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Abstract Acquired resistance to BRAF/MEK-targeted therapy occurs in the majority of melanoma patients that harbor BRAF mutated tumors, leading to relapse or progression and the underlying mechanism is unclear in many cases. Using multiplex immunohistochemistry and spatial imaging analysis of paired tumor sections obtained from 11 melanoma patients prior to BRAF/MEK-targeted therapy and when the disease progressed on therapy, we observed a significant increase of tumor cellularity in the progressed tumors and the close association of SOX10+ melanoma cells with CD8+ T cells negatively correlated with patient’s progression-free survival (PFS). In the TCGA-melanoma dataset (n = 445), tumor cellularity exhibited additive prognostic value in the immune score signature to predict overall survival in patients with early-stage melanoma. Moreover, tumor cellularity prognoses OS independent of immune score in patients with late-stage melanoma.

Abstract Background While immune checkpoint blockade (ICB) is the current first-line treatment for metastatic melanoma, it is effective for ~ 52% of patients and has dangerous side effects. The objective here was to identify the feasibility and mechanism of RAS/RAF/PI3K pathway inhibition in melanoma to sensitize tumors to ICB therapy. Methods Rigosertib (RGS) is a non-ATP-competitive small molecule RAS mimetic. RGS monotherapy or in combination therapy with ICB were investigated using immunocompetent mouse models of BRAFwt and BRAFmut melanoma and analyzed in reference to patient data. Results RGS treatment (300 mg/kg) was well tolerated in mice and resulted in ~ 50% inhibition of tumor growth as monotherapy and ~ 70% inhibition in combination with αPD1 + αCTLA4. RGS-induced tumor growth inhibition depends on CD40 upregulation in melanoma cells followed by immunogenic cell death, leading to enriched dendritic cells and activated T cells in the tumor microenvironment. The RGS-initiated tumor suppression was partially reversed by either knockdown of CD40 expression in melanoma cells or depletion of CD8+ cytotoxic T cells. Treatment with either dabrafenib and trametinib or with RGS, increased CD40+SOX10+ melanoma cells in the tumors of melanoma patients and patient-derived xenografts. High CD40 expression level correlates with beneficial T-cell responses and better survival in a TCGA dataset from melanoma patients. Expression of CD40 by melanoma cells is associated with therapeutic response to RAF/MEK inhibition and ICB. Conclusions Our data support the therapeutic use of RGS + αPD1 + αCTLA4 in RAS/RAF/PI3K pathway-activated melanomas and point to the need for clinical trials of RGS + ICB for melanoma patients who do not respond to ICB alone. Trial registration NCT01205815 (Sept 17, 2010). Graphical abstract

Abstract Objective: To evaluate whether rates of healthcare-associated infections (HAIs) changed during the coronavirus disease 2019 (COVID-19) pandemic in malignant hematology and stem cell transplant patients. Design: A retrospective, cohort study. Patients: The study included malignant hematology and stem cell transplant patients admitted between March 1, 2019, through July 31, 2019, and March 1, 2020, through July 31, 2020. Methods: Rates of catheter-associated urinary tract infections (CAUTIs), central-line–associated bloodstream infections (CLABSIs), central-line–associated mucosal barrier injury infections (CLAMBIs), and Clostridioides difficile infections (CDIs) during the pandemic were compared to those in a control cohort. Secondary outcomes included the rate of non–COVID-19 respiratory viruses. Results: The rate of CAUTIs per 1,000 hospital days was 0.435 before the pandemic and 0.532 during the pandemic (incidence rate ratio [IRR], 1.224; 95% confidence interval [CI], 0.0314–47.72; P = .899). The rate of CLABSIs was 0.435 before the pandemic and 1.064 during the pandemic (IRR, 2.447; 95% CI, 0.186–72.18; P = .516). The rate of CLAMBIs was 2.61 before the pandemic and 1.064 during the pandemic (IRR 0.408, 95% CI 0.057–1.927; P = .284). The rate of CDIs was 2.61 before the pandemic and 1.579 during the pandemic (IRR, 0.612; 95% CI, 0.125–2.457; P = .512). Non–COVID-19 respiratory virus cases decreased significantly from 12 (30.8%) to 2 cases (8.3%) (P = 0.014). Conclusions: There was no significant difference in HAIs among inpatient malignant hematology and stem cell transplant patients during the COVID-19 pandemic compared to those of a control cohort. Rates of infection were low among both cohorts. Rates of community-acquired respiratory viruses decreased significantly during the pandemic among this population.

The addition of immune checkpoint inhibitors (ICIs) to the therapeutic armamentarium for solid malignancies has resulted in unprecedented improvements in patient outcomes in many cancers. The landscape of ICIs continues to evolve with novel approaches such as dual immune checkpoint blockade and combination therapies with other anticancer agents including cytotoxic chemotherapies and/or antiangiogenics. However, there is significant heterogeneity seen in antitumor responses, with certain patients deriving durable benefit, others experiencing initial benefit followed by acquired resistance necessitating change in therapy, and still others who are primarily refractory to ICIs. While generally better tolerated than traditional cytotoxic chemotherapy, ICIs are associated with unique toxicities, termed immune-related adverse events (irAEs), which can be severe or even lethal. As a disease of aging, older individuals make up a large proportion of patients diagnosed with cancer, yet this population is often underrepresented in clinical trials. Because ICIs indirectly target malignant cells through T cell activation, it has been hypothesized that age-related changes to the immune system may impact the efficacy and toxicity of these drugs. In this review, we discuss differences in the clinical efficacy and toxicity of ICIs in patients at the extremes of age.