Microenvironmental Landscape of Human Melanoma Brain Metastases in Response to Immune Checkpoint Inhibition.

Melanoma-derived brain metastases (MBM) represent an unmet clinical need because central nervous system progression is frequently an end stage of the disease. Immune checkpoint inhibitors (ICI) provide a clinical opportunity against MBM; however, the MBM tumor microenvironment (TME) has not been fully elucidated in the context of ICI. To dissect unique elements of the MBM TME and correlates of MBM response to ICI, we collected 32 fresh MBM and performed single-cell RNA sequencing of the MBM TME and T-cell receptor clonotyping on T cells from MBM and matched blood and extracranial lesions.

Low expression of the PPARγ-regulated gene thioredoxin-interacting protein accompanies human melanoma progression and promotes experimental lung metastases.

The thioredoxin system plays key roles in regulating cancer cell malignancy. Here we identify the Thioredoxin-interacting protein (TXNIP) as a gene, which expression is regulated by PPARγ in melanoma cells. We show that high TXNIP expression levels associate with benign melanocytic lesions, with tumor regression in patients on MAP kinase targeted therapy, with decreased proliferation in patients' melanoma biopsies, and with cell cycle arrest in human melanoma cell lines.

Mixed Response to Immunotherapy in Patients with Metastatic Melanoma.

Background: Immunotherapy has improved overall survival in metastatic melanoma. Response to therapy can be difficult to evaluate as the traditionally used RECIST 1.1 criteria do not capture heterogeneous responses.

Adjuvant Therapy Failure Patterns in the Modern Era of Melanoma Management.

Background: The management of patients with resected stage 3 melanoma has changed significantly due to adoption of the Multicenter Selective Lymphadenectomy Trial (MSLT)-2 guidelines and to the survival benefit of adjuvant anti-PD-1 immunotherapy and BRAF/MEK-inhibitor (BRAF/MEKi) therapy. Data are scarce regarding recurrence patterns, adjuvant therapy responses, and therapy-associated adverse events (AEs) in the modern era.

Methods: This single-institution, retrospective study analyzed surgically resected stage 3 and oligometastatic stage 4 patients who received anti-PD-1, BRAF/MEKi, or surgery with active surveillance only.