Citations

8071 Background: Data from the PACIFIC study demonstrated a 5-yr median progression free survival (PFS) and overall survival (OS) of 16.9 and 47.5 months respectively for patients with stage 3A and stage 3B NSCLC demonstrating a high risk of relapse. The 8th ed. of the IASLC staging project reports that the 60-month OS for stage 3A, B and C disease is 41%, 24% and 12% respectively, indicating that improved treatment options are needed for this patient population. Induction chemo-IO (ID chemo-IO) followed by concurrent chemo-radiation (CRT) has not been fully investigated due to concerns regarding the toxicity profile, but this may representant an important unexplored avenue for research. We aim to describe the outcomes of patients who received ID chemo-IO followed by CRT with or without maintenance IO. Methods: We conducted a retrospective study across all Mayo Clinic sites. Patients were included if they were diagnosed with Stage 3 NSCLC deemed ineligible for resection and/or requiring raditation over a large-field ] by a multidisciplinary team with plans for ID chemo-IO prior to CRT and maintenance IO. A total of 927 cases of stage 3 NSCLC patients were screened and those receiving ID chemo-IO followed by CRT were extracted (n = 36). Clinical endpoints are PFS, OS, overall response rate (ORR) and treatment related adverse events (TrAE) defined using CTCAE 5.0. Results: The median age was 67 years, 52.8% were female, all patients were past smokers and 97.2% identified as white. The tumor histologies were adenocarcinoma (66.67%), squamous (27.8%), mucinous adenocarcinoma (2.8%) and sarcomatoid (2.8%). Majority were Stage 3B (47.2%) followed by 3C (38.9%) and 3A (13.9%). N2 and N3 disease was noted in 36.1% and 55.6% of patients respectively. PD-L1 by IHC was > 1-49% (47.2%), > 50% (22.2%) and < 1% (19.4%). Patients received ID chemo-IO with pembrolizumab (83.3%), nivolumab (11.1%) and atezolizumab (2.78%). Average number of ID chemo-IO cycles were 3.67 cycles. The ORR to ID chemo-IO was 86.11%. The median PFS was 23.67 mths and the median OS was 32.07 months. About 94% of patients received CRT afterwards and 66.67% received maintenance IO with pembrolizumab (53.17%) or durvalumab (45.83%). Any grade TrAE occured in 58.33% of patients. Pneumonitis was the most common event (38.9%). Grade 3 -4 pneumonitis was noted in 28.5% (4/11) patients. Other toxicities included hepatitis (8.3%), colitis (11.1%) and myasthenia gravis (2.8%) and 22% of these TrAE’s were grade 3 or 4. Conclusions: Our results indicate that ID chemo-IO shows promise as a therapeutic approach for patients with unresectable stage III NSCLC, especially for patients deemed ineligible or high risk for upfront radiation. Further investigation is needed through a randomized clinical trial to systematically explore and validate the safety and efficacy of ID chemo-IO.

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.

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.

ABSTRACT Despite ocular adverse events from immune checkpoint inhibitors being uncommon, they are still important complications to be aware of. We present the case of metastatic melanoma on ipilimumab/nivolumab in a patient who developed immunotherapy complications with delayed diagnosis because the only presenting symptom was unilateral ptosis. We reviewed the literature for relevant and important ocular and neurological complications of immune checkpoint inhibitors.

Abstract Advances in genetic technology have led to the increasing use of genomic panels in precision oncology practice, with panels ranging from a couple to hundreds of genes. However, the clinical utilization and utility of oncology genomic panels, especially among vulnerable populations, is unclear. We examined the association of panel size with socioeconomic status and clinical trial matching. We retrospectively identified 9,886 eligible adult subjects in the Mayo Clinic Health System who underwent genomic testing between January 1, 2016 and June 30, 2020. Patient data were retrieved from structured and unstructured data sources of institutional collections, including cancer registries, clinical data warehouses, and clinical notes. Socioeconomic surrogates were approximated using the Area Deprivation Index (ADI) corresponding to primary residence addresses. Logistic regression was performed to analyze relationships between ADI or rural/urban status and (i) use of genomic test by panel size; (ii) clinical trial matching status. Compared with patients from the most affluent areas, patients had a lower odds of receiving a panel test (vs. a single-gene test) if from areas of higher socioeconomic deprivation [OR (95% confidence interval (CI): 0.71 (0.61–0.83), P &lt; 0.01] or a rural area [OR (95% CI): 0.85 (0.76–0.96), P &lt; 0.01]. Patients in areas of higher socioeconomic deprivation were less likely to be matched to clinical trials if receiving medium panel tests [(OR) (95% CI): 0.69 (0.49–0.97), P = 0.03]; however, there was no difference among patients receiving large panel tests (P &gt; 0.05) and rural patients were almost 2x greater odds of being matched if receiving a large panel test [(OR) (95% CI): 1.76 (1.21–2.55), P &lt; 0.01]. Significance: We identified socioeconomic and rurality disparities in the use of genomic tests and trial matching by panel size, which may have implications for equal access to targeted therapies. The lack of association between large panel tests and clinical trial matching by socioeconomic status, suggests a potential health equity impact, while removing barriers in access to large panels for rural patients may improve access to trials. However, further research is needed.

ABSTRACT Introduction Proton craniospinal irradiation (pCSI) is a treatment option for leptomeningeal disease (LMD), which permits whole neuroaxis treatment while minimizing toxicity. Despite this, patients inevitably experience progression. Adding systemic therapy to pCSI may improve outcomes. Methods In this single-institution retrospective case series, we present the feasibility of treatment with pCSI (30Gy, 10 fractions) and an immune checkpoint inhibitor (ICI) in two sequential patients with LMD from melanoma. Results The first patient developed LMD related to BRAF V600E-mutant melanoma after prior ICI and BRAF-targeted therapy. After pCSI with concurrent nivolumab, the addition of relatlimab, and BRAF-targeted therapy, he remained alive 7 months after LMD diagnosis despite central nervous system progression. The second patient developed LMD related to BRAF-wildtype melanoma after up-front ICI. He received pCSI with concurrent ipilimumab and nivolumab, then nivolumab maintenance. Though therapy was held for ICI hepatitis, the patient remained progression-free 5 months after LMD diagnosis. Conclusion Adding an ICI to pCSI is feasible for patients with LMD and demonstrates a tolerable toxicity profile. While prospective evaluation is ultimately warranted, pCSI with ICI may confer survival benefits, even after prior ICI.

Summary HLA evolutionary divergence reflects the ability to recognize diverse neoantigens as non-self, and as a biomarker is conceptually distinct from programmed cell death ligand 1 expression and tumor mutation burden. HLA-based assays to predict benefit from immunotherapy in lung cancer require prospective validation. See related article by Jiang et al., p. 4830

AbstractBackgroundThe vast majority of patients with ROS1 positive non‐small cell lung cancer (NSCLC) derive clinical benefit from currently approved ROS1 therapies, including crizotinib and entrectinib. However, a small proportion of patients treated with ROS1 inhibitors fail to derive any clinical benefit and demonstrate rapid disease progression. The biological mechanisms underpinning intrinsic resistance remain poorly understood for oncogene‐driven cancers.MethodsWe generated a patient‐derived cell line, CUTO33, from a ROS1 therapy naive patient with CD74‐ROS1+ NSCLC, who ultimately did not respond to a ROS1 inhibitor. We evaluated a panel of ROS1+ patient‐derived NSCLC cell lines and used cell‐based assays to determine the mechanism of intrinsic resistance to ROS1 therapy.ResultsThe CUTO33 cell line expressed the CD74‐ROS1 gene fusion at the RNA and protein level. The ROS1 fusion protein was phosphorylated at baseline consistent with the known intrinsic activity of this oncogene. ROS1 phosphorylation could be inhibited using a wide array of ROS1 inhibitors, however these inhibitors did not block cell proliferation, confirming intrinsic resistance in this model and consistent with the patient's lack of response to a ROS1 inhibitor. CUTO33 expressed high levels of AXL, which has been associated with drug resistance. Combination of an AXL inhibitor or AXL knockdown with a ROS1 inhibitor partially reversed resistance.ConclusionsIn summary, we demonstrate that AXL overexpression is a mechanism of intrinsic resistance to ROS1 inhibitors.