Doonan, Bently P.

Importance There is no consensus on staging and surveillance imaging for cutaneous squamous cell carcinoma (CSCC). Although imaging has been shown to affect management, broad recommendations from the National Comprehensive Cancer Network have led to variability in clinical practice. Objective To develop multidisciplinary consensus recommendations on the use of staging and surveillance imaging of localized CSCC. Evidence Review A multidisciplinary expert panel across academic and clinical practice settings convened a Delphi consensus, with 3 iterative survey rounds from January to June 2025. Data were analyzed from February 2025 to January 2026. Eligibility defined by at least 1 to 2 CSCC publications during the previous 5 years, involvement in a relevant clinical trial, experience treating at least 3 patients monthly with CSCC, and/or 5 years or longer of clinical practice. Fifty-four experts were invited and 45 (83%) completed all 3 rounds and were included in the final analysis. Structured Delphi surveys evaluated clinical scenarios, imaging modalities, and surveillance strategies for CSCC. Consensus and near-consensus recommendations were generated, defined as 80% or greater and 70% to 79% agreement, respectively. Findings The 45 participants (21 female individuals [47%] and 24 male individuals [53%]; 14 Asian individuals [31%], 1 multiracial individual [2%], and 30 White individuals [67%]) consisted of dermatology (15 [33%]), medical oncology (7 [16%]), radiation oncology (9 [20%]), radiology (9 [20%]), surgery (3 [7%]), and otolaryngology specialists (2 [4%]). The Delphi panel recommended staging and surveillance for CSCCs with at least a 15% risk of metastasis. Consensus or near consensus was reached to recommend staging and surveillance imaging for tumors with a concern for metastasis, bone invasion, invasion beyond subcutaneous fat, large-caliber nerve invasion, or a diameter of 4 cm or larger or the combination of tumors with poorly differentiated histology and any of the following: diameter of 2 cm or larger, lymphovascular invasion and subcutaneous fat invasion, or lymphovascular invasion and small-caliber perineural invasion. Computed tomography imaging was the preferred modality for nodal staging (38 [84%]) and surveillance (35 [78%]). For surveillance duration, consensus was reached to provide imaging for at least 2 years, and near consensus was reached for at least 3 years. Conclusions and Relevance This study provides an expert consensus–based framework to standardize imaging in localized CSCC that may inform future guidelines.

Abstract Current advances in the treatment of melanoma brain metastases through immune checkpoint blockade and targeted therapy has significantly improved outcomes and patient survival. Yet, half of all patients continue to die from brain metastases despite use of these therapies and the addition of localized therapies like surgery and stereotactic radiosurgery. Novel treatments are needed to improve the morbidity and mortality associated with melanoma brain metastases. We have identified the inflammatory myddosomal pathway as a novel potential target of therapy in melanoma brain metastases, with gross upregulation in both tumor tissue and tumor-infiltrating immune cells. These cells display upregulation in MYD88, IRAK-1, IRAK-4, and downstream mediators of inflammatory activation at both the gene and protein level. We have previously shown the ability of the oral IRAK-4 inhibitor emavusertib (CA-4948) to penetrate the blood brain barrier and inhibit the myddosomal pathway in metastatic melanoma and primary CNS lymphoma. In this study we further show the capacity for IRAK-4 inhibition with emavusertib to improve the therapeutic efficacy of anti-PD-1 immune checkpoint blockade in melanoma brain metastases. Emavusertib in combination with anti-PD-1 therapy results in improved tumor-infiltrating lymphocyte recruitment, decreased myeloid derived suppressor cell function, and upregulation of interferon γ signaling resulting in improved survival in aggressive mouse models of melanoma brain metastases. This work supports the development of combination strategies of emavusertib with immune checkpoint blockade in melanoma brain metastases.

Background/Objectives: Tumor-infiltrating lymphocyte (TIL) therapy is an important option for patients with metastatic melanoma progressing after standard systemic therapy, but real-world data on treatment delivery, toxicity monitoring, and immune recovery remain limited. We evaluated clinical outcomes, treatment tolerance, immune reconstitution, and cardiac biomarker dynamics across three Mayo Clinic sites. Methods: We retrospectively analyzed adults with metastatic melanoma who received lymphodepleting chemotherapy followed by TIL infusion and high-dose interleukin-2 (IL-2) between April 2024 and December 2025. Clinical outcomes, treatment delivery, and adverse events were assessed. Longitudinal immune monitoring included CD4 and CD8 T-cell counts, CD4:CD8 ratio, and immunoglobulin G (IgG) at baseline and follow-up. In a prespecified cardiac sub-cohort, high-sensitivity troponin (hs-Tn) was measured during IL-2 administration to evaluate associations with cardiac events and IL-2 interruption. Results: Thirty-six patients underwent TIL infusion. The objective response rate was 50.0%, including complete responses in 13.9%, and the disease control rate was 72.2%. Median progression-free survival was 3.61 months, and median overall survival was 12.94 months. M1d disease was associated with inferior overall survival on univariable analysis (HR 6.55, 95% CI 2.03–21.17; p = 0.002), with attenuation after multivariable adjustment. Receipt of ≥3 IL-2 doses was associated with longer overall survival on univariable analysis (HR 0.20, 95% CI 0.06–0.64; p = 0.007), but this association also attenuated after adjustment. Longitudinal immune monitoring demonstrated persistent CD4 lymphopenia through 6 months, sustained inversion of the CD4:CD8 ratio, and declining IgG at months 3 and 6. In the cardiac sub-cohort (24 patients; 87 IL-2 doses), post-dose hs-Tn ≥15 ng/L was associated with clinically significant cardiac events (OR 9.6, 95% CI 1.5–60.6; p = 0.016) and IL-2 interruption (OR 3.4, 95% CI 1.1–10.7; p = 0.036). For cardiac events, hs-Tn ≥15 ng/L had 100% sensitivity and 100% negative predictive value. Conclusions: In routine practice, TIL therapy was feasible and active in metastatic melanoma. M1d disease identified a subgroup with poor survival, peri-dose hs-Tn showed promise as a tool to support safer IL-2 delivery, and prolonged CD4 suppression with IgG decline suggests that recovery after TIL therapy extends beyond initial hematologic reconstitution. These findings support prospective validation of biomarker-guided IL-2 monitoring and extended post-treatment immune surveillance.

e21521 Background: Outcomes following tumor-infiltrating lymphocyte (TIL) therapy vary in real-world practice, and accessible predictors are needed to inform patient selection and timing of referral. We evaluated whether baseline disease burden, metastatic distribution, and treatment delivery factors are associated with outcomes following TIL therapy. Methods: We retrospectively analyzed patients with metastatic melanoma treated with TIL therapy across Mayo Clinic sites (N = 27 infused). Baseline disease burden was characterized using AJCC metastatic stage and organ-specific involvement. A composite high visceral burden variable was defined as the presence of M1d disease and/or liver metastases. Bridging therapy use prior to infusion was recorded. Post-infusion IL-2 exposure was categorized as low (0-2 doses) vs. high (3-6 doses). Best overall response (BOR) was summarized using RECIST-based standard criteria. Overall survival (OS) and progression-free survival (PFS) were measured from TIL infusion and estimated using Kaplan–Meier methods with univariable Cox regression. Results: Median age at infusion was 62.0 years; 59.3% were male. Melanoma subtypes included cutaneous (81.5%) and mucosal (18.5%). Bridging therapy was used in 48.1%. Baseline metastatic stage was M1a/M1b in 18.5%, M1c in 63.0%, and M1d in 18.5%. Median follow up was 8.3 months. BOR included complete response (18.5%), partial response (37.0%), stable disease (22.2%), and progressive disease (22.2%), yielding an objective response rate of 55.6% and disease control rate of 77.8%. Patients with high visceral disease burden experienced inferior OS vs. those without high visceral burden (median 5.2 vs 13.4 months; HR 4.77, 95% CI 1.22–18.63; p = 0.014). Bridging therapy was not associated with OS or PFS. Higher post-infusion IL-2 exposure (seen in 77.8% of patients) was associated with improved OS (median 9.0 vs 3.7 months; HR 0.16, 95% CI 0.04–0.67, p = 0.005), likely reflecting early post-infusion clinical tolerance rather than a causal treatment effect. Median PFS for the cohort was 3.6 months and did not differ by IL-2 exposure ( p = 0.3), metastatic stage ( p = 0.8), bridging therapy ( p = 0.7), liver metastases ( p = 0.2), or LDH above upper limit of normal ( p = 0.1). Conclusions: The above findings are hypothesis generating and will support evaluation in larger cohort. In this real-world cohort of patients treated with TIL therapy, baseline visceral disease burden was strongly associated with survival outcomes, while bridging therapy did not compromise post-infusion efficacy among patients proceeding to infusion. Post-infusion IL-2 exposure correlated with OS and likely reflects early treatment tolerance. These readily available clinical features may inform patient counseling, referral timing, and sequencing decisions as TIL therapy enters broader clinical use.

9510 Background: Although acute toxicities associated with adoptive cellular therapy using lifileucel are well described and largely occur within the first 2 weeks of treatment, adverse events beyond this early window remain incompletely characterized. We sought to characterize treatment-related adverse events (AEs) with emphasis on those starting or persisting ≥2 weeks after lifileucel infusion. Methods: We conducted a retrospective multicenter study across three centers (Moffitt Cancer Center, Massachusetts General Hospital, and Mayo Clinic). Patients with advanced melanoma treated with lifileucel were included. The primary endpoint was incidence and characterization of AEs occurring or persisting ≥2 weeks after standard of care lifileucel infusion. Results: Among 79 patients (median follow-up 11 months [95% CI, 9.6–15]), median age was 63 years (range 30–79), 59% were male (n = 47), 41% were female (n = 32), and ECOG PS was 0–1 in 98%. Patients received a median of 5 IL-2 doses (range 0–6). Of 79 patients, 78 experienced treatment-related adverse events that either persisted or occurred >2 weeks after cell infusion. A total of 308 delayed treatment-related adverse events were identified; 96 were new events (31%) and 212 (69%) were continued toxicities that started < 2 weeks after cell infusion. Lymphopenia was the most common delayed or persistent toxicity, occurring in a majority of patients (n = 68/79, 86%). Treatment-associated anemia (n = 59/79, 75%), fatigue (n = 56/79, 71%) and thrombocytopenia (n = 24/79, 30%) were also common. Viral infections occurred in 9.0% (n = 7), including CMV/EBV viremia (n = 1) and respiratory or gastrointestinal viral infections (metapneumovirus, parainfluenza, SARS-CoV-2, and norovirus). Hemophagocytic lymphohistiocytosis (HLH) occurred in 2 patients (n = 2/79, 3%) and was fatal in both cases. No other toxicity related deaths were noted. Autoimmune toxicities directly attributable to TIL included vitiligo in 9% (n = 7; median onset 41 days), uveitis in 5% (n = 4; median onset 26 days), and sensorineural hearing loss in 1% (n = 1; onset 28 days). All patients underwent TIL infusion in the inpatient setting; a total of 14 of 79 patients (18%) were re-admitted after discharge due to treatment-related toxicity (median time from infusion 19 days). Conclusions: In this multicenter real-world cohort, toxicities persisting beyond two weeks were largely driven by lymphodepleting chemotherapy–associated immunosuppression and cytopenias. These findings highlight the importance of structured post-discharge monitoring and support ongoing efforts to de-intensify lymphodepleting chemotherapy to improve safety while maintaining clinical benefit.

ABSTRACT Primary cutaneous NUT adnexal carcinoma is an emerging provisional tumor entity characterized by NUTM1 rearrangement with fusion partners different from poroid neoplasms. These tumors should be distinguished from NUT carcinomas with a histopathologic appearance of poorly differentiated squamous cell carcinoma, which tend to behave more aggressively and demonstrate a widespread anatomic distribution. Since fewer than 20 cases of NUT adnexal carcinoma have been reported in the literature, we report herein another case to enhance our knowledge of the spectrum of clinical and pathologic features associated with this tumor. This case is characterized by an unusual clinical course. The lesion was present and slowly progressed over the course of 13 years prior to biopsy and excision. The tumor was composed of epithelial and myoepithelial elements with a range of features, including ductal, cribriform, and solid, with papillary, secretory, and keratocystic changes. The patient underwent wide local excision and sentinel lymph node biopsy, which revealed metastatic tumor. Molecular testing identified a BRD3‐NUTM1 fusion, confirming the diagnosis of NUT adnexal carcinoma. The patient remains disease‐free at 1‐year follow‐up without further therapy.

Localized cutaneous squamous cell carcinoma (cSCC) has a favorable prognosis, unlike advanced disease, especially with clinical perineural invasion (PNI), which poses substantial management challenges due to aggressivity and higher recurrence, metastasis, and mortality risks. PNI, a high-risk staging feature, has worse outcomes, particularly when clinically evident rather than incidental. Clinical PNI (cPNI) is evident by clinical symptoms (such as pain, paresthesia, or motor deficits) or radiologic findings, whereas incidental PNI (iPNI) is identified only histologically without associated symptoms or radiologic evidence. PNI remains a novel area with varying practice patterns across institutions. Improving risk stratification and tailoring multidisciplinary approaches are critical for optimizing outcomes. Our review outlines clinical practice patterns at our institution, providing insights into managing cSCC with PNI, focusing on diagnosis, imaging, staging, and emerging immunotherapies. A structured search was conducted using the terms “perineural invasion,” “cutaneous squamous cell carcinoma,” and “immunotherapy.” cPNI has a poor prognosis and requires nuanced clinical decision-making. Surgery and radiation remain central to management. Adjuvant therapy offers substantial survival benefit in cSCC with PNI, with improved disease-free and overall survival compared with surgery alone, supporting its use in appropriately selected high-risk patients. Traditional systemic therapies, including cisplatin and cetuximab, remain foundational but have shown only moderate response rates and limited durability in advanced or neurotropic cSCC. In contrast, immunotherapy—now preferred for advanced or unresectable cases—has transformed management, with programmed cell death protein-1 (PD-1) inhibitors showing promising results (up to 69% response rate) and disease stabilization. Neoadjuvant immunotherapy may enable tumor downstaging, improve radiation planning, and reduce surgical morbidity. Imaging for squamous cell carcinoma (SCC) with PNI aids staging and surveillance, but symptoms remain key for detecting recurrence. Our multidisciplinary approach emphasizes personalized care. Larger trials are needed to define the optimal role and sequencing of immunotherapy in this high-risk patient population.

Malignant glioma is considered invariably recalcitrant, thus necessitating development of new therapeutic approaches. Spontaneously arising canine glioma exhibits important molecular and pathological similarities to malignant pediatric glioma, making it an invaluable model for testing novel therapies. We evaluated safety and activity of RNA lipid particle aggregates (LPAs) designed to provoke cancer immunogenicity in 10 dogs with histologically confirmed glioma. Vaccine manufacturing was feasible in all subjects and generally well tolerated. Median survival time was 123 and 155 days in dogs receiving three (Group A) or four (Group B) vaccines, respectively; this was increased from historical reporting of subjects receiving palliative care. Responding animals had a robust cytokine response following infusions. In animals receiving non-specific RNA-LPAs, there was localization of messenger RNA (mRNA) payloads to the brain tumor microenvironment and a rapid shift in immunologic gene signatures consistent with a viral response. These data demonstrate the ability to induce rapid viremic response in the tumor microenvironment following a single peripherally administered mRNA vaccine. Since RNA-LPAs are amenable to repeat boosts, these formulations may overcome challenges of tumor immunosuppression and therapeutic access and are currently under evaluation in first-in-human trials ( NCT04573140 , NCT06389591 ).

Abstract The 5-year survival rate for metastatic melanoma (MM) is 35% with rates increasing to ~50% with immune checkpoint blockade (ICB) treatment. Unfortunately, melanoma brain metastases (MBM) develop in nearly half of MM patients and often relapse rapidly following ICB treatment. MBM resistance to ICB can be attributed to tumor-associated macrophages (TAM). Transcriptional profiling of MM revealed that TAMs possess a lipidated phenotype suggesting that aberrant lipogenic processes confer ICB resistance. Stearoyl-CoA desaturase (SCD) is a lipogenic enzyme that is overexpressed in MM and may cause TAM lipidation. SCD serves as an attractive target for inhibition and combination with ICB for treating MBM. We hypothesize that SCD overexpression produces lipid-rich tumor cells that trigger a phenotypic switch towards immunosuppressive lipid-laden macrophages (LL-Mø). Clinical correlation analysis was conducted to assess SCD expression with ICB response. scRNA-seq data of MBM were analyzed to assess TAMs exhibiting lipidated phenotype. Phagocytosis and lipid transfer was assessed via macrophage and melanoma co-culture using time-lapse microscopy. In-silico modeling and LC-MS/MS was performed to assess blood brain barrier (BBB) penetrance of two small molecule inhibitors of SCD (SCDi): MTI-301 and MF-438. Clinical correlation analysis of MM patients revealed high SCD expression associated with decreased survival of patients treated with ICB. scRNA-seq analysis of MBM revealed upregulation of de novo lipogenesis and cholesterol uptake transcripts within TAM populations. Time-lapse co-culture studies reveal rapid lipid accumulation in macrophages. In-silico modeling predicted SCDi BBB penetration and was corroborated by LC-MS/MS. MBM are notoriously difficult to treat due to poor drug penetrance into CNS and unique microenvironment. We demonstrate that macrophages reprogram towards immunosuppressive LL-Mø, which can be exploited for anti-tumor targeting. The potential for SCDi to synergize with ICB in MBM may improve patient outcomes. MTI-301 is approved for first-in-human clinical trial starting end of 2025.