Nivolumab versus irinotecan as third- or later-line treatment for advanced gastric cancer: a multi-center retrospective study.

BACKGROUND: The present study aimed to compare the efficacy and safety of nivolumab (NIVO) and irinotecan (IRI) and to identify clinical factors that facilitate treatment selection. METHODS: Patients with advanced gastric cancer (AGC) who underwent NIVO or IRI treatment between November 2016 and June 2018 at three institutions were retrospectively reviewed. The inclusion criteria were histologically confirmed gastric/gastroesophageal adenocarcinoma pretreated with fluoropyrimidines and taxanes, no previous NIVO or IRI treatment, and adequate organ function. Main outcome measures were objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and adverse events. Interaction between treatment groups and clinical factors regarding OS were tested using a multivariate Cox proportional hazards model adjusted for relevant variables. RESULTS: Both NIVO (n = 71) and IRI (n = 61) groups had similar baseline characteristics, except for sex distribution. NIVO and IRI groups had ORR of 20% and 6%, median PFS of 1.6 and 1.8 months, and median OS of 6.4 and 6.4 months, respectively. Interaction analysis did not reveal any significant interaction between NIVO and IRI related to OS for various factors. NIVO group tended to have fewer ≥ grade 3 adverse events than IRI group, especially neutropenia (3% vs. 28%) and febrile neutropenia (1% vs. 8%). In the NIVO group, one patient developed pneumonitis, and four patients developed skin reactions. CONCLUSIONS: Although no remarkable differences in efficacy were found between IRI and NIVO for AGC, NIVO had a better safety profile compared to IRI. We found no clinical markers that can assist treatment decisions.

Prognostic Factors in Patients with Advanced HER2-Positive Gastric Cancer Treated with Trastuzumab-Based Chemotherapy: a Cohort Study.

PURPOSE: Prognostic factors for the survival of patients with advanced HER2-positive gastric cancer treated with trastuzumab-based chemotherapy remain controversial. The aim of this study was to identify the clinical factors that predict prognosis in patients with advanced HER2-positive gastric cancer. METHODS: We retrospectively reviewed the medical records of HER2-positive gastric cancer patients treated with trastuzumab-based chemotherapy at our institution. Clinical features and laboratory test results that considered prognostic factors were re-examined. Overall survival (OS) was estimated using the Kaplan-Meier method. Univariate analysis was performed with the log-rank test and multivariate analysis was performed using Cox's proportional hazard regression model. RESULTS: A total of 133 patients with advanced HER2-positive gastric cancer were enrolled. The median OS in this cohort was 18.7 months. Four prognostic factors: visceral metastasis (lung or liver), levels of hemoglobin (Hb) (< 11.6 g/dl), lactate dehydrogenase (LDH) (> 222 mg/dl), and C-reactive protein (CRP) (> 0.14 mg/dl), were identified as independent prognostic factors. The patients were placed into three groups according to their number of prognostic factors. These included low (0, 1), moderate (2, 3), and high (4) risk factors. The OS was separated into three categories with a median OS of 32.0, 18.7, and 10.1 months, respectively. Compared to the low-risk group, hazard ratios for the moderate- and high-risk groups were 1.75 and 3.49, respectively. CONCLUSION: Visceral metastasis and abnormal Hb, LDH, and CRP levels were associated with unfavorable OS. These findings may be beneficial for the management of advanced HER2-positive gastric cancer treated with trastuzumab-based chemotherapy.

ER-851, a Novel Selective Inhibitor of AXL, Overcomes Resistance to Antimitotic Drugs.

Innate and adaptive resistance to cancer therapies, such as chemotherapies, molecularly targeted therapies, and immune-modulating therapies, is a major issue in clinical practice. Subpopulations of tumor cells expressing the receptor tyrosine kinase AXL become enriched after treatment with antimitotic drugs, causing tumor relapse. Elevated AXL expression is closely associated with drug resistance in clinical samples, suggesting that AXL plays a pivotal role in drug resistance. Although several molecules with AXL inhibitory activity have been developed, none have sufficient activity and selectivity to be clinically effective when administered in combination with a cancer therapy. Here, we report a novel small molecule, ER-851, which is a potent and highly selective AXL inhibitor. To investigate resistance mechanisms and identify driving molecules, we conducted a comprehensive gene expression analysis of chemoresistant tumor cells in mouse xenograft models of genetically engineered human lung cancer and human triple-negative breast cancer. Consistent with the effect of AXL knockdown, cotreatment of ER-851 and antimitotic drugs produced an antitumor effect and prolonged relapse-free survival in the mouse xenograft model of human triple-negative breast cancer. Importantly, when orally administered to BALB/c mice, this compound did not induce retinal toxicity, a known side effect of chronic MER inhibition. Together, these data strongly suggest that AXL is a therapeutic target for overcoming drug resistance and that ER-851 is a promising candidate therapeutic agent for use against AXL-expressing antimitotic-resistant tumors.

Discovery of 5,6,7,8-tetrahydropyrido[3,4-d]pyrimidine derivatives as novel selective Axl inhibitors.

Axl and Mer are members of the TAM (Tyro3-Axl-Mer) family of receptor tyrosine kinases. Previously, we reported that enzyme-mediated inhibition of Mer by an Axl/Mer dual inhibitor led to retinal toxicity in mice, whereas selective Axl inhibition by compound 1 did not. On the other hand, compound 1 showed low membrane permeability. Here, we designed and synthesized a novel series of 5,6,7,8-tetrahydropyrido[3,4-d]pyrimidine derivatives and evaluated their Axl and Mer inhibitory activities, leading to identification of ER-001259851-000 as a potent and selective Axl inhibitor with drug-likeness and a promising pharmacokinetic profile in mice.

Discovery of a potent and selective Axl inhibitor in preclinical model.

Axl and Mer are a members of the TAM (Tyro3-Axl-Mer) family of receptor tyrosine kinases, which, when activated, can promote tumor cell survival, proliferation, migration, invasion, angiogenesis, and tumor-host interactions. Chronic inhibition of Mer leads to retinal toxicity in mice. Therefore, successful development of an Axl targeting agent requires ensuring that it is safe for prolonged treatment. Here, to clarify whether enzyme inhibition of Mer by a small molecule leads to retinal toxicity in mice, we designed and synthesized Axl/Mer inhibitors and Axl-selective inhibitors. We identified an Axl/Mer dual inhibitor 28a, which showed retinal toxicity at a dose of 100 mg/kg in mice. Subsequent derivatization of a pyridine derivative led to the discovery of a pyrimidine derivative, 33g, which selectively inhibited the activity of Axl over Mer without retinal toxicity at a dose of 100 mg/kg in mice. Additionally, the compound displayed in vivo anti-tumor effects without influencing body weight in a Ba/F3-Axl isogenic subcutaneous model.

An observational study on nutrition status in gastric cancer patients receiving ramucirumab plus taxane: BALAST study.

Limited data are available regarding the efficacy of nutrition support in advanced gastric cancer (AGC) patients receiving a standard second-line combination chemotherapy. The BALAST study is conducted as a prospective, multicenter observational study to evaluate the efficacy of nutrition support for patients with AGC treated with ramucirumab plus taxane as second-line treatment. As part of the routine care, patients who are malnourished or at risk of malnutrition will receive nutrition support from dietitians. We will enroll a total of 26 patients to estimate weight control rate at 12 weeks as primary end point. This study will generate valuable data reinforcing the role of nutrition support therapy for AGC patients receiving second-line chemotherapy.

Lay abstract Various guidelines recommend that nutrition support therapy should be considered if cancer patients are malnourished or at risk of malnutrition. Several studies have revealed that body weight loss, which is an important factor in determining the nutrition status, may predict survival during second-line standard chemotherapy with ramucirumab and a taxane for advanced gastric cancer (AGC) patients. However, limited data are available regarding the efficacy of nutrition support in AGC patients receiving ramucirumab and a taxane. This study is conducted as a prospective, multicenter observational study to evaluate the efficacy of nutrition support for Japanese patients with AGC treated with ramucirumab and a taxane. This study will generate valuable data reinforcing the role of nutrition support therapy for AGC patients in second-line treatment. Clinical trial registration: UMIN000037867.

E7386, a Selective Inhibitor of the Interaction between ß-Catenin and CBP, Exerts Antitumor Activity in Tumor Models with Activated Canonical Wnt Signaling.

The Wnt/ß-catenin signaling pathway plays crucial roles in embryonic development and the development of multiple types of cancer, and its aberrant activation provides cancer cells with escape mechanisms from immune checkpoint inhibitors. E7386, an orally active selective inhibitor of the interaction between ß-catenin and CREB binding protein, which is part of the Wnt/ß-catenin signaling pathway, disrupts the Wnt/ß-catenin signaling pathway in HEK293 and adenomatous polyposis coli (APC)-mutated human gastric cancer ECC10 cells. It also inhibited tumor growth in an ECC10 xenograft model and suppressed polyp formation in the intestinal tract of ApcMin /+ mice, in which mutation of Apc activates the Wnt/ß-catenin signaling pathway. E7386 demonstrated antitumor activity against mouse mammary tumors developed in mouse mammary tumor virus (MMTV)-Wnt1 transgenic mice. Gene expression profiling using RNA sequencing data of MMTV-Wnt1 tumor tissue from mice treated with E7386 showed that E7386 downregulated genes in the hypoxia signaling pathway and immune responses related to the CCL2, and IHC analysis showed that E7386 induced infiltration of CD8+ cells into tumor tissues. Furthermore, E7386 showed synergistic antitumor activity against MMTV-Wnt1 tumor in combination with anti-PD-1 antibody. In conclusion, E7386 demonstrates clear antitumor activity via modulation of the Wnt/ß-catenin signaling pathway and alteration of the tumor and immune microenvironments, and its antitumor activity can be enhanced in combination with anti-PD-1 antibody. SIGNIFICANCE: These findings demonstrate that the novel anticancer agent, E7386, modulates Wnt/ß-catenin signaling, altering the tumor immune microenvironment and exhibiting synergistic antitumor activity in combination with anti-PD-1 antibody.

Chemoradiotherapy with FOLFOX for esophageal squamous cell cancer with synchronous rectal cancer: Four case reports and a literature review.

Chemoradiotherapy (CRT) is a valuable treatment option for localized esophageal cancer. Conventional baseline chemotherapy for this type of cancer includes cisplatin and fluorouracil. Recently, CRT with leucovorin-fluorouracil-oxaliplatin (FOLFOX) has become popular due to its convenience and lower toxicity. In Japan, the use of oxaliplatin for esophageal cancer is not yet approved, so experience with this treatment is limited to cases with colorectal cancer. As such patients are not usually included in clinical trials, little is known on the efficacy and safety of this treatment for this patient subpopulation, and treatment generalization in Japan is not allowed. We herein share our experience with CRT and FOLFOX for cases with esophageal cancer and synchronous rectal cancer at our institution. The clinical data of 4 patients who were treated for esophageal cancer with CRT/FOLFOX at our hospital between 2007 and 2016, who also had synchronous rectal cancer, were retrieved and analyzed. All the patients were male and had esophageal squamous cell cancer and synchronous rectal cancer. The median patient age was 68 years (range, 65-77 years). One patient received neoadjuvant CRT followed by surgery, and the other 3 patients received definitive CRT for esophageal cancer. FOLFOX was administered biweekly during radiotherapy (41.4-60 Gy). All 4 patients completed the treatment schedule and responded to CRT. No patients experienced progression of rectal cancer during treatment. Notably, 1 patient also achieved a complete response (CR) of rectal cancer after CRT for esophageal cancer. Moreover, 2 patients without dysphagia were treated as outpatients and achieved a CR. Encephalopathy was the only reported grade 3 adverse event. Although the present study included a limited number of cases, the findings suggest that CRT with FOLFOX may be a valuable option for the treatment of patients with esophageal squamous cell cancer and synchronous rectal cancer.

Early hypertension is associated with better clinical outcomes in gastric cancer patients treated with ramucirumab plus paclitaxel.

Anti-vascular endothelial growth factor (VEGF) therapeutics such as bevacizumab, which are widely used in cancer treatment, commonly leads to hypertension. Moreover, bevacizumab-induced hypertension is associated with improved clinical outcomes in several cancers. We retrospectively analyzed 89 patients with histologically confirmed advanced gastric cancer who received the human monoclonal anti-VEGF receptor-2 antibody ramucirumab plus paclitaxel at our hospital between June 2015 and October 2016 to evaluate the impact of treatment-associated hypertension occurring within the first two treatment cycles ("early hypertension") on outcome. The objective response rate was 40%, median progression-free survival was 5.4 months, and overall survival was 10.4 months, which is similar to previous reports. Early hypertension in patients who received more than two cycles of ramucirumab + paclitaxel was associated with longer progression-free and overall survival. Objective response rates were also higher in patients with early hypertension. These data indicate that early hypertension may be predictive of better outcomes in gastric cancer patients who receive ramucirumab + paclitaxel treatment.

Clinical impact of intratumoral HER2 heterogeneity on trastuzumab efficacy in patients with HER2-positive gastric cancer.

BACKGROUND: There is growing interest in the clinical significance of intratumoral HER2 heterogeneity. Its prognostic and predictive impacts on trastuzumab efficacy were demonstrated in breast cancer. However, its clinical significance in gastric cancer is still unclear. METHODS: Twenty-eight HER2-positive gastric cancer patients who had gastrectomy prior to trastuzumab-based chemotherapy were consecutively enrolled. Intratumoral HER heterogeneity was evaluated using whole-tissue sections by immunohistochemistry. When all tumor cells overexpressed HER2 protein, the tumor was defined as homogeneously HER2 (Homo-HER2)-positive group. The others were defined as heterogeneously HER2 (Hetero-HER2)-positive group. RESULTS: There was no significant difference in clinicopathological features between the two groups. The median progression-free survival (PFS) and overall survival (OS) in the Homo-HER2-positive group were significantly longer than those in the Hetero-HER2-positive group (PFS; 20.0 months [95% CI 17.8-22.2] vs. 6.0 months [95% CI 2.3-9.7]; HR 0.11; 95% CI 0.03-0.41; p < 0.001, OS; not reached vs. 14.0 months [95% CI 11.9-16.1]; HR 0.18; 95% CI 0.06-0.61; p = 0.003). In the multivariate analysis, these associations remained significant both in PFS (HR 0.12; 95% CI 0.03-0.46, p = 0.002) and OS (HR 0.21; 95% CI 0.06-0.72, p = 0.013). With respect to response rate, no statistical difference was found between two groups. However, deeper tumor shrinkage was obtained in the Homo-HER2-positive group compared with the Hetero-HER2-positive group (p = 0.046). CONCLUSIONS: Intratumoral HER2 heterogeneity may have robust clinical impact on trastuzumab efficacy in patients with HER2-positive gastric cancer. These findings should be validated by larger independent cohorts and further molecular correlative analyses are warranted.

A retrospective analysis of ramucirumab monotherapy in previously treated Japanese patients with advanced or metastatic gastric adenocarcinoma.

BACKGROUND: The REGARD trial demonstrated that ramucirumab monotherapy improved both overall survival (OS) and progression-free survival (PFS) compared with best supportive care plus placebo as second-line treatment for patients with advanced gastric cancer. However, the efficacy and safety of ramucirumab monotherapy for previously treated Japanese patients with advanced gastric cancer remains unknown. METHODS: Previously treated Japanese patients with advanced gastric cancer who received ramucirumab monotherapy between June 2015 and March 2016 at the Cancer Institute Hospital were enrolled in the study. OS, PFS, best overall response, and safety profiles were retrospectively evaluated. RESULTS: Nineteen patients were enrolled in this study. Ramucirumab monotherapy was generally administered as third-line therapy. After a median follow-up period of 7.4 months, the median PFS was 2.1 months (95% CI 1.0-3.5), and median OS was 12.9 months (95% CI 2.3, not reached). In 13 patients who had measurable lesions on radiologic examination, partial response was observed in one patient (7.7%) and stable disease was observed in five patients (38.5%). A total of 12 patients (63.2%) had adverse events (AEs). Common AEs included hypertension (8 patients, 42.1%), fatigue (6 patients, 31.6%), and bleeding (5 patients, 26.3%). Grade 3 AEs included gastrointestinal bleeding and aspiration pneumonia (1 patient each, 5.3%). CONCLUSIONS: Our data suggest that ramucirumab monotherapy in Japanese patients with previously treated advanced gastric cancer has comparable efficacy and safety profiles as reported in the REGARD trial.

Associations between early tumor shrinkage and depth of response and clinical outcomes in patients treated with 1st-line chemotherapy for advanced gastric cancer.

BACKGROUND: Although early tumor shrinkage (ETS) predictions of the efficacy and depth of response (DpR) reflects clinical outcomes in chemotherapy with epidermal growth factor receptor inhibitor regimens to treat metastatic colorectal cancer, their value in assessing treatments for advanced gastric cancer (AGC) is unclear. Here we evaluated relationships between ETS and DpR and clinical outcomes in AGC patients treated with first-line chemotherapy. METHODS: We retrospectively enrolled 612 consecutive patients treated with first-line chemotherapy for AGC between January 2010 and June 2016. ETS and DpR were defined as changes from baseline in summed longest diameters in target lesions at 8 (±4) weeks for ETS and at the smallest observed volume for DpR. RESULTS: Eligible patients were sorted into HER2+ (n = 100) and HER2- (n = 186) groups. Median follow-up was 14.8 months. The overall response rate and disease control rates were 64 and 87% in the HER2+ group and 53.2 and 86.0% in the HER2- group. Respective median PFS and OS were HER2+: 7.9 and 20.8 months and HER2-: 6.6 and 13.8 months. The respective ETS rate and median DpR were HER2+: 70 and 44% and HER2-: 57.5 and 24%. Clinical outcomes and ETS/DpR were correlated, especially in the HER2+ group (OS: P < 0.0001; PFS: P < 0.0001). In multivariate analysis, ETS was an independent predictor for OS in the HER2+ group and for PFS in both groups. CONCLUSION: These results indicate that ETS may be an early-on treatment predictor of the efficacy of HER2+ advanced gastric cancer treated with first-line chemotherapy that includes trastuzumab.

Retrospective comparison of S-1 plus cisplatin versus S-1 monotherapy for the treatment of advanced gastric cancer patients with positive peritoneal cytology but without gross peritoneal metastasis.

BACKGROUND: Peritoneal cytology positive for carcinoma cells (CY+) is an independent poor prognostic factor in gastric cancer, and patients with CY+ are diagnosed with stage IV disease. However, there is no standard treatment strategy for CY+ gastric cancer, whereas combination chemotherapy with fluoropyrimidine and platinum has been established as the standard treatment for unresectable advanced gastric cancer or after R2 resection. Herein, we assessed whether adding cisplatin to S-1 (SP) could improve the outcome of CY+ gastric cancer patients, as compared to S-1 monotherapy. METHODS: This retrospective study was conducted at a single Japanese institute between June 2005 and March 2014. Patients diagnosed with CY+ advanced gastric cancer and treated with S-1-based therapy were enrolled. Patients with incurable factors other than CY+ were excluded. RESULTS: Forty-four patients were enrolled; 25 and 19 were administered S-1 and SP, respectively. The 2-year survival rates were 52.0% [95% confidence interval (CI), 31.2-69.2%] and 52.6% (28.7-71.9%) in the S-1 and SP groups, respectively. The median overall survival (OS) and progression-free survival (PFS) were 28.2 and 15.6 months in the S-1 group and 24.0 and 18.8 months in the SP group, respectively; they were not significantly different. The relative dose intensities were 0.79 (S-1) in the S-1 group and 0.69 (S-1)/0.70 (cisplatin) in the SP group. CONCLUSION: Adding cisplatin to long-term S-1 monotherapy did not significantly improve the outcome of CY+ advanced gastric cancer patients.

Efficacy and safety of taxane monotherapy in advanced gastric cancer refractory to triplet chemotherapy with docetaxel, cisplatin, and S-1: a multicenter retrospective study.

PURPOSE: Taxane monotherapy is widely used for advanced gastric cancer (AGC) after failure of standard first-line chemotherapy with fluoropyrimidine and cisplatin. Triplet chemotherapy with docetaxel, cisplatin, and S-1 (DCS) is a promising regimen for first-line chemotherapy of AGC. The aim of this study was to evaluate the efficacy of taxane monotherapy in patients refractory to DCS. METHODS: We retrospectively evaluated the efficacy and safety of taxane monotherapy in patients with AGC refractory to first-line therapy with DCS between January 2010 and April 2015. Selection criteria were as follows: ECOG PS of 0-2, treatment with taxane monotherapy in second-line or third-line therapy after failure of second-line irinotecan, absence of massive ascites, and adequate organ function. RESULTS: A total of 30 patients were included in this study. Of these, 15 patients received paclitaxel while another 15 received nanoparticle albumin-bound paclitaxel in either second- or third-line treatment. Median age for the second/third-line group was 64.0/62.0 (range 27-75/42-75); 14/13 (93.3/86.7%) had ECOG PS of 0 or 1. No patients achieved complete or partial response and stable disease was observed in 37.5/35.7% of the patients in the second/third line. Median progression-free survival and overall survival were 3.4 and 5.8 months in the second-line group, and 2.0 and 4.5 months in the third-line group, respectively. The incidences of any grade ≥3 adverse events in the second-line group and the third-line group were 60.0 and 33.3%, respectively. There was no treatment-related death. CONCLUSIONS: Taxane monotherapy after DCS failure had acceptable toxicities but was ineffective in AGC patients.

Change in clinical outcomes during the transition of adjuvant chemotherapy for stage III colorectal cancer.

BACKGROUND: There are robust data supporting the contribution of oxaliplatin (L-OHP) regarding clinical outcomes for colorectal cancer (CRC) in an adjuvant setting in European and US trials; however, there is no Japanese clinical evidence although L-OHP has been approved since 2009. We examined the transition of adjuvant chemotherapy for stage III colorectal cancer in our institute. METHODS: A total of 642 patients with histopathologically confirmed stage III CRC underwent curative surgery from 2005 to 2010. We examined disease free survival (DFS), overall survival (OS) and prognostic factors for stage III CRC patients who underwent adjuvant chemotherapy. RESULTS: A total of 509 patients received adjuvant chemotherapy. 3-year DFS and 5-year OS rates were 74.5% and 87.5%, respectively. The frequency of inclusion of L-OHP as adjuvant chemotherapy was increased after 2008. A total of 189 patients received adjuvant chemotherapy from 2005 to 2007 increasing to 320 patients from 2008 to 2010; the 5-year OS rates were 82.4% and 91.5%, respectively, and the 3-year DFS rates were 69.2% and 76.6%, respectively (OS, P = 0.007; DFS, P = 0.023). In univariate analysis, adjuvant chemotherapy including L-OHP was no significant deference compared to FU monotherapy. (OS: HR 0.88, 95%CI 0.4-1.91, p = 0.75, DFS: HR 0.78, 95%CI 0.21-2.3, p = 0.29). In multivariate analysis, the OS was predicted by means of N stage (HR = 2; 95%CI, 1.1-3.8; P = 0.02) and pathology (HR = 0.28; 95%CI, 0.13-0.59; P = 0.0008). The DFS was predicted by means of N stage (HR = 2.67; 95%CI, 1.82-3.9; P < 0.05), T stage (HR = 1.61; 95%CI, 1.1-2.3; P = 0.01) pathology (HR = 0.47; 95%CI, 0.29-0.75; P < 0.05) and venous invasion (HR = 2.06; 95%CI, 1.12-3.77; P = 0.01). CONCLUSIONS: Clinical outcomes of stage III CRC patients receiving adjuvant chemotherapy improved. The frequency of L-OHP usage was increasing annually, however it was no influence for clinical outcomes in this study. It will be necessary to reevaluate additional effect of L-OHP with more patients.

Retrospective study of RAS/PIK3CA/BRAF tumor mutations as predictors of response to first-line chemotherapy with bevacizumab in metastatic colorectal cancer patients.

BACKGROUND: After analysis of minor RAS mutations (KRAS exon 3, 4/NRAS) in the FIRE-3 and PRIME studies, an expanded range of RAS mutations were established as a negative predictive marker for the efficacy of anti-EGFR antibody treatment. BRAF and PIK3CA mutations may be candidate biomarkers for anti-EGFR targeted therapies. However, it remains unknown whether RAS/PIK3CA/BRAF tumor mutations can predict the efficacy of bevacizumab in metastatic colorectal cancer. We assessed whether selection according to RAS/PIK3CA/BRAF mutational status could be beneficial for patients treated with bevacizumab as first-line treatment for metastatic colorectal cancer. METHODS: Of the 1001 consecutive colorectal cancer patients examined for RAS, PIK3CA, and BRAF tumor mutations using a multiplex kit (Luminex®), we studied 90 patients who received combination chemotherapy with bevacizumab as first-line treatment for metastatic colorectal cancer. The objective response rate (ORR) and progression-free survival (PFS) were evaluated according to mutational status. RESULTS: The ORR was higher among patients with wild-type tumors (64.3%) compared to those with tumors that were only wild type with respect to KRAS exon 2 (54.8%), and the differences in ORR between patients with wild-type and mutant-type tumors were greater when considering only KRAS exon 2 mutations (6.8%) rather than RAS/PIK3CA/BRAF mutations (18.4%). There were no statistically significant differences in ORR or PFS between all wild-type tumors and tumors carrying any of the mutations. Multivariate analysis revealed that liver metastasis and RAS and BRAF mutations were independent negative factors for disease progression after first-line treatment with bevacizumab. CONCLUSIONS: Patient selection according to RAS/PIK3CA/BRAF mutations could help select patients who will achieve a better response to bevacizumab treatment. We found no clinical benefit of restricting combination therapy with bevacizumab for metastatic colorectal cancer patients with EGFR-wild type tumors.

[Chemotherapeutic Strategies for Peritoneal Dissemination of Gastric Cancer].

The prognosis of unresectable or metastatic gastric cancer is poor. One of the reasons for this is peritoneal dissemination, which is often observed in gastric cancer. Here, we discuss some new therapeutic strategies, especially chemotherapeutic strategies, for peritoneal dissemination of gastric cancer. Occasionally, in cases of peritoneal dissemination, patients have severe ascites or bowel obstruction. For those who have such complications, treatment via chemotherapy including S-1, capecitabine, or cisplatin is inappropriate. Therefore, methotrexate plus 5-fluorouracil(5-FU), 5-FU continuous infusion, 5- FU plus l-levofolinate, or paclitaxel are generally administered to such patients. To improve the efficacy of chemotherapy for such patients, an ongoing clinical trial(JCOG1108)is comparing triplet chemotherapy(FLTAX)including 5-FU plus l-levofolinate plus paclitaxel with chemotherapy including 5-FU plus l-levofolinate. For gastric cancer with positive lavage cytology, S-1 monotherapy or S-1 plus cisplatin therapy are often used. However, till date there has been no prospective clinical trial that has evaluated the efficacy of these therapies in gastric cancer with peritoneal dissemination. Therefore, further clinical trials are warranted to evaluate which chemotherapy is more suitable for patients with gastric cancer with peritoneal dissemination. Moreover, the use of conventional combination chemotherapy and intraperitoneal(IP)chemotherapy for patients with gastric cancer with peritoneal dissemination is now under evaluation. At the latest ASCOmeeting, the results of the "PHOENIX-GC trial" were reported. In this trial, patients receiving IP paclitaxel, intravenous(IV)paclitaxel, and S-1(experimental arm)and those receiving S-1 plus cisplatin(control arm)were compared. Longer survival was observed in the IP paclitaxel group compared with the other groups; however, this difference did not reach statistical significance. We hope that the evaluation of data from clinical trials would result in the identification of the optimal treatment strategy for patients with gastric cancer with peritoneal dissemination.

E7090, a Novel Selective Inhibitor of Fibroblast Growth Factor Receptors, Displays Potent Antitumor Activity and Prolongs Survival in Preclinical Models.

The FGFR signaling pathway has a crucial role in proliferation, survival, and migration of cancer cells, tumor angiogenesis, and drug resistance. FGFR genetic abnormalities, such as gene fusion, mutation, and amplification, have been implicated in several types of cancer. Therefore, FGFRs are considered potential targets for cancer therapy. E7090 is an orally available and selective inhibitor of the tyrosine kinase activities of FGFR1, -2, and -3. In kinetic analyses of the interaction between E7090 and FGFR1 tyrosine kinase, E7090 associated more rapidly with FGFR1 than did the type II FGFR1 inhibitor ponatinib, and E7090 dissociated more slowly from FGFR1, with a relatively longer residence time, than did the type I FGFR1 inhibitor AZD4547, suggesting that its kinetics are more similar to the type V inhibitors, such as lenvatinib. E7090 showed selective antiproliferative activity against cancer cell lines harboring FGFR genetic abnormalities and decreased tumor size in a mouse xenograft model using cell lines with dysregulated FGFR Furthermore, E7090 administration significantly prolonged the survival of mice with metastasized tumors in the lung. Our results suggest that E7090 is a promising candidate as a therapeutic agent for the treatment of tumors harboring FGFR genetic abnormalities. It is currently being investigated in a phase I clinical trial. Mol Cancer Ther; 15(11); 2630-9. ©2016 AACR.

Distinct binding mode of multikinase inhibitor lenvatinib revealed by biochemical characterization.

Lenvatinib is an oral multikinase inhibitor that selectively inhibits vascular endothelial growth factor (VEGF) receptors 1 to 3 and other proangiogenic and oncogenic pathway-related receptor tyrosine kinases. To elucidate the origin of the potency of lenvatinib in VEGF receptor 2 (VEGFR2) inhibition, we conducted a kinetic interaction analysis of lenvatinib with VEGFR2 and X-ray analysis of the crystal structure of VEGFR2-lenvatinib complexes. Kinetic analysis revealed that lenvatinib had a rapid association rate constant and a relatively slow dissociation rate constant in complex with VEGFR2. Co-crystal structure analysis demonstrated that lenvatinib binds at its ATP mimetic quinoline moiety to the ATP binding site and to the neighboring region via a cyclopropane ring, adopting an Asp-Phe-Gly (DFG)-"in" conformation. These results suggest that lenvatinib is very distinct in its binding mode of interaction compared to the several approved VEGFR2 kinase inhibitors.

Multitargeting strategy using lenvatinib and golvatinib: maximizing anti-angiogenesis activity in a preclinical cancer model.

Almost all cancers show intrinsic and/or evasive resistance to vascular endothelial growth factor (VEGF) inhibitors by multiple mechanisms. Serum angiopoietin-2 (Ang2) level has been proposed as a potential biomarker of VEGF inhibitor response in several cancers. From these clinical observations, the Ang2 and Tie2 (its receptor) axis has been focused on as a promising target. Here, we show a novel strategy to circumvent the resistance by combining multi-tyrosine kinase inhibitors lenvatinib (VEGF receptor, fibroblast growth factor receptor, and RET inhibitor) and golvatinib (E7050; c-Met, Tie2, and EphB4 inhibitor). Tie2 identifies a highly pro-angiogenic macrophage subset, Tie2-expressing macrophages (TEM). Angi-Tie2 and EphB4-EphrinB2 signaling plays critical roles in pericyte-mediated vessel stabilization. In vitro analyses suggested that golvatinib combined with lenvatinib inhibited pericyte-mediated vessel stabilization and TEM differentiation. In thyroid and endometrial cancer models, golvatinib and lenvatinib inhibited pericyte network development and TEM infiltration, resulting in severe perfusion disorder and massive apoptosis. Body weight loss was tolerable, and no macroscopic change was observed. These preclinical studies suggest that modulation of the tumor microenvironment by a strategic and well-tolerated combination of multi-targeting tyrosine kinase inhibitors may sensitize cancer to VEGF inhibitors.