off previously associated with worse outcomes). Of 7 patients without sustained clinical and biochemical remission, two presented with optimal concentrations (&amp;gt; 10 µg/mL), thus suggestive of mechanistic failure, and one developed ATA, lower concentration and higher ADA CL. Conclusion CL is subject to less intra-patient variability than ADA concentrations, supporting its assessment at any time point within a 14-day treatment cycle.

BNT321, a novel monoclonal antibody targeting sialyl Lewis A: Phase 1 monotherapy and combination with mFOLFIRINOX in patients with advanced CA19-9 expressing cancers.

654 Background: BNT321 is a high affinity human monoclonal antibody targeting the sialyl Lewis A epitope of CA19-9. This Phase 1/1b dose escalation/expansion study investigated BNT321 as monotherapy and in combination with mFOLFIRINOX (mFFX) in patients (pts) with advanced CA19-9 expressing cancers. Methods: Eligible pts: progressive CA19-9 expressing solid tumors, liver transaminases ≤ 2 x ULN, bilirubin WNL, ECOG PS 0-1. BNT321 given on Qwk, Q2wk, and Q4wk schedules. Lead in dose (1 mg/kg given 1 wk prior to assigned dose) evaluated on Q2wk + Q4wk schedules. BNT321 + mFFX given Q2wk as 1L or 2L metastatic therapy (1L+2L met). Dexamethasone given as premedication. Endpoints: safety, MTD, RP2D, efficacy, PK, changes in serum CA19-9. Results: 82 pts received BNT321 monotherapy and 15 received BNT321 + mFFX. BNT321 monotherapy MTD was 2 mg/kg Q2wk and MTD with mFFX was 1 mg/kg. Schedule and lead in dose did not significantly alter MTD. Dose limiting toxicities (DLTs) for BNT321 monotherapy and with mFFX were elevations in hepatic AST and ALT with or without bilirubin elevations. These events generally occurred early (cycle 1), resolved with drug hold, and did not preclude subsequent reduced dose BNT321. Frequent related AEs (total %/ &gt; grade 3 %) for BNT321 include increased ALT (39%/19%), AST (35%/12%), T bilirubin (27%/9%), fatigue (21%/0%), infusion related reaction (IRR) (17%/1%) and for BNT321 + mFFX fatigue (67%/0%), increased AST (40%/27%), ALT (33%/20%), diarrhea (33%/0%), nausea (20%/0%). At combination MTD (n=7): fatigue (71%/0%), diarrhea (29%/0%), IRR (29%/0%), nausea (28%/0%), increased AST (14%/14%), ALT (14%/14%). BNT321 demonstrated a T1/2 of 11.75 days + dose proportional Cmax and AUC with intra-patient variability. Enhanced clearance observed among pts with higher baseline (BL) serum CA19-9. For BNT321 monotherapy stable disease (RECIST 1.1) was best response, with time on study &gt; 90 days and &gt; 180 days in &gt; 20% and 10% of pts, respectively. Correlation between time on study and post BL normalization of CA19-9 was observed. For BNT321 + mFFX (1L+2L met), PRs were observed in 3/11 (27%) response evaluable pts who had time on study 10.0-15.8 months. Conclusions: BNT321 and BNT321 + mFFX MTDs were 2 mg/kg and 1 kg/kg, respectively. DLTs were hepatic AST, ALT and T bilirubin elevations which were generally cycle 1 and did not preclude subsequent BNT321 at reduced dose. BNT321 monotherapy resulted in disease stabilization and prolonged time on study (&gt; 90 days for &gt; 20%) in pts with advanced line, metastatic PDAC and other CA19-9+ cancers. BNT321 significantly decreased CA19-9 in the majority of pts and PK was similar to other human monoclonal antibodies. BNT321 + mFFX (1L+2L met) demonstrated multicycle tolerability and a 27% PR rate with 10+ months duration on study. BNT321 + mFFX is being evaluated in resected PDAC in the adjuvant setting. Clinical trial information: NCT02672917 .

Therapeutic drug monitoring of corticosteroids/β2-agonists in the hair of patients with asthma: an open-label feasibility study.

Background: Although adherence to inhaled medication is critically important for treatment efficiency, around half of patients taking these drugs are non-adherent or make critical errors when using their delivery device. Segmental hair analysis might be a valuable tool for therapeutic monitoring because hair concentrations reflect exposure from month to month. The objective of the present proof-of-concept study was to establish the feasibility of segmental hair analysis of inhaled budesonide and formoterol in asthma patients. Methods: We conducted a prospective, open-label, interventional study of adult patients being treated with budesonide/formoterol for controlled, moderate-to-severe asthma (CorticHair, NCT03691961). Asthma control, lung function, and medication adherence were recorded. Hair samples were taken 4 months after enrolment and cut into four 1cm segments. Results: Samples were available from 21 patients (20 women; median age: 53; median budesonide dose: 600μg/d). Budesonide and formoterol were detected in samples from 18 to 13 patients, respectively. The median hair concentrations were 6.25pg/mg for budesonide and 0.9pg/mg for formoterol. The intrapatient coefficient of variation between hair segments was 21% for budesonide and 40% for formoterol. Pearson's coefficients for the correlations between the hair concentration and the self-reported drug dose and the prescribed drug dose were respectively 0.42 (p = 0.08) and 0.29 (p = 0.25) for budesonide and 0.24 (p = 0.44) and 0.17 (p = 0.57) for formoterol. Conclusion: Segmental hair analysis of inhaled medications was feasible, with low intrapatient variability. This innovative, non-invasive means of assessing monthly drug exposure might help physicians to personalize drug regimens for patients with difficult-to-treat asthma.