A Phase 1/2 Study to Evaluate the Safety and Activity of Nivolumab in Combination With Vorolanib, a Vascular Endothelial Growth Factor Tyrosine Kinase Inhibitor, in Patients With Refractory Thoracic Tumors.

Introduction: Targeting the tumor microenvironment may enhance response to immunotherapy (immune checkpoint inhibitors) and improve outcomes for patients. This study tested the safety and efficacy of vorolanib, a novel tyrosine kinase inhibitor of vascular endothelial growth factor, platelet-derived growth factor, and c-KIT, in combination with programmed cell death protein 1 blockade using nivolumab for refractory thoracic malignancies. Methods: This single-arm multicenter study enrolled patients with extensive-stage SCLC, thymic carcinoma, and NSCLC, either naive or had progressed on previous chemotherapy or immune checkpoint inhibitors (either primary or acquired resistance). The primary objective of phase 1 was to determine the maximum tolerated dose, and the primary end point for each dose-expansion cohort was the objective response rate. Results: A total of 88 patients were enrolled in phase 1 (n = 11) and dose expansion (n = 77) cohorts. Transaminitis was dose-limiting and expansion proceeded with oral vorolanib 200 mg daily combined with intravenous nivolumab 240 mg every 2 weeks. The objective response rate per cohort were as follows: NSCLC naive 33% (five of 15, 95% confidence interval [CI]: 13%-60%), NSCLC primary refractory 5.9% (one of 17, 95% CI: 0%-17.6%), NSCLC acquired resistance 11.1% (two of 18, 95% CI: 0%-27.8%); SCLC 0% (zero of 18), and thymic carcinoma 11% (one of nine, 95% CI: 0%-33%). Disease control rate ranged from 11.1% in SCLC (two of 18, 0%-27.8%) to 66.7 % in thymic carcinoma (six of nine, 95% CI: 33.3%-100%). The most common adverse events were fatigue (32%), aspartate transaminase (27%) and alanine transaminase elevation (25%), and diarrhea (19%). Transaminitis was more common in patients with thymic carcinoma than other tumors. Conclusions: Vorolanib plus nivolumab had a manageable safety profile and may have clinical benefits in various thoracic malignancies. The disease control rate in thymic malignancies warrants further assessment.

Identification of calcium-modulating cyclophilin ligand as a human host restriction to HIV-1 release overcome by Vpu.

The HIV-1 Vpu protein is required for efficient viral release from human cells. For HIV-2, the envelope (Env) protein replaces the role of Vpu. Both Vpu and HIV-2 Env enhance virus release by counteracting an innate host-cell block within human cells that is absent in African green monkey (AGM) cells. Here we identify calcium-modulating cyclophilin ligand (CAML) as a Vpu-interacting host factor that restricts HIV-1 release. Expression of human CAML (encoded by CAMLG) in AGM cells conferred a strong restriction of virus release that was reversed by Vpu and HIV-2 Env, suggesting that CAML is the mechanistic link between these two viral regulators. Depletion of CAML in human cells eliminated the need for Vpu in enhancing HIV-1 and murine leukemia virus release. These results point to CAML as a Vpu-sensitive host restriction factor that inhibits HIV release from human cells. The ability of CAML to inhibit virus release should illuminate new therapeutic strategies against HIV.

Murine norovirus 1 infection is associated with histopathological changes in immunocompetent hosts, but clinical disease is prevented by STAT1-dependent interferon responses.

Human noroviruses are the major cause of nonbacterial epidemic gastroenteritis worldwide. However, little is known regarding their pathogenesis or the immune responses that control them because until recently there has been no small animal model or cell culture system of norovirus infection. We recently reported the discovery of the first murine norovirus, murine norovirus 1 (MNV-1), and its cultivation in macrophages and dendritic cells in vitro. We further defined interferon receptors and the STAT-1 molecule as critical in both resistance to MNV-1-induced disease in vivo and control of virus growth in vitro. To date, neither histopathological changes upon infection nor viral replication in wild-type mice has been shown. Here we extend our studies to demonstrate that MNV-1 replicates and rapidly disseminates to various tissues in immunocompetent mice and that infection is restricted by STAT1-dependent interferon responses at the levels of viral replication and virus dissemination. Infection of wild-type mice is associated with histopathological alterations in the intestine (mild inflammation) and the spleen (red pulp hypertrophy and white pulp activation); viral dissemination to the spleen, liver, lung, and lymph nodes; and low-level persistent infection in the spleen. STAT-1 inhibits viral replication in the intestine, prevents virus-induced apoptosis of intestinal cells and splenocytes, and limits viral dissemination to peripheral tissues. These findings demonstrate that murine norovirus infection of wild-type mice is associated with initial enteric seeding and subsequent extraintestinal spread, and they provide mechanistic evidence of the role of STAT-1 in controlling clinical norovirus-induced disease.