Atezolizumab Plus Carboplatin and Etoposide in Patients with Untreated Extensive-Stage Small-Cell Lung Cancer: Interim Results of the MAURIS Phase IIIb Trial.

BACKGROUND: MAURIS is an Italian multicenter, open-label, phase IIIb ongoing trial, aiming at evaluating the safety and effectiveness of atezolizumab + carboplatin/etoposide in patients with newly diagnosed, extensive-stage small-cell lung cancer (ES-SCLC). The primary objective is the safety evaluation. MATERIALS AND METHODS: Patients received atezolizumab + carboplatin/etoposide Q3W for 4-6 cycles in the induction phase, followed by atezolizumab maintenance Q3W. We presented the interim analysis on safety (referring to the induction phase) and clinical effectiveness, in all patients (N = 154) and in subgroups that received ≤3 (N = 23), 4 (N = 43), and 5-6 cycles (N = 89) of induction. RESULTS: At a median follow-up of 10.5 months, 139 patients (90.3%) discontinued treatment. Serious adverse events occurred in 29.9% of patients overall, and the rate was lower in patients with 5-6 cycles (19.1%) than in those with 4 (34.9%) or ≤3 (63.6%) cycles. Immune-mediated adverse events were reported in 14.9%, 15.7%, 11.6%, and 18.2% of patients, overall and by subgroup, respectively. The median overall survival and progression-free survival were 10.7 and 5.5 months, respectively. Overall, 111 patients (71.6%) had a tumor response. CONCLUSIONS: Interim results provide further evidences about safety and efficacy profile of atezolizumab + carboplatin/etoposide treatment in a ES-SCLC patient population closer to that observed in clinical practice. CLINICAL TRIAL REGISTRATION: Eudract No. 2019-001146-17, NCT04028050.

Pulmonary leiomyosarcoma arising in pulmonary hamartoma: an exceptional occurrence in a rare tumor.

A solitary peripheral lung nodule was found in the left lung of a 52-year-old man. It was located in the lower lobe and measured 18.5 cm of major axis on chest computed tomography. A tru-cut core biopsy was obtained and a proliferation of bland, monomorphic, spindle cells in interlacing fascicles was observed. Accordingly, a surgical resection of the neoplasm was subsequently carried out. Macroscopically, the tumor appeared as a well-circumscribed nodule with a firm and whitish cut surface. Histologically, the neoplasm was predominantly composed of bland and monomorphic spindle cells, with a predominantly fascicular growth pattern, in which many tubular and cleft-like spaces of entrapped normal respiratory epithelium were involved. Myxoid change, stromal hyalinization and scattered bizarre mononucleated and multinucleated cells were also observed. Based on clinico-morphological, immunophenotypical and molecular features, we made a diagnosis of malignant transformation of pulmonary adenoleiomyomatous hamartoma into pulmonary leiomyosarcoma. As far as we know, this is the first described case of this exceptionally rare occurrence in an already rare neoplasm.

ITGB1 and DDR activation as novel mediators in acquired resistance to osimertinib and MEK inhibitors in EGFR-mutant NSCLC.

Osimertinib is a third-generation tyrosine kinase inhibitor clinically approved for first-line treatment of EGFR-mutant non-small cell lung cancer (NSCLC) patients. Although an impressive drug response is initially observed, in most of tumors, resistance occurs after different time and an alternative therapeutic strategy to induce regression disease is currently lacking. The hyperactivation of MEK/MAPKs, is one the most common event identified in osimertinib-resistant (OR) NSCLC cells. However, in response to selective drug pressure, the occurrence of multiple mechanisms of resistance may contribute to treatment failure. In particular, the epithelial-to-mesenchymal transition (EMT) and the impaired DNA damage repair (DDR) pathways are recognized as additional cause of resistance in NSCLC thus promoting tumor progression. Here we showed that concurrent upregulation of ITGB1 and DDR family proteins may be associated with an increase of EMT pathways and linked to both osimertinib and MEK inhibitor resistance to cell death. Furthermore, this study demonstrated the existence of an interplay between ITGB1 and DDR and highlighted, for the first time, that combined treatment of MEK inhibitor with DDRi may be relevant to downregulate ITGB1 levels and increase cell death in OR NSCLC cells.

PBMCs as Tool for Identification of Novel Immunotherapy Biomarkers in Lung Cancer.

BACKGROUND: Lung cancer (LC), including both non-small (NSCLC) and small (SCLC) subtypes, is currently treated with a combination of chemo- and immunotherapy. However, predictive biomarkers to identify high-risk patients are needed. Here, we explore the role of peripheral blood mononuclear cells (PBMCs) as a tool for novel biomarkers searching. METHODS: We analyzed the expression of the cGAS-STING pathway, a key DNA sensor that activates during chemotherapy, in PBMCs from LC patients divided into best responders (BR), responders (R) and non-responders (NR). The PBMCs were whole exome sequenced (WES). RESULTS: PBMCs from BR and R patients of LC cohorts showed the highest levels of STING (p < 0.0001) and CXCL10 (p < 0.0001). From WES, each subject had at least 1 germline/somatic alteration in a DDR gene and the presence of more DDR gene mutations correlated with clinical responses, suggesting novel biomarker implications. Thus, we tested the effect of the pharmacological DDR inhibitor (DDRi) in PBMCs and in three-dimensional spheroid co-culture of PBMCs and LC cell lines; we found that DDRi strongly increased cGAS-STING expression and tumor infiltration ability of immune cells in NR and R patients. Furthermore, we performed FACS analysis of PBMCs derived from LC patients from the BR, R and NR cohorts and we found that cytotoxic T cell subpopulations displayed the highest STING expression. CONCLUSIONS: cGAS-STING signaling activation in PBMCs may be a novel potential predictive biomarker for the response to immunotherapy and high levels are correlated with a better response to treatment along with an overall increased antitumor immune injury.