Generation of novel oncolytic vaccinia virus with improved intravenous efficacy through protection against complement-mediated lysis and evasion of neutralization by vaccinia virus-specific antibodies.

BACKGROUND: Oncolytic virus immunotherapy has revolutionized cancer immunotherapy by efficiently inducing both oncolysis and systemic immune activation. Locoregional administration has been used for oncolytic virus therapy, but its applications to deep-seated cancers have been limited. Although systemic delivery of the oncolytic virus would maximize viral immunotherapy's potential, this remains a hurdle due to the rapid removal of the administered virus by the complement and innate immune system. Infected cells produce some vaccinia viruses as extracellular enveloped virions, which evade complement attack and achieve longer survival by expressing host complement regulatory proteins (CRPs) on the host-derived envelope. Here, we generated SJ-600 series oncolytic vaccinia viruses that can mimic complement-resistant extracellular enveloped virions by incorporating human CRP CD55 on the intracellular mature virion (IMV) membrane. METHODS: The N-terminus of the human CD55 protein was fused to the transmembrane domains of the six type I membrane proteins of the IMV; the resulting recombinant viruses were named SJ-600 series viruses. The SJ-600 series viruses also expressed human granulocyte-macrophage colony-stimulating factor (GM-CSF) to activate dendritic cells. The viral thymidine kinase (J2R) gene was replaced by genes encoding the CD55 fusion proteins and GM-CSF. RESULTS: SJ-600 series viruses expressing human CD55 on the IMV membrane showed resistance to serum virus neutralization. SJ-607 virus, which showed the highest CD55 expression and the highest resistance to serum complement-mediated lysis, exhibited superior anticancer activity in three human cancer xenograft models, compared with the control Pexa-Vec (JX-594) virus, after single-dose intravenous administration. The SJ-607 virus administration elicited neutralizing antibody formation in two immunocompetent mouse strains like the control JX-594 virus. Remarkably, we found that the SJ-607 virus evades neutralization by vaccinia virus-specific antibodies. CONCLUSION: Our new oncolytic vaccinia virus platform, which expresses human CD55 protein on its membrane, prolonged viral survival by protecting against complement-mediated lysis and by evading neutralization by vaccinia virus-specific antibodies; this may provide a continuous antitumor efficacy until a complete remission has been achieved. Such a platform may expand the target cancer profile to include deep-seated cancers and widespread metastatic cancers.

Glycolysis inhibition sensitizes non-small cell lung cancer with T790M mutation to irreversible EGFR inhibitors via translational suppression of Mcl-1 by AMPK activation.

The secondary EGF receptor (EGFR) T790M is the most common mechanism of resistance to reversible EGFR-tyrosine kinase inhibitors (TKI) in patients with non-small cell lung cancer (NSCLC) with activating EGFR mutations. Although afatinib (BIBW2992), a second-generation irreversible EGFR-TKI, was expected to overcome the acquired resistance, it showed limited efficacy in a recent phase III clinical study. In this study, we found that the inhibition of glycolysis using 2-deoxy-d-glucose (2DG) improves the efficacy of afatinib in H1975 and PC9-GR NSCLC cells with EGFR T790M. Treatment with the combination of 2DG and afatinib induced intracellular ATP depletion in both H1975 and PC9-GR cells, resulting in activation of AMP-activated protein kinase (AMPK). AMPK activation played a central role in the cytotoxicity of the combined treatment with 2DG and afatinib through the inhibition of mTOR. The alteration of the AMPK/mTOR signaling pathway by the inhibition of glucose metabolism induced specific downregulation of Mcl-1, a member of the antiapoptotic Bcl-2 family, through translational control. The enhancement of afatinib sensitivity by 2DG was confirmed in the in vivo PC9-GR xenograft model. In conclusion, this study examined whether the inhibition of glucose metabolism using 2DG enhances sensitivity to afatinib in NSCLC cells with EGFR T790M through the regulation of the AMPK/mTOR/Mcl-1 signaling pathway. These data suggest that the combined use of an inhibitor of glucose metabolism and afatinib is a potential therapeutic strategy for the treatment of patients with acquired resistance to reversible EGFR-TKIs due to secondary EGFR T790M.

The impact of cigarette smoking on the frequency of and qualitative differences in KRAS mutations in Korean patients with lung adenocarcinoma.

PURPOSE: This study was designed to determine the relationship of cigarette smoking to the frequency and qualitative differences among KRAS mutations in lung adenocarcinomas from Korean patients. MATERIALS AND METHODS: Detailed smoking histories were obtained from 200 consecutively enrolled patients with lung adenocarcinoma according to a standard protocol. EGFR (exons 18 to 21) and KRAS (codons 12/13) mutations were determined via direct-sequencing. RESULTS: The incidence of KRAS mutations was 8% (16 of 200) in patients with lung adenocarcinoma. KRAS mutations were found in 5.8% (7 of 120) of tumors from never-smokers, 15% (6 of 40) from former-smokers, and 7.5% (3 of 40) from current-smokers. The frequency of KRAS mutations did not differ significantly according to smoking history (p=0.435). Never-smokers were significantly more likely than former or current smokers to have a transition mutation (G→A or C→T) rather than a transversion mutation (G→T or G→C) that is known to be smoking-related (p=0.011). In a Cox regression model, the adjusted hazard ratios for the risk of progression with epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) were 0.24 (95% CI, 0.14-0.42; p<0.001) for the EGFR mutation and 1.27 (95% CI, 0.58-2.79; p=0.537) for the KRAS mutation. CONCLUSION: Cigarette smoking did not influence the frequency of KRAS mutations in lung adenocarcinomas in Korean patients, but influenced qualitative differences in the KRAS mutations.

A phase I trial of gefitinib and nimotuzumab in patients with advanced non-small cell lung cancer (NSCLC).

BACKGROUND: Nimotuzumab (TheraCIM®) is a humanized anti-epidermal growth factor receptor (EGFR) monoclonal antibody (mAb) with minimal skin toxicity. Combining a different class of anti-EGFR drug with gefitinib is a new strategy to overcome intrinsic and acquired resistance to gefitinib. The aim of this phase I trial was to determine recommended phase II dose (RPIID) and the safety of gefitinib and nimotuzumab combination treatment. METHODS: Patients with advanced/metastatic NSCLC were treated with escalating doses of weekly nimotuzumab (100mg or 200mg, IV) and fixed doses of daily gefitinib (250 mg/day, PO) until disease progression or unacceptable toxicity. We planned to enroll 10 additional patients at RPIID to ascertain the safety of treatment. EGFR mutations and KRAS mutations were analyzed from available tumor samples. RESULTS: A total of 16 patients were enrolled (3 in 100mg cohort, 13 in 200mg cohort). Six patients (37.5%) were female, and 5 (31.3%) were never smokers. Adenocarcinoma was the major histologic type (13 patients, 81.3%). Treatment was well-tolerated without dose-limiting toxicity (DLT). Four patients (25.0%) experienced grade 2 skin toxicity (1 in 100mg cohorts, 3 in 200mg cohort). Other common grade 1/2 toxicities were fatigue (37.5%) and diarrhea (25.0%). Among 16 evaluable patients, four patients (25.0%) achieved partial response and 7 patients (43.8%) had stable disease. Two of 4 responders had EGFR mutation (exon 19 deletion). CONCLUSIONS: Dual agent molecular targeting of EGFR with nimotuzumab and gefitinib in patients with advanced NSCLC is well-tolerated. The RPIID for nimotuzumab is 200mg weekly IV and for gefitinib 250 mg/day PO. Based upon this phase I trial, we are planning to conduct a randomized phase II trial comparing gefitinib and nimotuzumab with gefitinib alone in patients with advanced NSCLC.

The efficacy and toxicity of S-1 and cisplatin as first-line chemotherapy in recurrent or metastatic head and neck squamous cell carcinoma.

PURPOSE: To assess the clinical activity and toxicity of a combination chemotherapy regimen of S-1 and cisplatin in patients with recurrent and/or metastatic head and neck squamous cell carcinoma (HNSCC) in a retrospective study. METHODS: A total of 49 patients were treated in an outpatient setting with S-1 80 mg/m(2) on days 1-14 and with cisplatin 70 mg/m(2) on day 1 every 3 weeks for a maximum of six cycles as a first-line palliative chemotherapy. Patients who achieved complete response (CR), partial response (PR) or stable disease (SD) after six cycles received S-1 monotherapy as a maintenance therapy. RESULTS: The median patient age was 55 years (range 33-79), 89.8 % were male, and the Eastern Cooperative Oncology Group performance status distribution was 0/1/2 (20.4 %/73.5 %/6.1 %). Of the 43 evaluable patients, 2 (4.1 %) achieved CR and 20 (40.8 %) had a PR, for an overall response rate of 44.9 %. Thirteen patients (26.6 %) had SD. The median number of chemotherapy treatments was 4 (range 1-18). Nine patients received maintenance S-1 monotherapy after six cycles of combination chemotherapy. With a mean 10.5 months (range 1.3-25.1) of follow-up, the median progression-free and overall survival were 4.5 (95 % CI, 3.7-5.3 months) and 10.8 months (95 % CI, 5.9-15.6 months), respectively. The main grade 3-4 toxicities were neutropenia (37 %), anemia (16 %) and general weakness (8 %). Other toxicities, including nausea/vomiting, mucositis and neuropathy, were mostly grade 1-2 and easily manageable. CONCLUSIONS: The combination of S-1/cisplatin therapy had a favorable efficacy with manageable toxicity as a first-line chemotherapy regimen for advanced head and neck squamous cell carcinoma patients.

Activation of IL-6R/JAK1/STAT3 signaling induces de novo resistance to irreversible EGFR inhibitors in non-small cell lung cancer with T790M resistance mutation.

The secondary T790M mutation in epidermal growth factor receptor (EGFR) is the major mechanism of acquired resistance to EGFR tyrosine kinase inhibitors (TKI) in non-small cell lung cancer (NSCLC). Although irreversible EGFR TKIs, such as afatinib or dacomitinib, have been introduced to overcome the acquired resistance, they showed a limited efficacy in NSCLC with T790M. Herein, we identified the novel de novo resistance mechanism to irreversible EGFR TKIs in H1975 and PC9-GR cells, which are NSCLC cells with EGFR T790M. Afatinib activated interleukin-6 receptor (IL-6R)/JAK1/STAT3 signaling via autocrine IL-6 secretion in both cells. Inhibition of IL-6R/JAK1/STAT3 signaling pathway increased the sensitivity to afatinib. Cancer cells showed stronger STAT3 activation and enhanced resistance to afatinib in the presence of MRC5 lung fibroblasts. Blockade of IL-6R/JAK1 significantly increased the sensitivity to afatinib through inhibition of afatinib-induced STAT3 activation augmented by the interaction with fibroblasts, suggesting a critical role of paracrine IL-6R/JAK1/STAT3 loop between fibroblasts and cancer cells in the development of drug resistance. The enhancement of afatinib sensitivity by inhibition of IL-6R/JAK1/STAT3 signaling was confirmed in in vivo PC9-GR xenograft model. Similar to afatinib, de novo resistance to dacomitinib in H1975 and PC9-GR cells was also mediated by dacomitinib-induced JAK1/STAT3 activation. Taken together, these findings suggest that IL-6R/JAK1/STAT3 signaling can be a potential therapeutic target to enhance the efficacy of irreversible EGFR TKIs in patients with EGFR T790M.

Efficacy and toxicity of belotecan for relapsed or refractory small cell lung cancer patients.

INTRODUCTION: Belotecan (Camtobell, CKD602) is a new camptothecin-derivative antitumor agent that belongs to the topoisomerase inhibitors. The aim of this study was to evaluate the efficacy and safety of belotecan monotherapy as a second-line therapy in patients with relapsed or refractory small cell lung cancer (SCLC). METHODS: Between June 2008 and August 2011, a total of 50 patients with relapsed or refractory SCLC were treated with belotecan 0.5 mg/m for 5 consecutive days, every 3 weeks. We evaluated the overall response rate (ORR), the progression-free survival (PFS), and the overall survival (OS), and toxicity according to sensitivity to initial chemotherapy. RESULTS: The median age was 66 years (range, 43-84 years) and Eastern Cooperative Oncology Group performance was 0 or 1 in 34 patients (68%) and 2 in 16 patients (32%). Twenty patients (40%) had sensitive relapse and 30 patients (60%) had refractory disease. The ORR, PFS, and OS for sensitive patients were 20% (95% confidence interval [CI], 8-40), 2.8 months (95% CI, 0.53-5.06), and 6.5 months (95% CI, 1.58-11.42), respectively. In the refractory group, the ORR, PFS, and OS were 10% (95% CI, 1-21), 1.5 months (95% CI, 1.25-1.75), and 4.0 months (95% CI, 3.40-4.60), respectively. Most commonly reported grade-3 or -4 adverse events included neutropenia (54%), thrombocytopenia (38%), and anemia (32%). CONCLUSION: Belotecan showed modest activity with an acceptable safety profile as a second-line therapy in patients with relapsed or refractory SCLC.

Treatment outcome of patients with anaplastic thyroid cancer: a single center experience.

PURPOSE: Anaplastic thyroid cancer is known to have a poor prognosis due to its aggressive and rapid metastasis with median survival of less than 6 months. Multimodal treatment involving surgery and chemoradiotherapy has been used to improve the survival of patients. Here, we retrospectively review of treatment outcome of 13 consecutive patients who were treated at a single center. MATERIALS AND METHODS: We retrospectively reviewed medical records of 13 anaplastic thyroid cancer patients who received multidisciplinary treatment between 2006 and 2010. Kaplan-Meier survival curve was used to analyze progression-free survival and overall survival of patients. RESULTS: The median patient age at diagnosis was 69 years, and six patients had stage IVc diseases. Eight patients received primary surgery followed by radiotherapy or concurrent chemoradiotherapy (CCRT). Five patients received weekly doxorubicin-based definitive CCRT, but only one patient's condition remained stable, while the rest experienced rapid disease progression. The median progression-free survival was 2.8 months (95% CI, 1.2-4.4 months), and the median overall survival was 3.8 months (95% CI, 3.0-4.6 months). CONCLUSION: Patients with anaplastic thyroid cancer showed poor prognosis despite multimodality treatment. Therefore, identification of novel therapeutic targets is warranted to take an effective mode of treatment.

Distinct clinical features and outcomes in never-smokers with nonsmall cell lung cancer who harbor EGFR or KRAS mutations or ALK rearrangement.

BACKGROUND: The objectives of this study were to determine the proportions of major oncogenic alterations and to examine survival in genotype-specific subsets of never-smokers with nonsmall cell lung cancer (NSCLC). METHODS: The authors concurrently analyzed mutations in the epidermal growth factor receptor (EGFR) and v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) genes and investigated anaplastic lymphoma kinase (ALK) gene rearrangements in samples from 229 never-smokers with NSCLC. ALK rearrangements were identified by fluorescent in situ hybridization and were confirmed by immunohistochemistry. Mutations in EGFR (exons 18 to 21) and KRAS (codons 12 and 13) were determined by direct sequencing. RESULTS: Of 229 tumors, the frequency of EGFR mutations, ALK rearrangements, KRAS mutations, and no mutations (wild type [WT]) in any of the 3 genes (WT/WT/WT) was 48%, 8.3%, 3.5%, and 40.2%, respectively. All genetic alterations were mutually exclusive. The median progression-free survival after treatment with EGFR tyrosine kinase inhibitors (TKIs) was 12.8 months, 6.3 months, 2.1 months, and 1.6 months in patients with EGFR mutations, the WT/WT/WT genotype, KRAS mutations, and ALK rearrangements, respectively. In a Cox regression model, the adjusted hazard ratio for the risk of disease progression after treatment with EGFR TKIs was 0.59 (95% confidence interval [CI], 0.40-0.87; P = .008) for patients with EGFR mutations, 4.58 (95% CI, 2.07-10.15; P < .001) for patients with ALK rearrangements, and 4.23 (95% CI, 1.65-10.8; P = .003) for patients with KRAS mutations. Overall survival also differed significantly among genotypes. CONCLUSIONS: To the authors' knowledge, this was the largest comprehensive and concurrent analysis to date of 3 major oncogenic alterations in a cohort of East Asian never-smokers with NSCLC. Because survival outcomes differed among genotypes, and drugs that target specific alterations currently are available, genetic profiling to identify genotype-specific subsets can lead to successful treatment with appropriate kinase inhibitors.