Safety of Inactivated Influenza Vaccine in Cancer Patients Receiving Immune Checkpoint Inhibitors.

BACKGROUND: Cancer patients are at a higher risk for developing influenza (flu)- related complications. It is unclear if the flu vaccine exacerbates immune events in patients treated with immune checkpoint inhibitors (ICIs). METHODS: We conducted an institutional review board-IRB-approved retrospective review of advanced cancer patients on ICIs who received the flu vaccine during three 3 consecutive seasons: 2014-2015, 2015-2016, and 2016-2017. The primary outcome assessed was any "new onset" immune-related adverse event (IRAE). A subset analysis of vaccinated patients newly treated with anti-programmed cell death protein 1 (PD-1) agents (nivolumab or pembrolizumab) was conducted to assess overall IRAE rates for comparison with published clinical trials. RESULTS: During the three 3 seasons, 370 patients met criteria for ICI and vaccination within ~ twoapproximately 2 months (65 days). The most common underlying cancers were lung (46%) and melanoma (19%); 61% of patients received an anti-PD-1 agent only. In the entire cohort, 20% experienced an IRAE (any grade); incidence of grade 3 or 4 toxicity was 8%. No grade 5 events occurred. In the subset of 170 patients newly treated with anti-PD-1 agents, the overall IRAE rate was 18% and, grade 3/4 events occurred in 7.6%. Influenza was diagnosed in 2 patients. CONCLUSIONS: No increase in incidence or severity of IRAEs was detected in patients on ICIs who received the inactivated influenza vaccine within ~ approximately 2 months of ICI. For newly treated patients on anti-PDI-1 agents, IRAE rates were comparable to those from published clinical trials and did not vary with order of administration. Routine seasonal flu vaccination is encouraged in patients on ICIs.

Substituted oxines inhibit endothelial cell proliferation and angiogenesis.

Two substituted oxines, nitroxoline (5) and 5-chloroquinolin-8-yl phenylcarbamate (22), were identified as hits in a high-throughput screen aimed at finding new anti-angiogenic agents. In a previous study, we have elucidated the molecular mechanism of antiproliferative activity of nitroxoline in endothelial cells, which comprises of a dual inhibition of type 2 human methionine aminopeptidase (MetAP2) and sirtuin 1 (SIRT1). Structure-activity relationship study (SAR) of nitroxoline offered many surprises where minor modifications yielded oxine derivatives with increased potency against human umbilical vein endothelial cells (HUVEC), but with entirely different as yet unknown mechanisms. For example, 5-nitrosoquinolin-8-ol (33) inhibited HUVEC growth with sub-micromolar IC(50), but did not affect MetAP2 or MetAP1, and it only showed weak inhibition against SIRT1. Other sub-micromolar inhibitors were derivatives of 5-aminoquinolin-8-ol (34) and 8-sulfonamidoquinoline (32). A sulfamate derivative of nitroxoline (48) was found to be more potent than nitroxoline with the retention of activities against MetAP2 and SIRT1. The bioactivity of the second hit, micromolar HUVEC and MetAP2 inhibitor carbamate 22 was improved further with an SAR study culminating in carbamate 24 which is a nanomolar inhibitor of HUVEC and MetAP2.

The HBV drug entecavir - effects on HIV-1 replication and resistance.

Entecavir, a drug approved by the Food and Drug Administration for the treatment of chronic hepatitis B virus (HBV) infection, is not believed to inhibit replication of human immunodeficiency virus type 1 (HIV-1) at clinically relevant doses. We observed that entecavir led to a consistent 1-log(10) decrease in HIV-1 RNA in three persons with HIV-1 and HBV coinfection, and we obtained supportive in vitro evidence that entecavir is a potent partial inhibitor of HIV-1 replication. Detailed analysis showed that in one of these patients, entecavir monotherapy led to an accumulation of HIV-1 variants with the lamivudine-resistant mutation, M184V. In vitro experiments showed that M184V confers resistance to entecavir. Until more is known about HIV-1-resistance patterns and their selection by entecavir, caution is needed with the use of entecavir in persons with HIV-1 and HBV coinfection who are not receiving fully suppressive antiretroviral regimens.

Efficacy of pyrvinium pamoate against Cryptosporidium parvum infection in vitro and in a neonatal mouse model.

No effective approved drug therapy exists for Cryptosporidium infection of immunocompromised patients. Here we investigated the nonabsorbed anthelmintic drug pyrvinium pamoate for inhibition of the growth of the intestinal protozoan parasite Cryptosporidium parvum. The concentration of pyrvinium that effected 50% growth inhibition in human enterocytic HCT-8 cells by a quantitative alkaline phosphatase immunoassay was 354 nM. For comparison, in the same assay, 50% growth inhibition was obtained with 711 microM paromomycin or 27 microM chloroquine. We used a neonatal mouse model to measure the anti-Cryptosporidium activity of pyrvinium pamoate in vivo. Beginning 3 days after infection, pyrvinium at 5 or 12.5 mg/kg of body weight/day was administered to the treatment group mice for 4 or 6 consecutive days. Nine days after infection, the mice were sacrificed, and drug efficacy was determined by comparing the numbers of oocysts in the fecal smears of treated versus untreated mice. The intensities of trophozoite infection in the ileocecal intestinal regions were also compared using hematoxylin-and-eosin-stained histological slides. We observed a >90% reduction in infection intensity in pyrvinium-treated mice relative to that in untreated controls, along with a substantial reduction in tissue pathology. Based on these results, pyrvinium pamoate is a potential drug candidate for the treatment of cryptosporidiosis in both immunocompetent and immunocompromised individuals.

Catalysis of zinc transfer by D-penicillamine to secondary chelators.

The antiarthritis drug D-penicillamine (D-PEN) catalyzes zinc(II) transfer from carboxypeptidase A to chelators such as thionein and EDTA at a rate constant up to 400-fold faster than the uncatalyzed release. Once D-PEN releases zinc(II) from enzyme stronger chelators can tightly bind zinc(II) leading to complete and essentially irreversible inhibition. D-PEN is the first drug to inhibit a zinc protease by catalyzing metal removal, and the name "catalytic chelation" is proposed for this mechanism.

Identification of Existing Drugs That Effectively Target NTRK1 and ROS1 Rearrangements in Lung Cancer.

PURPOSE: Efforts to discover drugs that overcome resistance to targeted therapies in patients with rare oncogenic alterations, such as NTRK1 and ROS1 rearrangements, are complicated by the cost and protracted timeline of drug discovery. EXPERIMENTAL DESIGN: In an effort to identify inhibitors of NTRK1 and ROS1, which are aberrantly activated in some patients with non-small cell lung cancer (NSCLC), we created and screened a library of existing targeted drugs against Ba/F3 cells transformed with these oncogenes. RESULTS: This screen identified the FDA-approved drug cabozantinib as a potent inhibitor of CD74-ROS1-transformed Ba/F3, including the crizotinib-resistant mutants G2032R and L2026M (IC50 = 9, 26, and 11 nmol/L, respectively). Cabozantinib inhibited CD74-ROS1-transformed Ba/F3 cells more potently than brigatinib (wild-type/G2032R/L2026M IC50 = 30/170/200 nmol/L, respectively), entrectinib (IC50 = 6/2,200/3,500 nmol/L), and PF-06463922 (IC50 = 1/270/2 nmol/L). Cabozantinib inhibited ROS1 autophosphorylation and downstream ERK activation in transformed Ba/F3 cells and in patient-derived tumor cell lines. The IGF-1R inhibitor BMS-536924 potently inhibited CD74-NTRK1-transformed compared with parental Ba/F3 cells (IC50 = 19 nmol/L vs. > 470 nmol/L). A patient with metastatic ROS1-rearranged NSCLC with progression on crizotinib was treated with cabozantinib and experienced a partial response. CONCLUSIONS: While acquired resistance to targeted therapies is challenging, this study highlights that existing agents may be repurposed to overcome drug resistance and identifies cabozantinib as a promising treatment of ROS1-rearranged NSCLC after progression on crizotinib. Clin Cancer Res; 23(1); 204-13. ©2016 AACR.

Fumarranol, a rearranged fumagillin analogue that inhibits angiogenesis in vivo.

The fumagillin family of natural products inhibits angiogenesis through the irreversible inhibition of the type 2 methionine aminopeptidase (MetAP2). Herein is reported a novel fumagillin analogue named fumarranol. It is shown that, like fumagillin, fumarranol selectively inhibits MetAP2 and endothelial cell proliferation. It is also active in a mouse model of angiogenesis in vivo. Unlike TNP-470, fumarranol does not covalently bind to MetAP2. Fumarranol may serve as a lead for a new class of angiogenesis inhibitors.

Identification of type 1 inosine monophosphate dehydrogenase as an antiangiogenic drug target.

To rapidly discover clinically useful angiogenesis inhibitors, we created and screened a library of existing drugs for inhibition of endothelial cell proliferation. Mycophenolic acid (MPA), an immunosuppressive drug, was found to potently inhibit endothelial cell proliferation in vitro and block tumor-induced angiogenesis in vivo. Using RNA interference, we found that knockdown of one of the two known isoforms of inosine monophosphate dehydrogenase (IMPDH-1) is sufficient to cause endothelial cell cycle arrest.

Characterization of 2-hydroxy-1-naphthaldehyde isonicotinoyl hydrazone as a novel inhibitor of methionine aminopeptidases from Mycobacterium tuberculosis.

Mycobacterium tuberculosis (Mtb) and the Human Immunodeficiency Virus (HIV) pose a major public health threat. The 2015 World Health Organization (WHO) report estimates that one in three HIV deaths is due to Mtb, the causative agent of Tuberculosis (TB). The lethal synergy between these two pathogens leads to a decline in the immune function of infected individuals as well as a rise in morbidity and mortality rates. The deadly interaction between TB and HIV, along with the heightened emergence of drug resistance, drug-drug interactions, reduced drug efficacy and increased drug toxicity, has made the therapeutic management of co-infected individuals a major challenge. Hence, the development of new drug targets and/or new drug leads are imperative for the effective therapeutic management of co-infected patients. Here, we report the characterization of 2-hydroxy-1-naphthaldehyde isonicotinoyl hydrazone (311), a known inhibitor of HIV-1 replication and transcription as a new inhibitor of methionine aminopeptidases (MetAPs) from Mycobacterium tuberculosis: MtMetAP1a and MtMetAP1c. MetAP is a metalloprotease that removes the N-terminal methionine during protein synthesis. The essential role of MetAP in microbes makes it a promising chemotherapeutic target. We demonstrated that 311 is a potent and selective inhibitor of MtMetAP1a and MtMetAP1c. Furthermore, we found that 311 is active against replicating and aged non-growing Mtb at low micromolar concentrations. These results suggest that 311 is a promising lead for the development of novel class of therapeutic agents with dual inhibition of TB and HIV for the treatment of TB-HIV co-infection.

Anti-PD-1 Inhibitor-Related Pneumonitis in Non-Small Cell Lung Cancer.

The recent approval of two PD-1 inhibitors for the treatment of non-small cell lung cancer (NSCLC) has rapidly led to the widespread use of these agents in oncology practices. Pneumonitis has been recognized as a potentially life-threatening adverse event among NSCLC patients treated with PD-1 inhibitors; however, the detailed clinical and radiographic manifestations of this entity remain to be described. We report on two cases of anti-PD-1 pneumonitis in advanced NSCLC patients treated with nivolumab after its FDA approval. Both patients presented with ground-glass and reticular opacities and consolidations in a peripheral distribution on CT, demonstrating a radiographic pattern of cryptogenic organizing pneumonia. Consolidations were extensive and rapidly developed within 8 weeks of therapy in both cases. Both patients were treated with corticosteroids with subsequent improvement of respiratory symptoms and radiographic findings. One patient experienced recurrent pneumonitis after completing corticosteroid taper, or a "pneumonitis flare," in the absence of nivolumab retreatment, with subsequent improvement upon corticosteroid readministration. With the increasing use of immune checkpoint inhibitors in a growing number of tumor types, awareness of the radiographic and clinical manifestations of PD-1 inhibitor-related pneumonitis will be critical for the prompt diagnosis and management of this potentially serious adverse event.

Copper pathways in Plasmodium falciparum infected erythrocytes indicate an efflux role for the copper P-ATPase.

Copper, like iron, is a transition metal that can generate oxygen radicals by the Fenton reaction. The Plasmodium parasite invades an erythrocyte host cell containing 20 microM copper, of which 70% is contained in the Cu/Zn SOD (cuprozinc superoxide dismutase). In the present study, we follow the copper pathways in the Plasmodium-infected erythrocyte. Metal-determination analysis shows that the total copper content of Percoll-purified trophozoite-stage-infected erythrocytes is 66% that of uninfected erythrocytes. This decrease parallels the decrease seen in Cu/Zn SOD levels in parasite-infected erythrocytes. Neocuproine, an intracellular copper chelator, arrests parasites at the ring-to-trophozoite stage transition and also specifically decreases intraparasitic levels of Cu/Zn SOD and catalase. Up to 150 microM BCS (2,9-dimethyl-4,7-diphenyl-1,10-phenanthrolinedisulphonic acid), an extracellular copper chelator, has no effect on parasite growth. We characterized a single copy PfCuP-ATPase (Plasmodium falciparum copper P-ATPase) transporter, which, like the Crypto-sporidium parvum copper P-ATPase, has a single copper-binding domain: 'Met-Xaa-Cys-Xaa-Xaa-Cys'. Recombinant expression of the N-terminal metal-binding domain reveals that the protein specifically binds reduced copper. Transcription of the PfCuP-ATPase gene is the highest at late ring stage/early trophozoite, and is down-regulated in the presence of neocuproine. Immunofluorescence and electron microscopy indicate the transporter to be both in the parasite and on the erythrocyte membrane. Both the decrease in total copper and the location of the PfCuP-ATPase gene indicate a copper-efflux pathway from the infected erythrocyte.

Targeted therapy for Epstein-Barr virus-associated gastric carcinoma using low-dose gemcitabine-induced lytic activation.

The constant presence of the viral genome in Epstein-Barr virus (EBV)-associated gastric cancers (EBVaGCs) suggests the applicability of novel EBV-targeted therapies. The antiviral nucleoside drug, ganciclovir (GCV), is effective only in the context of the viral lytic cycle in the presence of EBV-encoded thymidine kinase (TK)/protein kinase (PK) expression. In this study, screening of the Johns Hopkins Drug Library identified gemcitabine as a candidate for combination treatment with GCV. Pharmacological induction of EBV-TK or PK in EBVaGC-originated tumor cells were used to study combination treatment with GCV in vitro and in vivo. Gemcitabine was found to be a lytic inducer via activation of the ataxia telangiectasia-mutated (ATM)/p53 genotoxic stress pathway in EBVaGC. Using an EBVaGC mouse model and a [125I] fialuridine (FIAU)-based lytic activation imaging system, we evaluated gemcitabine-induced lytic activation in an in vivo system and confirmed the efficacy of gemcitabine-GCV combination treatment. This viral enzyme-targeted anti-tumor strategy may provide a new therapeutic approach for EBVaGCs.

Inhibition of heme crystal growth by antimalarials and other compounds: implications for drug discovery.

During intraerythrocytic infection, Plasmodium falciparum parasites crystallize toxic heme released during hemoglobin catabolism. The proposed mechanism of quinoline inhibition of crystal growth is either by a surface binding or a substrate sequestration mechanism. The kinetics of heme crystal growth was examined in this work using a new high-throughput crystal growth determination assay based on the differential solubility of free vs. crystalline FP in basic solutions. Chloroquine (IC(50)=4.3 microM) and quinidine (IC(50)=1.5 microM) showed a previously not recognized reversible inhibition of FP crystal growth. This inhibition decreased by increasing amounts of heme crystal seed, but not by greater amounts of FP substrate. Crystal growth decreases as pH rises from 4.0 to 6.0, except for a partial local maxima reversal from pH 5.0 to 5.5 that coincides with increased FP solubility. The new crystal growth determination assay enabled a partial screen of existing clinical drugs. Nitrogen heterocycle cytochrome P450 inhibitors also reversibly blocked FP crystal growth, including the azole antifungal drugs clotrimazole (IC(50)=12.9 microM), econazole (IC(50)=19.7 microM), ketoconazole (IC(50)=6.5 microM), and miconazole (IC(50)=21.4 microM). Fluconazole did not inhibit. Both subcellular fractionation of parasites treated with subinhibitory concentrations of ketoconazole and in vitro hemozoin growth assays demonstrated copurification of hemozoin and ketoconazole. The chemical diversity of existing CYP inhibitor libraries that bind FP presents new opportunities for the discovery of antimalarial drugs that block FP crystal growth by a surface binding mechanism and possibly interfere with other FP-sensitive Plasmodium pathways.

Chemotherapy for locally advanced and metastatic pulmonary carcinoid tumors.

OBJECTIVES: The optimal management of locally advanced and metastatic pulmonary carcinoid tumors remains to be determined. MATERIALS AND METHODS: A retrospective review was conducted on patients with typical and atypical pulmonary carcinoid tumors treated at our institutions between 1990 and 2012. RESULTS: 300 patients were identified with pulmonary carcinoid, (80 patients with atypical carcinoid), of whom 29 presented with metastatic disease (16 atypical). Of evaluable patients, 26 (41%) with stages I-III atypical carcinoid tumors recurred at a median time of 3.7 years (range, 0.4-32), compared to 3 (1%) patients with typical carcinoid (range, 8-12.3). 39 patients were treated with chemotherapy, including 30 patients with metastatic disease (27 atypical), and 7 patients were treated with adjuvant platinum-etoposide chemoradiation (6 atypical, 1 typical, 6 stage IIIA, 1 stage IIB). At a median follow-up of 2 years there were 2 recurrences in the 7 patients receiving adjuvant treatment. Median survival after diagnosis of metastatic disease for patients with atypical pulmonary carcinoid was 3.3 years with a 5-year survival of 24%. Treatment regimens showing efficacy in pulmonary carcinoid include 15 patients treated with octreotide-based therapies (10% response rate (RR), 70% disease control rate (DCR), 15 month median progression-free survival (PFS)), 13 patients treated with etoposide+platinum (23% RR, 69% DCR, 7 month median PFS), and 14 patients treated with temozolomide-based therapies (14% RR, 57% DCR, 10 month median PFS). 8 of 10 patients with octreotide-avid disease treated with an octreotide-based regimen experienced disease control (1 partial response, 7 stable disease) for a median of 18 months (range 6-72 months). CONCLUSIONS: These results support our previous finding that a subset of pulmonary carcinoid tumors are responsive to chemotherapy.

The quest to overcome resistance to EGFR-targeted therapies in cancer.

All patients with metastatic lung, colorectal, pancreatic or head and neck cancers who initially benefit from epidermal growth factor receptor (EGFR)-targeted therapies eventually develop resistance. An increasing understanding of the number and complexity of resistance mechanisms highlights the Herculean challenge of killing tumors that are resistant to EGFR inhibitors. Our growing knowledge of resistance pathways provides an opportunity to develop new mechanism-based inhibitors and combination therapies to prevent or overcome therapeutic resistance in tumors. We present a comprehensive review of resistance pathways to EGFR-targeted therapies in lung, colorectal and head and neck cancers and discuss therapeutic strategies that are designed to circumvent resistance.