Efficacy and safety of first-line avelumab in patients with advanced non-small cell lung cancer: results from a phase Ib cohort of the JAVELIN Solid Tumor study.

INTRODUCTION: Avelumab, an antiprogrammed death ligand-1 antibody, is approved as a monotherapy for treatment of metastatic Merkel cell carcinoma and advanced urothelial carcinoma, and in combination with axitinib for advanced renal cell carcinoma. We report the efficacy and safety of first-line avelumab in advanced non-small cell lung cancer (NSCLC). METHODS: In a phase I expansion cohort of the JAVELIN Solid Tumor trial, patients with treatment-naive, metastatic, or recurrent NSCLC received 10 mg/kg avelumab intravenously every 2 weeks. Endpoints included best overall response, duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety. RESULTS: Overall, 156 patients were enrolled and treated. Median duration of follow-up was 18.6 months (range, 15 to 23 months). The objective response rate was 19.9% (95% CI, 13.9 to 27.0), including complete response in 3 (1.9%) and partial response in 28 (17.9%). Median DOR was 12.0 months (95% CI, 6.9 to not estimable). Median PFS was 4.0 months (95% CI, 2.7 to 5.4) and the 6-month PFS rate was 38.5% (95% CI, 30.7 to 46.3). Median OS was 14.1 months (95% CI, 11.3 to 16.9) and the 12-month OS rate was 56.6% (95% CI, 48.2 to 64.1). Treatment-related adverse events (TRAEs) occurred in 107 patients (68.6%), including grade ≥3 TRAEs in 19 (12.2%). Immune-related adverse events and infusion-related reactions occurred in 31 (19.9%) and 40 patients (25.6%), respectively. No treatment-related deaths occurred. CONCLUSION: Avelumab showed antitumor activity with a tolerable safety profile as a first-line treatment in patients with advanced NSCLC. These data support further investigation of avelumab in the phase III JAVELIN Lung 100 study. TRIAL REGISTRATION DETAILS: ClinicalTrials.gov NCT01772004; registered January 21, 2013.

ARQ 197, a novel and selective inhibitor of the human c-Met receptor tyrosine kinase with antitumor activity.

The met proto-oncogene is functionally linked with tumorigenesis and metastatic progression. Validation of the receptor tyrosine kinase c-Met as a selective anticancer target has awaited the emergence of selective c-Met inhibitors. Herein, we report ARQ 197 as the first non-ATP-competitive small molecule that selectively targets the c-Met receptor tyrosine kinase. Exposure to ARQ 197 resulted in the inhibition of proliferation of c-Met-expressing cancer cell lines as well as the induction of caspase-dependent apoptosis in cell lines with constitutive c-Met activity. These cellular responses to ARQ 197 were phenocopied by RNAi-mediated c-Met depletion and further demonstrated by the growth inhibition of human tumors following oral administration of ARQ 197 in multiple mouse xenograft efficacy studies. Cumulatively, these data suggest that ARQ 197, currently in phase II clinical trials, is a promising agent for targeting cancers in which c-Met-driven signaling is important for their survival and proliferation.

Structural proteins of Hepatitis C virus induce interleukin 8 production and apoptosis in human endothelial cells.

Hepatitis C virus (HCV) infection is associated with inflammation of liver endothelium, which contributes to the pathogenesis of chronic hepatitis. The mechanism of this endothelitis is not understood, since the virus does not appear to infect endothelial cells productively. Here, an 'innocent bystander' mechanism related to HCV proteins was hypothesized and it was investigated whether the binding of HCV particles to human endothelium induced functional changes in the cells. Exposure of human umbilical vein endothelial cells (HUVECs) to HCV-like particles (HCV-LPs) resulted in increased interleukin 8 (IL8) production and induction of apoptosis. The IL8 supernatants collected after stimulation of HUVECs with HCV-LPs, BV-GUS (control baculovirus containing beta-glucuronidase) and appropriate controls were used to assay the transendothelial migration of neutrophils. This assay confirmed that HCV-LP-induced IL8 was functionally active. Using specific NF-kappaB inhibitors, it was also shown that HCV-LP-induced NF-kappaB activity mediated IL8 production in HUVECs. Apoptosis appeared to be mediated by the Fas/Fas-L pathway, as neutralizing antibodies for Fas and Fas-L significantly protected HUVECs against HCV-LP-induced apoptosis. Treatment of HUVECs with HCV-LPs also enhanced cellular Fas-L expression and augmented caspase-3 activation. This was confirmed by using a specific caspase-3 inhibitor, Z-Asp-Glu-Val-Asp-fluoromethyl ketone. As shown by blocking of specific chemokine receptors for IL8 on HUVECs, the induction of IL8 did not appear to contribute to HCV-LP-induced apoptosis. These results suggest that HCV proteins can trigger the release of inflammatory chemokines such as IL8 and cause endothelial apoptosis, thereby facilitating endothelitis.

Lipopolysaccharide-induced apoptosis of endothelial cells and its inhibition by vascular endothelial growth factor.

Endothelial injury is a major manifestation of septic shock induced by LPS. Recently, LPS was shown to induce apoptosis in different types of endothelial cells. In this study, we observed that pretreatment with vascular endothelial growth factor (VEGF), a known cell survival factor, blocked LPS-induced apoptosis in endothelial cells. We then further defined this LPS-induced apoptotic pathway and its inhibition by VEGF. We found that LPS treatment increased caspase-3 and caspase-1 activities and induced the cleavage of focal adhesion kinase. LPS also augmented expression of the pro-apoptotic protein Bax and the tumor suppressor gene p53. The pro-apoptotic Bax was found to translocate to the mitochondria from the cytosol following stimulation with LPS. Pretreatment of endothelial cells with VEGF inhibited the induction of both Bax and p53 as well as the activation of caspase-3. These data suggest that VEGF inhibits LPS-induced endothelial apoptosis by blocking pathways that lead to caspase activation.

Hepatitis C and human immunodeficiency virus envelope proteins cooperatively induce hepatocytic apoptosis via an innocent bystander mechanism.

We hypothesized that hepatocytes exposed to hepatitis C virus (HCV) and human immunodeficiency virus (HIV) might be injured via an "innocent bystander" mechanism due to cell-surface binding of viral proteins. To assess this, we studied the effects of HCV envelope protein E2 and T-tropic HIV envelope glycoprotein gp120 on hepatocytes and saw potent apoptosis. Either viral protein alone did not induce this effect. HCV E2 and M-tropic HIV gp120 also induced significant apoptosis. Blocking the CXCR4 receptor led to a reduction in apoptosis. HCV E2 and HIV gp120 acted collaboratively to trigger a specific set of downstream signaling events, including up-regulation of the Fas ligand and dephosphorylation of the anti-apoptotic molecule AKT. These results suggest that hepatic injury may occur in HCV/HIV coinfection through the induction of novel downstream signaling pathways and provide a rationale for therapeutic interventions that interfere with specific receptors and signaling molecules.