Citations

We consider the problem of reducing the time that healthcare professionals need to understand the patient’s medical history through the next generation of biomedical decision support. This problem is societally important because it has the potential to improve healthcare quality and patient outcomes. However, navigating electronic health records (EHR) is challenging due to high patient-doctor ratios, potentially long medical histories, urgency of treatment for some medical conditions, and patient variability. The current EHR systems provide only a longitudinal view of patient medical history, which is time-consuming to browse, and doctors often need to engage nurses, residents, and others for initial analysis. To overcome this limitation, we envision an alternative spatial representation of patient histories (e.g., electronic health records) and other biomedical data in the form of Atlas-EHR. Just like Google Maps, which allows a global, national, regional, and local view, Atlas-EHR can start with an overview of the patient’s anatomy and history before drilling down to spatially anatomical subsystems, their individual components, or subcomponents. Atlas-EHR presents a compelling opportunity for spatial computing since healthcare is almost a fifth of the US economy. However, traditional spatial computing designed for geographic use cases (e.g., navigation, land survey, and mapping) faces many hurdles in the biomedical domain. This article presents several open research questions under this theme in five broad areas of spatial computing.

CD36 expression in both immune and non-immune cells is known to be directly involved in cancer metastasis. Extracellular vesicles (EVs) secreted by malignant melanocytes play a vital role in developing tumor-promoting microenvironments, but it is unclear whether this is mediated through CD36. To understand the role of CD36 in melanoma, we first analyzed the SKCM dataset for clinical prognosis, evaluated the percentage of CD36 in lymphatic fluid-derived EVs (LEVs), and tested whether melanoma-derived EVs increase CD36 expression and induce M2-macrophage-like characteristics. Furthermore, we performed a multiplex immunofluorescence (MxIF) imaging analysis to evaluate the CD36 expression and its colocalization with various other cells in the lymph node (LN) of patients and control subjects. Our findings show that cutaneous melanoma patients have a worse clinical prognosis with high CD36 levels, and a higher percentage of CD36 in total LEVs were found at baseline in melanoma patients compared to control. We also found that monocytic and endothelial cells treated with melanoma EVs expressed more CD36 than untreated cells. Furthermore, melanoma-derived EVs can regulate immunosuppressive macrophage-like characteristics by upregulating CD36. The spatial imaging data show that cells in tumor-involved sentinel LNs exhibit a higher probability of CD36 expression than cells from control LNs, but this was not statistically significant. Conclusively, our findings demonstrated that CD36 plays a vital role in controlling the immunosuppressive microenvironment in the LN, which can promote the formation of a protumorigenic niche.

e21554 Background: Pregnancy associated melanoma (PAM) occurs in 1% of female patients with melanoma and affects 1 in 2200 pregnancies. Antepartum evaluation of melanoma must incorporate both maternal and fetal factors, and currently there is lack of standardization. Our study aimed to review the incidence of antepartum melanoma at our institution and highlight patterns in management and treatment during this high-risk scenario. Methods: After IRB approval, the Mayo Clinic electronic medical record was searched with key words “melanoma” and “pregnancy”. 25 patients with melanoma during pregnancy were identified from 1987-2023. 6 patients were excluded as skin changes noted during pregnancy were not formally diagnosed as melanoma until after delivery. Abstracted data included demographic information, disease characteristics, staging (per AJCC guidelines at time of diagnosis), and clinical outcomes. Survival data were calculated. Results: 19 patients were included. Diagnosis occurred at an average maternal age of 30 years (range 24-38 years) and a mean gestational age of 20 weeks (range 6-35 weeks). All patients had a term delivery. 4 patients underwent labor induction at 37 weeks for staging/treatment. 60% of patients had a delay in imaging or treatment attributed to pregnancy, including 1 patient who was upstaged with metastatic disease based on postpartum imaging. 82% of stage I-III patients underwent wide local excision during pregnancy; however, 35% of sentinel lymph node sampling was delayed until postpartum. 3 stage II/III patients received adjuvant therapy (interferon or sargramostim) after delivery. Adjuvant immunotherapy was discussed with 2 patients in the postpartum period but ultimately not given due to the time lapse between surgery and delivery. 1 patient with stage IV disease diagnosed at a gestational age of 20 weeks was evaluated with MRI PET scan then treated with vemurafenib monotherapy during pregnancy. Workup and outcomes were reviewed by stage (Table 1). 7 of 19 patients had subsequent pregnancies, and 1 had recurrence of melanoma during a second pregnancy (stage II followed by stage IV). Due to a low number of censoring events, median progression free survival and overall survival were not reached. Conclusions: Melanoma diagnosed during pregnancy can be safely and effectively staged with sentinel lymph node surgery, MRI imaging (PET-MRI vs standard), and CT imaging with shielding without a need for early induction of labor nor a delay in cancer care. Furthermore, we report a patient with stage IV disease treated with vemurafenib during and immunotherapy after pregnancy, indicating that treating stage IV PAM with systemic therapy is a consideration. [Table: see text]

e23270 Background: Melanoma is the most lethal form of skin cancer which have seen drastic improvement in patient survival over the last decade. BRAF is the most common driver mutation in melanoma, seen in ≈50% of all patients (≈30% of patients > 65). The use of BRAF & MEK inhibitors yields high response rates, though it is limited by toxicity and development of acquired resistance. Acknowledging these limitations, we aimed at assessing the efficacy and toxicity of these agents in melanoma patients > 65. Methods: We identified electronic medical records of all melanoma patients > 65 that were treated with BRAF & MEK inhibitors at our institution over the years 2017-2023. Data was retrospectively collected including demographics, disease characteristics, treatment given, response patterns and toxicity. Results: 106 patients were identified. The median age was 71 (65-89), 55% were males. The median follow up was 28.9 months. 32 (30%) patients were treated at first line, 58 (55%) at second line and 16 (15%) at third line. 88 (83%) evaluable patients received treatment for unresectable/metastatic disease of which 84% had an objective response (60% partial response, 24% complete response). Response rate (RR) was 82%, 85% and 87% for first, second and third line respectively. RR was 86% for patients with an increased serum lactate dehydrogenase. 33% of patients had active central nervous system (CNS) metastases at treatment initiation, for whom the systemic RR was 80% and the CNS RR was 39%. The median progression free survival (PFS) was 7.9 months, with a PFS of 6, 8.3 and 13.4 months for first, second and third line respectively. The median PFS was 5.7 months for patients with active CNS disease. The median overall survival (OS) from treatment initiation was 15.7 months (12.5, 14.5, 31.9 for first, second & third line respectively). The median OS for patients with CNS disease was 9.8 months. 16 patients were treated in the adjuvant setting, of which 6 (37%) finished treatment as planned, 3 stopped due to disease progression (19%) and 6 stopped due to toxicity (37%). 88% of patients experienced adverse events (AEs) of any grade, with 27% having grade 3-4 toxicity. There were no grade 5 toxicities reported. 36% of patients experienced one AE, while 52% experienced two or more. 21% of patients stopped treatment due to toxicity, 28% needed a dose reduction and 20% changed to different BRAF/MEK inhibitors. 10% of patients needed systemic corticosteroids to treat AEs. The most common toxicities seen were fever (30%), fatigue (30%), skin rash (22%), elevated liver function tests (20%), arthralgia/myalgia (15%), nausea (14%) and diarrhea (11%). 7% had decrease in cardiac ejection fraction with one grade 3 leading to treatment discontinuation. Conclusions: Treatment with BRAF & MEK inhibitors is challenging in older patients, with a high prevalence of toxicity leading to treatment modifications and discontinuation. Efficacy seems to be the same as in the general population.

e23269 Background: Most cases of malignant melanoma are cutaneous, with ≈50% having a BRAF driver mutation that predicts response to MAPK pathway inhibitors. A small minority of melanoma cases harbor an activating KIT mutation, most notably in mucosal and acral melanomas (15-20%) and occasionally in those arising from chronic sun-damaged skin (2-3%). Only about a third of KIT mutated melanomas respond to targeted therapy with Imatinib, yet data is scarce and limited, especially in older patients. We sought to characterize the efficacy and toxicity of Imatinib in KIT-mutated melanoma patients over 65. Methods: We identified electronic medical records of patients over 65 that were treated with Imatinib for KIT mutated melanoma at our institution over the years 2017-2023. Data was retrospectively collected including demographics, disease characteristics, response patterns and toxicity. Results: 10 patients were identified, 50% were males. The median age at treatment initiation was 75 years (71-100). 3 patients had cutaneous primary, 3 had Vulvar/vaginal primary, 3 had acral primary and 1 had anal canal primary. All patients had normal Lactate dehydrogenase at treatment initiation and ECOG performance status was 0-2 (median 0). 9 patients received Imatinib for stage IV disease with an overall response rate (ORR) of 55% (44% partial response, 11% complete response). Median duration of response was 4 months. Responses were seen in acral melanoma (67%), vulvar/vaginal melanoma (67%) and cutaneous melanoma (33%). Median Progression free survival was 4.3 months (1.8-44), median overall survival from treatment initiation was 22.6 months (4-64). 6 patients were treated as 2nd line with an ORR of 67% and 3 were treated as 3rd line with an ORR of 33%. There was one patient with M1d disease who did not respond to treatment either systematically or intracranially. 6 patients had Exon 11 mutations (V560D/G/E, N564S and L576P) of which 4 responded (67%). 2 had Exon 17 mutations (N822C/K) of which 1 responded (50%) and the 2 others had an Exon 14 (F681I) and Exon 13 (K642E) mutation that did not respond to treatment at all. Toxicity was moderate with 90% of patients experiencing any grade AE, yet only 1 experienced toxicity requiring dose interruption with two Grade 3 toxicities - Pneumonitis and decreased neutrophil count, leading to temporary treatment interruption, dose reduction and a course of corticosteroids. The rest of the patients experienced only Grade 1-2 toxicity. 4 patients needed dose reductions, there were no treatment discontinuations due to toxicity. Conclusions: Treatment with Imatinib for elderly KIT mutated melanoma patients is safe and well tolerated with no treatment discontinuations recorded. The response rate is encouraging yet seems to vary according to the KIT mutation present as previously reported. The duration of response is usually short-lived and alternative/combination treatments are still needed for this patient population.

Abstract Background: The prognosis of patients with MM with CNS mets is poor. E6201 is an intravenous (IV) MEK inhibitor with activity against BRAF V600-mutated MM cell lines, including MAPK resistance alteration. A previous phase I trial demonstrated activity of E6201 in BRAF V600E mutated MM with a Maximal Tolerated Dose of 320mg/m2 given IV once a week x 3 weeks q 28 days. 2/23 (8.7%) of patients had a PR, 8/23 (34.8%) had SD. Two patients with MM and brain mets achieved near-CR which led to preclinical studies that demonstrated E6201 is unaffected by P-gp and BCRP transport and achieved higher brain to blood concentration (266%).In this trial, patients with BRAF mutation + MM with brain mets, single agent E6201 given at 320mg/m2 twice weekly x 3 weeks q 28 days was determined to be safe. One patient had CNS SD and a PR in lung mets, and a second patient achieved CNS stable disease and CR in a leg melanotic lesion. The drug was well-tolerated with one reversible AE thrombocytopenia (Gr 2). The final review showed intracranial response of SD in 2/4 (50%) patients and systemic SD in 3/4 (75%) patients. Methods: We are currently accruing to the dose escalation cohort of E6201 with dabrafenib 150 mg twice daily orally (n=up to 22 evaluable patients). E6201 is administered IV at 320mg/m2 twice weekly for 3 weeks every 28 days. Patients must have stage IV melanoma with BRAF mutation with at least one active lesion in the brain. Prior local therapy is allowed if done at least 3 weeks prior to cycle 1. Participants must be on a stable dose of steroids for at least 7 days and have an ECOG <!–=2. The study allows one prior BRAF/MEK inhibitor therapy. The primary objectives are to determine the MTD of E6201 when combined with dabrafenib and the response rate of brain mets. The secondary objectives include duration of response, extracranial response, progression free survival, overall survival, and impact of BRAF mutation subtype and safety of the combination. Clinicaltrials.gov: NCT05388877 References:1.Gampa G, et al. Brain distribution of a novel MEK inhibitor E6201: implications in the treatment of melanoma brain metastases. 2018. Drug Metab Dispos.2.Tibes R et al. Safety, pharmacokinetics, and preliminary efficacy of E6201 in patients with advanced solid tumors, including melanoma: results of a phase I study. 2018. Brit J of Cancer. 3.Babiker Gm et al, E6201, an intravenous MEK1 inhibitor, achieves an exceptional response in BRAF V600E mutated metastatic malignant melanoma with brain metastases. 2018. Inv New Drugs4.Gampa G, Kim M, Cook-Rostie N, Laramy JK, Sarkaria JN, Paradiso L, DePalatis L, Elmquist WF. Brain distribution of a novel MEK inhibitor E6201: Implications in the treatment of melanoma brain metastases. 2018. Drug Met Disp.–> Citation Format: Mahesh Seetharam, Roxana Dronca, Arkadiusz Z. Dudek, Garth Nelson, Matthew Block, Skylar Starling, Amber Baskin, Renee Bradshaw, Courtney Nelson, Kylee Andrews, Alisha Birgin, Cristina Watson, Yiyi Yan, Daruka Mahadevan, Svetomir Markovic, Tom Myers, Linda Paradiso, Hani Babiker. Phase 1 trial of MEK1 inhibitor E6201 plus dabrafenib in patients (pts) with BRAF V600-mutated metastatic melanoma (MM) with central nervous system (CNS) metastases (mets) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT157.

Abstract Purpose: AB160 is a 160-nm nano-immunoconjugate consisting of nab-paclitaxel (ABX) nanoparticles noncovalently coated with bevacizumab (BEV) for targeted delivery into tissues expressing high levels of VEGF. Preclinical data showed that AB160 resulted in greater tumor targeting and tumor inhibition compared with sequential treatment with ABX then BEV. Given individual drug activity, we investigated the safety and toxicity of AB160 in patients with gynecologic cancers. Patients and Methods: A 3+3 phase I trial was conducted with three potential dose levels in patients with previously treated endometrial, cervical, and platinum-resistant ovarian cancer to ascertain the recommended phase II dose (RP2D). AB160 was administered intravenously on days 1, 8, and 15 of a 28-day cycle (ABX 75–175 mg/m2, BEV 30–70 mg/m2). Pharmacokinetic analyses were performed. Results: No dose-limiting toxicities (DLT) were seen among the three dose levels tested. Grade 3/4 toxicities included neutropenia, thromboembolic events, and leukopenia. DL2 (ABX 150 mg/m2, BEV 60 mg/m2) was chosen as the RP2D. Seven of the 19 patients with measurable disease (36.8%) had confirmed partial responses (95% confidence interval, 16.3%–61.6%). Pharmacokinetic analyses demonstrated that AB160 allowed 50% higher paclitaxel dosing and that paclitaxel clearance mirrored that of therapeutic antibodies. Conclusions: The safety profile and clinical activity of AB160 supports further clinical testing in patients with gynecologic cancers; the RP2D is DL2 (ABX 150 mg/m2, BEV 60 mg/m2).

Abstract Background: Neuropilin 2 (NRP2) is a co-receptor that enhances signaling of growth factor and cytokine receptors and is expressed in tumor and microenvironment (TME) cells in melanoma and other tumors. Neuropilin 2 expression in tumor cells is associated with more aggressive tumors. Expression in tumor associated macrophages enhances efferocytosis and immunologically silent tumor cell death. Methods: Whole excisional lymph node biopsies were obtained from 10 treatment naïve patients with metastatic cutaneous melanoma who subsequently received anti-PD1 treatment. A single 5mm formalin-fixed paraffin embedded tissue section was used to assess a panel of 39 analytes by cyclic multiplex immunofluorescence (MxIF). Fields of view (~1mm2, n=288) were selected from pathologist-annotated regions of the tumor core, tumor-immune interface and adjacent lymphoid tissue. Pixel-based single cell segmentation and a supervised classifier approach was applied to resolve 12 distinct tumor, stromal and immune cell phenotypes and functional states (NRP2 positive or negative) in 1.5 million cells. Results: Tumor recurrence was observed in 6 patients (relapsed), whereas 4 patients were recurrence-free (non-relapsed) during follow up. Among the different cell types, NRP2 expression was more frequent in macrophages (44%), tumor cells (40%), dendritic cells (40%), followed by Tregs (31%) and T helper cells (29%), and less frequent in neutrophils (24%), cytotoxic T cells (23%) and B cells (15%). In colocalization permutation analysis, NRP2 expressing macrophages clustered away from tumor cells in non-relapsed patients while a random spatial distribution of NRP2 expressing macrophages with respect to tumor cells was observed in relapsed patients. In comparing the odds of tumor cell interactions with NRP2-expressing macrophages to those with NRP2 non-expressing macrophages, we found in the tumor:stromal interface (10% tumor cells) that cells from both non-relapsed and relapsed patients were more likely to interact with NRP2 non-expressing macrophages (OR = 0.73, 95% CI = [0.71, 0.75] and OR = 0.56, 95% CI = [0.55, 0.58] for non-relapsed and relapsed patients, respectively). However, in the tumor core (90% tumor cells), tumor cells from relapsed patients had significantly higher odds of interacting with NRP2 expressing macrophages, (OR = 1.15, 95% CI = [1.12, 1.18]), and this was not seen for non-relapsed patients (OR = 0.68, 95% CI = [0.66, 0.71]). In FOVs dominated by tumor cells (75% tumor), tumor cells from relapsed patients had 4.97 times the odds of expressing NRP2 compared to tumor cells from non-relapsed patients (95% CI = [2.23, 11.09], p = 0.0001). Conclusions: These spatial analytics suggest complex interactions among NRP2 expression in tumor and TME of melanoma determining risk for relapse with anti-PD1 treatment. Citation Format: Anastasios Dimou, Raymond M. Moore, Caitlin Ward, Alexey Leontovich, Ruifeng Guo, Chen Wang, Shankar Suman, Betty Dicke, Jill M. Schimke, Noah A. Stueven, Chathu A. Atherton, Wendy Nevala, Svetomir N. Markovic. Spatial analysis of neuropilin 2 expression in the microenvironment of melanoma [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 2905.