EGFR High Copy Number Together With High EGFR Protein Expression Predicts Improved Outcome for Cetuximab-based Therapy in Squamous Cell Lung Cancer: Analysis From SWOG S0819, a Phase III Trial of Chemotherapy With or Without Cetuximab in Advanced NSCLC.

BACKGROUND: The phase III S0819 trial investigated addition of cetuximab to first-line chemotherapy (CT) in NSCLC. Subgroup analyses suggested an OS benefit among patients with EGFR copy number gain in squamous cell carcinomas (SCC), (HR = 0.58 [0.39-0.86], P = .0071). A more detailed model based on EGFR FISH, EGFR IHC and KRAS mutation status was evaluated to yield a more precise predictive paradigm of cetuximab-based therapy in advanced NSCLC. METHODS: FISH was performed using the Colorado Scoring Criteria; H-Score was used to quantify EGFR IHC expression (cut-off ≥ 200). A Cox model was used to assess treatment effects for OS and PFS within biomarker and clinical subgroups. KRAS mutation was analyzed using Therascreen. The false discovery rate controlled for multiple comparisons. S0819 ClinicalTrials.gov Identifier: NCT00946712. RESULTS: Of 1,313 eligible patients, assay results were obtained for FISH on 976 patients (41% positive), for IHC on 945 patients (31% positive), and KRAS mutation status on 627 patients (26% positive). In SCC patients, OS was significantly improved with addition of cetuximab when both EGFR FISH and EGFR IHC were positive (N = 58), (OS HR: 0.32 [95% CI 0.18-0.59]; P = .0002, q = 0.08), median 12.6 versus 4.6 months. The results were independent of KRAS mutation status. In Non-SCC, no predictive value of EGFR IHC, EGFR FISH status and/or KRAS status was seen. CONCLUSIONS: In NSCLC SCC, a combination index of EGFR FISH plus EGFR IHC results was associated with improved OS when cetuximab was added to CT, representing a potential predictive molecular paradigm for patients suitable for EGFR-antibody therapy.

Testing Cancer Immunotherapy in a Human Immune System Mouse Model: Correlating Treatment Responses to Human Chimerism, Therapeutic Variables and Immune Cell Phenotypes.

Over the past decade, immunotherapies have revolutionized the treatment of cancer. Although the success of immunotherapy is remarkable, it is still limited to a subset of patients. More than 1500 clinical trials are currently ongoing with a goal of improving the efficacy of immunotherapy through co-administration of other agents. Preclinical, small-animal models are strongly desired to increase the pace of scientific discovery, while reducing the cost of combination drug testing in humans. Human immune system (HIS) mice are highly immune-deficient mouse recipients rtpeconstituted with human hematopoietic stem cells. These HIS-mice are capable of growing human tumor cell lines and patient-derived tumor xenografts. This model allows rapid testing of multiple, immune-related therapeutics for tumors originating from unique clinical samples. Using a cord blood-derived HIS-BALB/c-Rag2nullIl2rγnullSIRPαNOD (BRGS) mouse model, we summarize our experiments testing immune checkpoint blockade combinations in these mice bearing a variety of human tumors, including breast, colorectal, pancreatic, lung, adrenocortical, melanoma and hematological malignancies. We present in-depth characterization of the kinetics and subsets of the HIS in lymph and non-lymph organs and relate these to protocol development and immune-related treatment responses. Furthermore, we compare the phenotype of the HIS in lymph tissues and tumors. We show that the immunotype and amount of tumor infiltrating leukocytes are widely-variable and that this phenotype is tumor-dependent in the HIS-BRGS model. We further present flow cytometric analyses of immune cell subsets, activation state, cytokine production and inhibitory receptor expression in peripheral lymph organs and tumors. We show that responding tumors bear human infiltrating T cells with a more inflammatory signature compared to non-responding tumors, similar to reports of "responding" patients in human immunotherapy clinical trials. Collectively these data support the use of HIS mice as a preclinical model to test combination immunotherapies for human cancers, if careful attention is taken to both protocol details and data analysis.

Macrophages mediate lung inflammation in a mouse model of ischemic acute kidney injury.

Serum IL-6 is increased in acute kidney injury (AKI) and inhibition of IL-6 reduces AKI-mediated lung inflammation. We hypothesized that circulating monocytes produce IL-6 and that alveolar macrophages mediate lung inflammation after AKI via chemokine (CXCL1) production. To investigate systemic and alveolar macrophages in lung injury after AKI, sham operation or 22 min of renal pedicle clamping (AKI) was performed in three experimental settings: 1) systemic macrophage depletion via diphtheria toxin (DT) injection to CD11b-DTR transgenic mice, 2) DT injection to wild-type mice, and 3) alveolar macrophage depletion via intratracheal (IT) liposome-encapsulated clodronate (LEC) administration to wild-type mice. In mice with AKI and systemic macrophage depletion (CD11b-DTR transgenic administered DT) vs. vehicle-treated AKI, blood monocytes and lung interstitial macrophages were reduced, renal function was similar, serum IL-6 was increased, lung inflammation was improved, lung CXCL1 was reduced, and lung capillary leak was increased. In wild-type mice with AKI administered DT vs. vehicle, serum IL-6 was increased. In mice with AKI and alveolar macrophage depletion (IT-LEC) vs. AKI with normal alveolar macrophage content, blood monocytes and lung interstitial macrophages were similar, alveolar macrophages were reduced, renal function was similar, lung inflammation was improved, lung CXCL1 was reduced, and lung capillary leak was increased. In conclusion, administration of DT in AKI is proinflammatory, limiting the use of the DTR-transgenic model to study systemic effects of AKI. Mice with AKI and either systemic mononuclear phagocyte depletion or alveolar macrophage depletion had reduced lung inflammation and lung CXCL1, but increased lung capillary leak; thus, mononuclear phagocytes mediate lung inflammation, but they protect against lung capillary leak after ischemic AKI. Since macrophage activation and chemokine production are key events in the development of acute lung injury (ALI), these data provide further evidence that AKI may cause ALI.