Phase II study of cetuximab plus S-1/cisplatin therapy in Japanese patients with advanced gastric cancer.

OBJECTIVE: We evaluated the efficacy and safety of first-line S-1 plus cisplatin in combination with cetuximab for Japanese patients with advanced gastric cancer, including gastroesophageal junction adenocarcinoma. METHODS: This open-label, single arm, multicenter, phase 2 trial was conducted to assess first-line cetuximab plus S-1 plus cisplatin for advanced gastric cancer. A total of 40 patients from 10 centers were enrolled. Cetuximab was administered weekly, with the initial infusion at 400 mg/m2 and then 250 mg/m2 each subsequent week. S-1 plus cisplatin chemotherapy was concomitantly conducted in a 5-week cycle: S-1 (40-60 mg, adjusted for body surface area) was given twice daily for 3 consecutive weeks, followed by a 2-week rest period, and cisplatin (60 mg/m2) was given on day 8 of each cycle for a maximum of 8 cycles. Treatment continued until the occurrence of radiographically confirmed progressive disease, unacceptable toxicity or withdrawal of consent. The primary endpoint was the best overall response. Secondary endpoints included progression-free survival and safety. RESULTS: A total of 40 patients were evaluable. One patient (2.5%) had a complete response; 15 patients (37.5%) had a partial response. The observed overall response rate according to the independent review committee was 40.0% (95% confidence interval, 24.9-56.7; P = 0.7043 [one-sided null hypothesis: overall response rate ≤ 43%]); median PFS was 5.6 months (95% confidence intervals, 4.2-8.3). No adverse events leading to death were reported during the study, and no specific safety concerns were observed. CONCLUSIONS: Overall, the addition of cetuximab to S-1 plus cisplatin was well tolerated in patients with advanced gastric cancer but provided no additional clinical benefit in this study. ClinicalTrials.gov identifier: NCT01388790.

Phase I Study of the Bifunctional Fusion Protein Bintrafusp Alfa in Asian Patients with Advanced Solid Tumors, Including a Hepatocellular Carcinoma Safety-Assessment Cohort.

LESSONS LEARNED: Bintrafusp alfa had a manageable safety profile and demonstrated preliminary clinical activity in heavily pretreated patients with solid tumors (including hepatocellular carcinoma) with no or limited treatment options. Findings from this study suggest bintrafusp alfa may be a novel therapeutic approach for patients with advanced solid tumors. Additional trials are needed to further explore safety and efficacy of bintrafusp alfa in specific tumor types. BACKGROUND: Bintrafusp alfa is a first-in-class bifunctional fusion protein composed of the extracellular domain of transforming growth factor-ß (TGF-ß) RII receptor (a TGF-ß "trap") fused to a human immunoglobulin (Ig) G1 antibody blocking programmed death-ligand 1 (PD-L1). Bintrafusp alfa is designed to neutralize TGF-ß signaling by "trapping" and sequestering all TGF-ß isoforms, and this trap function is physically linked to PD-L1 blockade in the tumor microenvironment. METHODS: NCT02699515 was a phase I, open-label, dose-escalation study of bintrafusp alfa (3, 10, and 20 mg/kg every 2 weeks) in Asian patients with advanced solid tumors, including a hepatocellular carcinoma (HCC) safety-assessment cohort. The primary objective was safety and tolerability; the secondary objective is best overall response. RESULTS: As of August 24, 2018, 23 patients (including 9 in the HCC cohort) received bintrafusp alfa. Eight patients experienced treatment-related adverse events (TRAEs). Three patients had grade 3 TRAEs (13.0%; hypoacusis, hyponatremia, hypopituitarism, increased blood creatine phosphokinase, and intracranial tumor hemorrhage); one had grade 4 hyponatremia (4.3%). No treatment-related deaths occurred. In the dose-escalation cohort, two patients had a confirmed partial response, and 3 had stable disease (SD), for an overall response rate of 14.3% and a disease control rate (DCR) of 35.7%. In the HCC cohort, one patient had SD (DCR, 11.1%). A dose-proportional pharmacokinetics profile was observed at doses of >3 mg/kg. CONCLUSION: Bintrafusp alfa had a manageable safety profile and preliminary efficacy in heavily pretreated patients with advanced solid tumors, including HCC.

Phase I trial of the MET inhibitor tepotinib in Japanese patients with solid tumors.

OBJECTIVES: Tepotinib (MSC2156119J) is an oral, potent and highly selective small molecule mesenchymal-epithelial transition factor (MET) inhibitor for which the recommended Phase II dose of 500 mg once daily has been defined, based on the first-in-man trial conducted in the USA and Europe. We carried out a multicenter Phase I trial with a classic `3 + 3' design to determine the recommended Phase II dose in Japanese patients with solid tumors (NCT01832506). METHODS: Patients aged ≥20 years with advanced solid tumors (refractory to standard therapy or for whom no effective standard therapy was available) received tepotinib at 215, 300 or 500 mg once daily in a 21-day cycle. Occurrence of dose-limiting toxicities during cycle 1 was used to determine the maximum tolerated dose. Efficacy, safety and pharmacokinetics were also evaluated to support the dose assessment. RESULTS: Twelve patients were treated. Tepotinib was generally well tolerated with no observed dose-limiting toxicities; treatment-related adverse events were mainly grades 1-2. The tolerability profile of tepotinib was similar to that observed in non-Japanese populations. Pharmacokinetics in Japanese and Western patients was comparable. One patient with gastric cancer and one patient with urachal cancer had stable disease of ≥12 weeks in duration. The observed safety profile and pharmacokinetics are comparable with those in patients from the USA and Europe, and the recommended Phase II dose of tepotinib in Japanese patients was confirmed as 500 mg once daily. CONCLUSIONS: These results, including initial signals of antitumor activity, support further development of tepotinib in Japanese patients with cancer.

Phase 1 trial of avelumab (anti-PD-L1) in Japanese patients with advanced solid tumors, including dose expansion in patients with gastric or gastroesophageal junction cancer: the JAVELIN Solid Tumor JPN trial.

BACKGROUND: Avelumab is a human anti-PD-L1 IgG1 monoclonal antibody that has shown antitumor activity in several advanced cancers. We report results from JAVELIN Solid Tumor JPN, a phase 1 trial of avelumab in Japanese patients with advanced solid tumors with expansion in patients with advanced gastric cancer/gastroesophageal junction cancer. METHODS: In the dose-escalation part, eligible patients had various previously treated metastatic or advanced solid tumors. In the dose-expansion part, patients had stage IV gastric cancer/gastroesophageal junction adenocarcinoma and disease progression after prior therapy that included a platinum and fluoropyrimidine agent. Patients received avelumab every 2 weeks intravenously at 3, 10, or 20 mg/kg during dose escalation and 10 mg/kg during dose expansion. RESULTS: Among 17 patients who received avelumab in the dose-escalation part, no dose-limiting toxicities occurred, and the maximum tolerated dose was not reached. 40 patients were enrolled in the dose-expansion part, of whom 21 (52.5%) had received ≥ 3 prior lines of therapy for advanced disease. In these patients, the objective response rate was 10.0% (95% CI, 2.8-23.7%) and median overall survival was 9.1 months (95% CI, 7.2-11.2 months). Three of 40 patients (7.5%) had a grade 3 treatment-related adverse event (alanine aminotransferase increase, anemia, and hyponatremia), and no grade ≥ 4 treatment-related adverse events occurred. Five patients (12.5%) had an immune-related adverse event (all grade 1/2). CONCLUSIONS: Avelumab showed acceptable safety in Japanese patients with advanced solid tumors and clinical activity in patients with advanced gastric cancer/gastroesophageal junction cancer and disease progression after chemotherapy.

Phase I dose-escalation trial of Sym004, an anti-EGFR antibody mixture, in Japanese patients with advanced solid tumors.

Sym004 is a 1:1 mixture of two antibodies targeting non-overlapping epitopes of the epidermal growth factor receptor that antagonizes ligand binding and induces receptor downregulation. In preclinical models, it has superior antitumor activity to cetuximab and panitumumab. Japanese adults aged ≥20 years with an Eastern Cooperative Oncology Group status of 0/1 and life expectancy ≥3 months were eligible. Patients in Part A (dose escalation) had refractory or recurrent late-stage solid tumors and received Sym004 6 mg/kg/wk (n = 3), 9 mg/kg loading/6 mg/kg/wk (n = 6), 12 mg/kg/wk (n = 6), or 18 mg/kg biweekly (n = 6). Patients in expansion Part B (n = 30) had esophageal squamous cell carcinoma and received Sym004 at the dose recommended from Part A. Fifty-one patients received Sym004. No dose-limiting toxicities were observed in Part A. A dose of 12 mg/kg/wk was selected for Part B. All patients in Part B experienced treatment-related adverse events, most commonly dermatitis acneiform (76.7%). Eighteen grade ≥3 treatment-related adverse events and five serious adverse events occurred (cardiac arrest, lung infection, interstitial lung disease, toxic skin eruption, blood creatinine increase). Two patients had treatment-related adverse events resulting in death (cardiac arrest and blood creatinine increase). Five patients in Part B had a best overall response of partial response, 12 stable diseases and 12 disease progression (1 not evaluable). The objective response rate was 16.7% (95% CI: 5.6%-34.7%). Sym004 therapy was well tolerated with no dose-limiting toxicities at any dose studied. Evidence of antitumor activity was seen in patients with esophageal squamous cell carcinoma. ClinicalTrials.gov Identifier: NCT01955473.

Coexpression of IL-18 strongly attenuates IL-12-induced systemic toxicity through a rapid induction of IL-10 without affecting its antitumor capacity.

IL-12 is an excellent candidate for the treatment of cancer due to its ability to drive strong antitumor responses. Recombinant IL-12 protein is currently used in cancer patients; however, systemic expression of rIL-12 presents disadvantages including cost and dose limitation due to its toxicity. In this study, we used hydrodynamic shear of cDNA as a tool to achieve systemic expression of IL-12. We found that sustained but toxic levels of serum IL-12 could be generated in 6- to 7-wk-old B6 mice after a single injection of the cDNA. Unexpectedly, we observed that when IL-12 cDNA is coinjected with IL-18 cDNA, IL-12 antitumor activity was maintained, but there was a significant attenuation of IL-12 toxicity, as evidenced by a greater survival index and a diminution of liver enzymes (ALT and AST). Interestingly, after IL-12 plus IL-18 cDNA administration, more rapid and higher IL-10 levels were observed than after IL-12 cDNA treatment alone. To understand the mechanism of protection, we coinjected IL-12 plus IL-10 cDNAs and observed an increase in survival that correlated with diminished serum levels of the inflammatory cytokines TNF-alpha and IFN-gamma. Confirming the protective role of early IL-10 expression, we observed a significant decrease in survival in IL-10 knockout mice or IL-10R-blocked B6 mice after IL-12 plus IL-18 treatment. Thus, our data demonstrate that the high and early IL-10 expression induced after IL-12 plus IL-18 cDNA treatment is critical to rapidly attenuate IL-12 toxicity without affecting its antitumor capacity. These data could highly contribute to the design of more efficient/less toxic protocols for the treatment of cancer.

A highly bone marrow metastatic murine breast cancer model established through in vivo selection exhibits enhanced anchorage-independent growth and cell migration mediated by ICAM-1.

To understand the mechanisms underlying bone marrow metastasis precisely, we established the highly metastatic 4T1E/M3 murine breast cancer cell line. 4T1 murine breast cancer cells were transfected with the neomycin resistance gene, selected in G418, intravenously injected into mice, and harvested from bone marrow. By repeating this protocol three times, we established the 4T1E/M3 cells. The clonality of 4T1E/M3 cells was markedly high confirmed by genomic southern analysis using neo-gene probe. When tissues harvested from mice after intravenous injection of 4T1E/M3 cells were examined histologically, markedly enhanced bone marrow metastasis was observed; 77% of spines from 4T1E/M3-injected mouse showed metastasis as compared to 14% metastasis seen with the parent cells. In vitro, 4T1E/M3 cells attached more strongly to the plastic plate and to bone marrow-derived endothelial cells. DNA micro arrays, real time RT-PCR and FACS analyses revealed that the expression of ICAM-1 and beta2 integrin was upregulated in 4T1E/M3 cells at both the mRNA and cell surface protein levels. 4T1E/M3 cells also showed greater anchorage-independent proliferation in soft agar, and migrated markedly faster than the parent cells in wound healing assays. Anti-ICAM-1 antibodies strongly inhibited both the colony formation and the migration activity of 4T1E/M3 suggesting the importance of the role of ICAM-1. Our newly established highly metastatic 4T1E/M3 cells may provide a potentially powerful tool to study the molecular mechanisms of bone marrow metastasis and to identify new molecular targets for therapeutic interventions.

Metastasis-associated gene expression profile of liver and subcutaneous lesions derived from mouse pheochromocytoma cells.

The development of metastatic cancer is associated with overexpression or downregulation of specific genes and cell regulatory pathways. Some of these genes and pathways may be involved in invasion and dissemination of tumor cells, while others may promote seeding, survival or growth of cells at specific distant sites. In this investigation, gene expression profiles of nonmetastasizing tumors generated by injecting mouse pheochromocytoma cells (MPCs) subcutaneously were compared to those of liver tumors generated by injecting the cells intravenously. Both were compared to the cultured parental cell line. Tumors in the liver have a route of spread, anatomical distribution, and growth environment similar to naturally metastasizing pheochromocytomas, while intravenous injection of cells bypasses the initial steps of metastasis occurring spontaneously from a primary tumor. Eight genes were upregulated in liver tumors, 15 in subcutaneous tumors and seven in both compared to the cultured cells. Using quantitative real-time PCR, expression of five genes (Metap2, Reck, S100a4, Timp2, and Timp3) was verified as significantly lower in liver tumors than in subcutaneous tumors. Downregulation of these genes has been previously been associated with malignancy of pheochromocytomas. These findings indicate that different microenvironments can differentially affect the expression of metastasis-related genes in pheochromocytomas, and that overexpression or underexpression of these genes need not be present when the tumor cells are initially disseminated. The hepatic localization of tumors formed by intravenously injected MPC cells and the tumors' gene expression profile resembling that of naturally occurring pheochromocytoma metastases support the use of this model to study pheochromocytoma metastasis.

Phase I/II study of tecemotide as immunotherapy in Japanese patients with unresectable stage III non-small cell lung cancer.

OBJECTIVES: Unresectable stage III NSCLC (non-small cell lung cancer) confers a poor prognosis and interest is growing in the use of immunotherapy to improve outcomes for patients with this disease. We investigated the safety and efficacy of maintenance tecemotide, a mucin 1 (MUC1)-specific agent that induces T-cell responses to MUC1, versus placebo in Japanese patients with stage III unresectable NSCLC and no disease progression after primary chemoradiotherapy. MATERIALS AND METHODS: Patients aged ≥20 years with unresectable stage III NSCLC, stable disease or clinical response after primary chemoradiotherapy and performance status ≤1, were recruited across 25 centers in Japan. Patients were randomized 2:1 to tecemotide (930µg as lipopeptide) or placebo subcutaneously once weekly for 8 weeks, then every 6 weeks until disease progression or treatment withdrawal. Cyclophosphamide 300mg/m2 (maximum dose 600mg) was given intravenously 3days before the first dose of tecemotide. The primary endpoint was overall survival (OS). Secondary endpoints were progression-free survival, time to progression, time to treatment failure and safety. RESULTS: The intent-to-treat population comprised 172 patients; 114 received tecemotide and 58 placebo. Baseline characteristics were comparable between treatment arms. Most patients (94%) received primary concurrent chemoradiotherapy. There was no apparent trend toward increased OS time with tecemotide over placebo (median 32.4 versus 32.2 months, hazard ratio 0.95, 95% confidence interval 0.61-1.48; P=0.83). No improvements in secondary efficacy endpoints were observed. The frequency of treatment-related adverse events was similar, and serious adverse event rates were the same in both arms. There were no new safety signals. CONCLUSIONS: These results do not support those from a randomized phase III study (START) of improved OS with tecemotide in the subgroup of patients treated with primary concurrent chemoradiotherapy.

Structure and characterization of hamster IL-12 p35 and p40.

Complementary DNAs coding for two subunits of hamster interleukin-12 (IL-12), p35 and p40, were cloned from a hamster dendritic cell (DC) cDNA library. The cloning demonstrated that hamster IL-12 consisted of a p35 subunit with 216 amino acid (aa) residues and a p40 subunit with 327 aa. Structural comparison of hamster p35 and p40 at the protein level showed the highest homologies with each counterpart of sigmodon (hispid cotton rat). The gene expressions of hamster IL-12 p35 and p40 in bone marrow (BM) cells cultured in the presence of mouse granulocyte macrophage-colony-stimulating factor (mGM-CSF) and IL-4 were up-regulated during culture. Immunoblot analysis of 293 cells transfected with hamster p35 and p40 expression vectors suggested the presence of a covalently linked p35/p40 heterodimer. Furthermore, supernatant from the 293 cells transfected with both expression vectors induced the up-regulation of interferon-gamma (IFN-gamma) mRNA in hamster splenocytes, indicating that the p35/p40 heterodimer IL-12 protein present in the supernatant was functional. These results suggest that the vectors containing hamster IL-12 cDNA might be suitable tools for developing an immunotherapeutic approach against experimental cancer in a hamster model.

Retroviral-mediated IL-12 gene transduction into human CD34+ cell-derived dendritic cells.

Genetically modified dendritic cells (DCs) with Th1 type cytokine genes are useful for activating anti-tumor immune response. We made human interleukin (IL)-12 p70 gene-transduced DCs generated from CD34+ progenitor cells using a retrovirus system and investigated the function of IL-12-producing DCs. We used the pMX retroviral vector and made cytokine gene-containing viral vectors referred to as GFP pMX and hIL-12 pMX. Supernatants from BOSC23 cells transfected with GFP pMX and hIL-12 pMX were harvested and used for transfection of DC. Cord blood CD34+ cells were incubated with supernatants containing retrovirus for 48 h with cytokines such as IL-3, IL-6, SCF, Flt3 ligand (FL), bFGF and IGF-I. The cells were cultured for 12 days in the presence of GM-CSF, SCF, FL, IL-4 and TNF-alpha to get mature DC-enriched population. Analysis of surface marker on DCs and allogeneic MLR assay were also performed. After a 14-day culture, 60-70% of cultured CD34+ cells were DC marker (CD1a, DEC205) positive. The IL-12 p70 protein levels in supernatant of DC-GFP and DC-hIL-12 were 0.2 ng/ml and 53 ng/ml/5 x 10(5) DCs for 72 h, respectively. The addition of CH296 fibronectin fragment (FN) increased 3-fold IL-12 gene transduction efficiency into DCs. MLR assay showed that IL-12-producing DC exhibited more potent T cell growth-stimulating activity compared with GFP-DC. These results suggested that genetically modified CD34+ cell-derived DCs with human IL-12 gene are fully efficient in T cell priming, and could be a good tool for effective cancer immunotherapy.

Flt3 ligand enhances anti-tumor effects of antibody therapeutics.

Fms-like tyrosine kinase 3 ligand ([Flt3 ligand], FL) stimulates proliferation and development of a wide range of hematopoietic cells including hematopoietic stem cells and myeloid and lymphoid progenitor cells. FL also has been shown to have anti-tumor effects in a variety of in vivo tumor models. In this study, the effect of FL against tumor growth was investigated in the COLO-205 human colon tumor xenograft model. FL was delivered in vivo by the "hydrodynamics-based gene delivery of naked DNA" method. In this experimental setting, FL and/or the therapeutic antibody anti-carcinoembryonic antigen (CEA) monoclonal antibody was administered. FL alone or anti-CEA antibody alone induced significant growth inhibition; furthermore, FL plus antibody treatment produced synergistic anti-tumor effects. This study is the first demonstration of a synergistic anti-tumor effect between FL and antibody therapeutics.

Chemokine CCL2/MCP-1 negatively regulates metastasis in a highly bone marrow-metastatic mouse breast cancer model.

Bone is the most frequent site of breast cancer metastasis, and once such metastasis occurs, complete remission is extremely difficult to achieve. In an effort to define the mechanisms underlying metastatic spread of breast cancer to bone, we previously developed and characterized the highly bone metastatic 4T1E/M3 mouse breast cancer cells. We found that following injection into mice, 4T1E/M3 cells exhibited greater bone metastasis and greater in vitro anchorage-independent growth and cell migration than their parental cells (4T1E). We also found that expression of intracellular adhesion molecule-1 (ICAM-1) is crucially involved in these metastatic activities of 4T1E/M3 cells. In the present study, our analysis of gene and protein expression revealed that production of chemokine CCL2 (MCP-1) is dramatically reduced in 4T1E/M3 cells, and that restoration of CCL2 expression in 4T1E/M3 cells diminishes their metastasis to bone and lung. Overexpression of CCL2 in 4T1E/M3 cells significantly reduced not only in vitro anchorage-independent cell growth and cell migration, but also mRNA and cell surface expression of ICAM-1. Conversely, knocking down CCL2 in 4T1E parental cells augmented their metastatic spread to spine and lung. The expression of ICAM-1 was also upregulated in 4T1E-derived CCL2 knockdown cells. Taken together, these results suggest that CCL2 expression may negatively regulate breast cancer metastasis to bone marrow and lung in our model and that expression of ICAM-1 plays a crucial role in that process.

Endogenous IL-12 triggers an antiangiogenic program in melanoma cells.

The IL12RB2 gene acts as a tumor suppressor in human B cell malignancies. Indeed, Il12rb2 knockout (KO) mice develop spontaneously B cell tumors, but also lung epithelial tumors. This latter phenotype may be related to (i) impairment of host IL-12-mediated immunosurveillance and/or (ii) IL-12 inability to inhibit directly the growth of IL-12 unresponsive malignant cells. To address this issue, we transplanted IL-12R(+) B16 melanoma cells into syngeneic Il12rb2 KO mice with the following rationale: (i) these mice have severe defects in IFN-gamma production, as well as in cytotoxic T lymphocyte and natural killer cell cytotoxicity, and (ii) they produce but do not use IL-12 that can potentially bind to and target tumor cells only. Il12rb2 KO mice displayed higher endogenous serum levels of IL-12 and developed smaller B16 tumors than WT animals. These tumors showed reduced proliferation, increased apoptosis, and defective microvessel formation related to down-regulated expression of a set of proangiogenic genes previously unrelated to IL-12. Such effects depended on direct activity of endogenous IL-12 on tumor cells in KO mice, and hydrodynamic delivered IL-12 caused further reduced tumorigenicity of B16 cells in these mice. A previously undescribed mechanism of the IL-12 antitumor activity has been here identified and characterized.

In vivo hydrodynamic delivery of cDNA encoding IL-2: rapid, sustained redistribution, activation of mouse NK cells, and therapeutic potential in the absence of NKT cells.

In the present study, we have tested the ability of hydrodynamically delivered IL-2 cDNA to modulate the number and function of murine leukocyte subsets in different organs and in mice of different genetic backgrounds, and we have evaluated effects of this mode of gene delivery on established murine tumor metastases. Hydrodynamic administration of the IL-2 gene resulted in the rapid and transient production of up to 160 ng/ml IL-2 in the serum. The appearance of IL-2 was followed by transient production of IFN-gamma and a dramatic and sustained increase in NK cell numbers and NK-mediated cytolytic activity in liver and spleen leukocytes. In addition, significant increases in other lymphocyte subpopulations (e.g., NKT, T, and B cells) that are known to be responsive to IL-2 were observed following IL-2 cDNA plasmid delivery. Finally, hydrodynamic delivery of only 4 mug of the IL-2 plasmid to mice bearing established lung and liver metastases was as effective in inhibiting progression of metastases as was the administration of large amounts (100,000 IU/twice daily) of IL-2 protein. Studies performed in mice bearing metastatic renal cell tumors demonstrated that the IL-2 cDNA plasmid was an effective treatment against liver metastasis and moderately effective against lung metastasis. Collectively, these results demonstrate that hydrodynamic delivery of relatively small amounts of IL-2 cDNA provides a simple and inexpensive method to increase the numbers of NK and NKT cells, to induce the biological effects of IL-2 in vivo for use in combination with other biological agents, and for studies of its antitumor activity.