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.

A Feasibility Study of Capecitabine and Oxaliplatin for Patients with Stage II/III Colon Cancer -ACTOR Study

BACKGROUND/AIM

Past studies have suggested that adjuvant capecitabine and oxaliplatin (CAPOX) provides decreased tumor relapse and longer survival in patients with curatively resected colon cancer. We report the first evidence of the feasibility of adjuvant CAPOX in Japanese patients with early colon cancer.

PATIENTS AND METHODS

Eligible patients had histologically-confirmed stage II/III colon cancer and received curative resection. The primary endpoint was completion rate of treatment after 8 cycles of adjuvant CAPOX.

RESULTS

Thirty-six patients were enrolled in this study. The completion rate of CAPOX and oxaliplatin were 77.8% and 61.1%, respectively. The incidence of grade ≥3 adverse events was neutropenia (n=6), thrombocytopenia (n=3), nausea (n=5), hand-foot syndrome (n=1) and peripheral sensory neuropathy (n=1). Three-year disease-free survival for stage II patients and stage III patients were 100% and 79.3%, respectively.

CONCLUSION

Adjuvant CAPOX can be safely administered to Japanese patients with stage II/III colon cancer.

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.

Plasma biomarker analysis of ramucirumab in Japanese patients with advanced gastric cancer

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Background: Ramucirumab, anti-VEGFR2 receptor antibody, showed significantly improved survivals of gastric cancer in the second line with paclitaxel or single use. Recently we reported early elevation of plasma VEGF-A was associated with shorter survival as a preliminary result. We will report the results of final analysis. Methods: Patients with advanced gastric cancer who received ramucirumab combined with paclitaxel or single use were enrolled. Plasma samples were collected at pre-treatment and day 8 after administration. Nine kinds of plasma biomarker involved in angiogenesis, VEGF-A, C, D, PlGF, VEGFR1, 2, Angiopoietin 1, stromal cell derived factor-1α (SDF1α), and Neuropirin-1, were measured by means of ELISA. Patients were dichotomized by optimal cut-off value. Univariate and multivariate analysis were done by Cox proportion hazard model. Results: Forty-one patients were enrolled. Thirty-nine patients (95.1%) received ramucirumab with paclitaxel. Plasma VEGF-A, D, PlGF, and VEGFR2 levels were significantly increased one week after administration compared with baseline levels, while plasma VEGFR1 and NRP1levels were significantly decreased. Median PFS and OS were 5.6 (95% CI 4.66-6.54) and 9.8 (95% CI 5.41-14.19) months, respectively. In univariate analysis, higher baseline SDF1α and PlGF levels resulted in shorter OS with HR 2.71 95% CI 1.23-6.00, p =0.013 for SDF1α and HR 2.78 95% CI 1.16-6.65, p =0.022 for PlGF. Higher D8 VEGF-A was associated with shorter PFS with HR 2.77 95% CI 1.39-5.51, p =0.004. While higher D8 VEGF-D was associated with better PFS with HR 0.39 95% CI 0.20-0.77, p =0.007. In multivariate analysis, higher baseline SDF1α and PlGF were independent negative prognostic factor for OS with HR 2.45 95% CI 1.10-5.42, p =0.028 for SDF1α and HR 2.48 95% CI 1.03-5.96, p =0.043. With respect to PFS, higher D8 VEGF-A was also independent negative prognostic factor with HR 2.32 95% CI 1.13-4.77, p =0.022, while higher D8 VEGF-D was favorable predictor for PFS with HR 0.47 95% CI 0.23-0.96, p =0.038. Conclusions: Higher base line SDF1α and PlGF levels may be negative prognostic marker. While early VEGF-A and D elevation after ramucirumab administration may be predictive marker of ramucirumab.

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.

The clinical analysis of thromboembolism in esophagogastric cancer in Japan: A single institute experience

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Background: Although patients with esophagogastric cancer have a higher risk of thromboembolism (TE), the clinical characteristics of esophagogastric cancer patients with TE remain unclear. Methods: We conducted a retrospective study of who were treated for TE in our institution from January 2014 to August 2017. Results: During this period, 1538 esophaogastic cancer patients received anti cancer therapy. Of these 62 (4.0%) patients diagnosed as having TE during their clinical course. Background of these patitents were median age :64.5 (28-87), gender male/ female: 36 /26, 47 had gastric cancer, 12 esophageal cancer, and 2 gastroesophageal cancer. Performance Status were 0/1/2/3 = 21/24/13/4. Clinical stage were Ⅳ 32 (metastatic sites; lymph nodes 7, peritoneal dissemination 6, ovary 4, liver 1), recurrence 18, and other 12 respectively. 26 patients did not have medical history, 15 had hypertension, 4 had diabetes mellitus, and 4 had hyperlipidemia. Pathologically, adenocarcinoma 50, squamous carcinoma 10, and other 2. Among patients with gastric cancer, 6 (12.8%) showed Her2 overexpression. The median D-dimer levels was 4.81(0.42-17.25) μg/ml. The onset of TE was before starting chemotherapy in 8(12.9%), during receiving chemotherapy in 48(77.4%), and during washout period in 6. On patients who developed TE during receiving chemotherapy, the regimens of chemotherapy were S-1 16, weekly paclitaxel 10 (plus ramucirumab 3), SOX 7, FP 4, Irinotecan 3, SP 3, FOLFOX 3, XP+Trastuzumab3, and others 9. The types of venous thrombosis were deep vein thrombosis 33, pulmonary embolism 23, central venous catheter 7, internal jugular vein 5, subclavian vein 4, and others 5. Four patients suffered cerebral infarction due to thrombosis of the arterial system thrombosis. Initial anticoagulation treatment for TE were heparin 33, warfarin 13, edoxaban 12 and other 4. 29 patients (46.8%) had no symptom related TE. Conclusions: In our analysis, 12.9% patients had TE before starting treatment, we should pay attention to TE immediately after diagnosis of esophagogastric cancer. As 46.8% patients have no symptom related TE, it is important to develop of biomarkers for screening TE, likely D-dimer.

Multicenter phase I/II trial of BBI608 and pembrolizumab combination in patients with metastatic colorectal cancer (SCOOP Study): EPOC1503

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Background: The anti–programmed death 1 (PD-1) antibody, pembrolizumab provided an objective response rate (ORR) of 40% in patients (pts) with Mismatch Repair–Deficient (dMMR) or Microsatellite Instability–High (MSI-H) metastatic colorectal cancer (mCRC) vs 0% in pts with MMR-proficient/Microsatellite Stable (MSS) mCRC. The WNT/β-catenin signaling has been reported to prevent anti-tumor immunity and promote resistance of anti-PD-1/PD-L1 antibodies. This study investigates efficacy and safety of the combination of BBI608, which blocks phosphorylated STAT3 and downregulates WNT/β-catenin signaling, with pembrolizumab in pts with mCRC (both MSS and MSI-H). Here, we present the results of the phase I part. Methods: Phase I part was designed to determine the recommended phase II dose (RP2D) in a “3+3” cohort-based dose escalation design of BBI608 (240mg BID every day on level 1 and 480mg BID every day on level 2) with pembrolizumab (200mg/body q3w). We also conduct biomarker research using paired samples from repeated tumor biopsies and blood collections. Results: Five pts were enrolled in level 1, and 3 pts in level 2. All pts were MSS mCRC. Seven pts were included in the safety analyses. Two pts in level 1 were excluded from dose-limiting toxicity (DLT) evaluation because of disease progression during DLT evaluation period. No DLTs were observed at either level. Grade 3 or worse treatment-related adverse events (TRAEs) were not observed. Grade 1 or 2 TRAEs included diarrhea related to BBI608 (57%), hyperthyroidism (14%), hypothyroidism (14%), and fever (14%) without unexpected safety signals. One patient in level 2 showed a tumor shrinkage lasting more than 12 weeks for lung and lymph node metastases with remarkable decline of CEA level. Analysis of repeated tumor samples from this case demonstrated that CD8+ T-cells infiltration inside the tumor on treatment was observed by immunohistochemistry and flow-cytometry. Conclusions: BBI608 480mg BID with pembrolizumab was tolerable and determined as RP2D. This combination showed a hint of activity and might evoke immunity in MSS mCRC, which will be confirmed by ongoing phase II part. Clinical trial information: NCT02851004..

Association of malignant potential of BRAF mutant colorectal cancer with coexpression of PD-L1

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Background: PD-L1 is a member of the B7/CD28 family that regulates immune response, and also well known as targets for immune checkpoint inhibitor. On the other hand BRAF mutation (MT) is recognized as a strongly poor prognostic factor in colorectal cancer (CRC). Recently in addition to the RAS gene, a lot of new knowledge about some molecules playing an important role in the process of carcinogenesis or drug resistance, and emerging molecules as targets for new treatments have been reported. In this research, we aim to address the clinical significance of PD-L1 expression in colorectal carcinoma correlation between emerging molecules and differences through clinical stages in CRC using tissue array. Methods: Consecutive patients who underwent surgery in our hospital from June 2003 to March 2011 were enrolled in this study. Tissue array based profiling of emerging molecules was performed on archival samples using immunohistochemistry for BRAF, MLH1/MSH2/MSH6/PMS2, CDX2, HER2 and PD-L1. We analyzed PD-L1 expression and correlation with molecular profile, survival, clinicopathological findings and location of primary site. Results: A total of 1030 CRC from stage 0 to IV were analyzed. The expression rates of PD-L1 were 3.6% and increased significantly in BRAF MT, dMMR, lack of CDX-2, tumor grade3 (TG3), right sided colon of primary site (25%, 37.8%, 21.6%, 22.1%, 6.9%, respectively; P < 0.001). In the univariate analysis, lack of CDX2, BRAF MT and TG3 were identified as prognostic factors in whole population of this cohort. Furthermore the survival of BRAF MT and lack of CDX2 with co-expression of PD-L1 were extremely poor (median OS in stage IV; 2.6 months in both). In Particular the co-expression rates of PD-L1 in BRAF MT were increasing as the clinical stage progress regardless of dMMR. Conclusions: Our study comprehensively summarized the significance of PD-L1 expression associated with the recent emerging molecules and suggested that malignant potential of BRAF mutant CRC may be explained in part due to escape from immunity by co-expression of PD-L1. Immune checkpoint inhibitor could be a candidate of target of BRAF mutant CRC with PD-L1expression irrespective of MSI status.

Clinical outcomes of anti-EGFR antibody treatment for right-sided colon cancer patients without RAS, BRAF, and PIK3CA mutations in the later line

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Background: Several studies have reported that patients with right-sided colon cancers (RCC) have more unfavorable responses to anti-epidermal growth factor receptor (EGFR) antibody therapy than those with left-sided colon cancers (LCC). One of the causes is that RCC have more frequently genetic mutations such as RAS, BRAF, and PIK3CA than LCC. We investigated clinical outcomes of RCC patients treated with anti-EGFR antibody in the later line without these mutations. Methods: We reviewed 653 cases of colorectal cancer treated with anti-EGFR antibody from October 2009 to July 2017. There were 150 cases of RCC patients. Among them, 32 patients without KRAS status and 54 patients without enough genetic samples for gene re-analysis were excluded. We extracted 64 patients with status on RAS, BRAF, and PIK3CA , and finally enrolled 25 patients treated with anti-EGFR antibody plus irinotecan or anti-EGFR antibody alone in the later line. We analyzed the relationship of molecular status with clinical outcomes; overall response rate (RR), overall survival (OS) and progression-free survival (PFS) in this retrospective study. Results: Overall, there were 48% of cases with any mutations; among them 8.0% for KRAS, 4.0% for NRAS, 24.0% for BRAF and 4.0% for PIK3CA. Twenty percent of patients were treated as 2nd line therapy, while 72%, 16% treated as 3rd, 4th line therapy. RR of all cases, those whom without KRAS, RAS, RAS or BRAF, any mutations were 16.0%, 19.1%, 20.0%, 28.6%, 30.8%. The median OS and PFS in all wild-type patients were tended to be better than in those of all cases (OS; 14.9 vs. 11.6 months, hazard ratio = 0.70, p = 0.30, PFS; 8.17 vs. 5.37 months, hazard ratio = 0.67, p = 0.24). Conclusions: Even if primary tumors are in right-sided colon, in the enriched and selected patients anti-EGFR antibody therapy showed enough antitumor activity. Anti-EGFR antibody for RCC cases without using it at the front line is an effective option in the later line.

Chemoradiation for the treatment of locoregional squamous cell carcinoma of the anal canal: A single center retrospective analysis in Japan

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Background: Squamous cell carcinoma of the anal canal (SCCA) is a rare malignancy. In western countries, chemoradiotherapy (CRT) has become the standard treatment for locoregional SCCA according to National Comprehensive Cancer Network guidelines. But only some small amount case reports have been found about CRT for SCCA in Japan. We retrospectively evaluated the results of CRT for SCCA at a single center in Japan. Methods: We had treated 33 patients with the concurrent CRT at the Cancer Institute Hospital between 2007 and 2017. RT consisted of 45.0 to 59.4 Gy given in 5 to 7 weeks, with a daily dose of 1.8 Gy. Chemotherapy was given during RT: 1000mg/m2 daily fluorouracil (FU) as a continuous infusion on day 1 to 4 and 29 to 32, and a single dose of mitomycin C (MMC) 10mg/m2 administered on day 1 and 29. Data on relapse and deaths were obtained until August 2017. Results: Of 33 patients who were treated with CRT, the median age was 59 (range 35-82) years. Male to female sex ratio was 1:4.5. Patients who had Eastern Cooperative Oncology Group Performance Status (ECOG PS) 0 were 88% and patients who had ECOG PS 1 were 12%. The clinical stages before CRT were cStage I in 9 (27%), II in 4 (12%), IIIA in 6 (18%) and IIIB in 14 (42%). Although clinical complete response (CR) was observed in 29 patients of 33 (88%), 5 patients of 29 recurred. No patients recurred in cStage I and II. SCCA remained or recurred in 2 patients of 6 in cStage IIIA and 7 patients of 14 in cStage IIIB. 3-year disease free survival (DFS) was 71.3% (95%CI: 52.0-84.0%), and 3-year overall survival was 81.8% (95%CI: 55.1-92.8%). Conclusions: CRT for SCCA resulted in clinically meaningful impact on DFS and OS in our hospital. Therefore, CRT may be the standard of treatment also in Japan.

Identification of biomarkers for TAS-102 efficacy in metastatic colorectal cancer patients based on preclinical analysis and clinical validation

669

Background: Trifluridine (FTD) incorporation into DNA is the main anti-tumor mechanism of action of TAS-102. We performed preclinical analysis and translational validation study to identify the candidate cytokines for TAS-102 efficacy in metastatic colorectal cancer (mCRC) patients (pts). Methods: As a first preclinical process, we selected candidate cytokines according to our transcriptomic and cell biological analysis. We then validated predictive value of the cytokines in mCRC pts receiving TAS-102 (discovery) and regorafenib (control). Blood samples were obtained at baseline (BL), before second cycle (2nd) and progressive disease (PD), and cytokine levels were measured using ELISA. The change patterns were defined as ‘increased’ or ‘decreased’ from BL. Results: 93 pts were included in this study: 67 received TAS-102 and 26 received regorafenib. Preclinical cDNA microarray analysis with colon cancer cell lines demonstrated marked changes in the RNA expression of interleukin-8, VEGF-A and epiregulin (EREG) after FTD treatment. Particularly, in preclinical model, EREG secretion was highly measured after FTD treatment in FTD-sensitive cells, while not in FTD-resistant cells. In the discovery cohort, increased EREG levels at 2nd showed trend toward longer PFS and OS than decreased changes (2.6 vs 2.3 mos, P= 0.096; 10.8 vs 6.2 mos, P= 0.091). Meanwhile, decreased EREG levels at PD were marginally associated with longer PFS and significantly with longer OS than increased (4.0 vs 2.3 mos, P= 0.130; 9.8 vs. 6.2 mos, P= 0.016). Combined analysis of EREG changes showed that pts with either increased at 2nd or decreased at PD had significantly longer PFS and OS compared to those with both decreased at 2nd and increased at PD (3.0 vs 2.0 mos, HR: 0.47, 95%CI: 0.24-0.93, P= 0.031; 10.8 vs 5.3 mos, HR: 0.30, 95%CI: 0.14-0.61, P= 0.001). The findings were confirmed in the multivariate analysis for OS (HR: 0.311, 95%CI: 0.15-0.66, P= 0.002), and no significant differences were observed in the control cohort. Conclusions: Our preclinical data-based translational validation study suggests that serum EREG levels may predict clinical outcome in mCRC pts receiving TAS-102.

Clinical impact of diverting ileostomy on the dose intensity of adjuvant chemotherapy for colorectal cancer

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Background: CAPOX as adjuvant chemotherapy is a standard care option for stage III and high risk stage II colorectal cancer(CRC). And then chemotherapy induced diarrhea (CID) is known as one of the dose-limiting toxicities for CAPOX. Although diverting ileostomy is useful for preventing serious complications of high risk anastomosis, it is well recognized that high ileostomy output is hard to manage. Furthermore, the effect of diverting ileostomy on CID of adjuvant chemotherapy is unclear. In this study, we addressed the clinical impact of diverting ileostomy on the dose intensity of adjuvant chemotherapy for CRC. Methods: Patients who diagnosed with stage III colon cancer and stage II or III rectal cancer after curative surgery and received CAPOX as adjuvant chemotherapy during 2011- 2014 were reviewed retrospectively. We investigated the relationship between diverting ileostomy and dose intensity, toxicities and disease-free survival (DFS). Results: 112 patients (median age 60 years, 52% male, 69% colon cancer, 63% stage III, median follow-up 47 months) were enrolled in this study. Of 112 patients, 100 patients were received chemotherapy without ileostomy (non-ileostomy group: NIG) and 12 patients were received chemotherapy with ileostomy (ileostomy group: IG). 112 Patients received 870 chemotherapy cycles. All treatment related grade 3/4 adverse events were documented in 39% of patients in NIG and 33% of patients in IG (P = 0.77). Grade 3/4 of CID occurred in 8% of patients in NIG and 8% of patients in IG (P = 1). Grade 3/4 of neutropenia were recognized in 21% of patients in NIG and 17% of patients in IG (P = 1). Average relative dose intensity (RDI) in NIG were 75.7% and 85.8% for capecitabine and oxaliplatin, respectively. Average RDI of capecitabine and oxaliplatin in IG were 76.1% and 82.7%, respectively. Significant difference of RDI of capecitabine and oxaliplatin were not shown in comparison between NIG and IG (P = 0.93, P = 0.63). The 3-year DFS rate was 85.0% in NIG and 75.0% in IG. The HR for DFS for NIG compared to IG was 1.709 (95% CI, 0.49 to 5.95; P = 0.40). Conclusions: The presence of diverting ileostomy does not affect RDI of CAPOX as adjuvant chemotherapy.

Plasma biomarker dynamics following ramucirumab treatment and survival analysis after ramucirumab treatment failure in patients with advanced gastric cancer

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Background: Ramucirumab (RAM) showed significantly improved survivals of gastric cancer in the second line with paclitaxel or single use. It is known that RAM causes pharmacodynamic changes of plasma VEGF-A family levels during treatment. However, its clinical significance is still unclear. The aim of this study is to reveal the changes of plasma biomarker levels until disease progression, and to examine associations between plasma biomarker levels at disease progression and survival after RAM treatment failure. Methods: Plasma samples were collected at three points: base line, day 8, and disease progression. Nine kinds of plasma biomarker related to angiogenesis: VEGF-A, C, D, PlGF, sVEGFR-1, 2, Neuropilin-1 (NRP1), Angiopietin-1, and SDF-1α, were measured by means of ELISA. The dynamics of plasma biomarkers were compared using the ANOVA. Patients were dichotomized by optimal cut-off value in each biomarker. Survival after RAM treatment failure was estimated by Kaplan-Maier methods and compared by log-rank test. Results: Plasma samples were collected from 21 patients. Median age was 67 y.o and female was dominant (57%). Plasma VEGF-A and PlGF levels sharply increased at day 8 and these higher plasma levels were sustained until disease progression: the median VEGF-A and PlGF levels at baseline, day 8, and disease progression were 20.2, 350.2, and 596.7 pg/ml for VEGF-A (p<0.001) and 10.5, 223.4, and 261.1 pg/ml for PlGF (p<0.001), respectively. Conversely, plasma NRP1 levels consistently decreased during treatment course: the median NRP1 levels at baseline, day 8, and disease progression were 444.3, 309.2, and 230.9 mg/ml (p=0.001). The median survival after disease progression was 3.1 months (95%CI 2.5-3.7). Patients with higher VEGF-A and NRP1 levels showed shorter survival with 4.5 vs. 0.9 months (HR 3.15 95%CI 1.6-6.4 p<0.001) for VEGF-A and 8.8 vs. 2.6 months (HR 2.92 95% CI 1.4-6.3 p=0.002) for NRP1. Conclusions: Our data suggest that not only a clue of mechanism of acquired resistance of RAM but necessity of new treatment strategy after RAM treatment failure. Further understanding of molecular correlates and clinical validation are warranted.

Clinical significance of morphologic response and tumor shrinkage as predictive factors of Capeox+bevacizumab in 1st line treatment of metastatic colorectal cancer

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Background: Capeox + bevacizumab (BV) is one of the standard treatment for metastatic colorectal cancer (mCRC) and well known to sometimes cause morphologic response (MR). However, it is not well known the predictive value of MR in palliative chemotherapy of Capeox + BV as 1st line. The aim of this study was to investigate the clinical significance of MR and tumor shrinkage as predictive factors of Capeox+BV in 1st line treatment of mCRC. Methods: A total of 159 patients with CLM were selected from 316 mCRC patients treated with Capeox+BV as 1st line chemotherapy from February 2006 to August 2016. Among these patients, 92 patients were enrolled in the this study, who satisfied following criteria; (1) tumor responce was assesed by enhanced computed tomography (CT) images every 2-3 months, and (2) dose intensity of BV at first 4 courses were above 80%. Tumor response of RECIST1.1 and MR were evaluated by 2 radiologists. They classified them as optimal, incomplete or no morphologic response according to the morphologic criteria. Results: An optimal morphologic response (OR) was observed in 34% of all patients. The median progression-free survival (mPFS) was 9.3 months in this cohort, 13.5 months in patients with OR and 11.6 months in those with incomplete/no morphologic response. And the median overall survival (mOS) was 19.5 months, 30.3 months and 23.8 months, respectively. There were no statistical significance between OR and the other, irrespective of mPFS and mOS. On the other hand, mPFS was 14.6 months in responder as CR or PR of RECIST and 8.6 months in non responder as SD or PD (p < 0.0001). Furthermore, mOS, 31.9 months and 18.5 months, respectively (p < 0.0001). Besides in 17 patients fulfilled both responder of RECIST and OR, the mOS reached 45.4 months, which was remarkably longer compared to the other groups ( < 0.0001). Conclusions: Among mCRC patients with CLM treated with Capeox+BV as the 1st line, the response of RECIST well reflected the therapeutic effect. On the other hand, MR solely was not a predictor of therapeutic effect in this study. However, both responder of RECIST and OR may be on-treatment predictors to identify excellent prognostic group.

Serum VEGF-A and CCL5 levels as candidate biomarkers for efficacy and toxicity of regorafenib in patients with metastatic colorectal cancer

Regorafenib is an oral multi-kinase inhibitor used as salvage therapy for metastatic colorectal cancer (mCRC). We tested whether serum cytokine levels are associated with clinical outcome in the mCRC patients receiving regorafenib. Serum samples were collected before treatment start, day 21, and progressive disease, and eleven angiogenic and inflammatory cytokine serum levels were examined. Fifty-four patients of a total of 62 enrolled patients were eligible for the analyses. The chemokine ligand 5 (CCL5) levels ≤ cut-off value (59959 pg/ml) at baseline was associated with relative tumor shrinkage (P = 0.021), better progression-free survival (PFS) (P = 0.036) and overall survival (OS) (P = 0.019). Vascular endothelial growth factor A (VEGF-A) levels showing a decrease on day 21 were significantly associated with a better PFS (P = 0.021). CCL5 levels ≤ cut-off was associated with any grade hand-foot skin reaction (HFSR) (P = 0.025) and thrombocytopenia (P = 0.013). Low chemokine ligand 2 levels at baseline were associated with grade 2 ≤ HFSR. High angiopoietin-2 and basic fibroblast growth factor (bFGF) levels at baseline were associated with grade 3 ≤ total bilirubin increase and transaminases increase, respectively. Low bFGF levels at baseline were associated with grade 3 ≤ hypertension. No correlation with severe events was observed. Baseline serum CCL5 levels and decrease of the serum VEGF-A levels may serve as potential predictive markers for survival or treatment-specific toxicities in mCRC patients receiving regorafenib.

Clinical significance of BRAF non-V600E mutations on the therapeutic effects of anti-EGFR monoclonal antibody treatment in patients with pretreated metastatic colorectal cancer: the Biomarker Research for anti-EGFR monoclonal Antibodies by Comprehensive Cancer genomics (BREAC) study

Background:

Patients with BRAF^V600E-mutated metastatic colorectal cancer (mCRC) have a poorer prognosis as well as resistance to anti-EGFR antibodies. However, it is unclear whether BRAF mutations other than BRAF^V600E (BRAF^non-V600E mutations) contribute to anti-EGFR antibody resistance.

Methods:

This study was composed of exploratory and inference cohorts. Candidate biomarkers identified by whole exome sequencing from super-responders and nonresponders in the exploratory cohort were validated by targeted resequencing for patients who received anti-EGFR antibody in the inference cohort.

Results:

In the exploratory cohort, 31 candidate biomarkers, including KRAS/NRAS/BRAF mutations, were identified. Targeted resequencing of 150 patients in the inference cohort revealed 40 patients with RAS (26.7%), 9 patients with BRAF^V600E (6.0%), and 7 patients with BRAF^non-V600E mutations (4.7%), respectively. The response rates in RAS, BRAF^V600E, and BRAF^non-V600E were lower than those in RAS/BRAF wild-type (2.5%, 0%, and 0% vs 31.9%). The median PFS in BRAF^non-V600E mutations was 2.4 months, similar to that in RAS or BRAF^V600E mutations (2.1 and 1.6 months) but significantly worse than that in wild-type RAS/BRAF (5.9 months).

Conclusions:

Although BRAF^non-V600E mutations identified were a rare and unestablished molecular subtype, certain BRAF^non-V600E mutations might contribute to a lesser benefit of anti-EGFR monoclonal antibody treatment.

Abstract 2712: Relationship between CLDN18-ARHGAP fusion gene and clinicopathological features of gastric cancer in young adult

Introduction: Gastric cancer (GC) in young adults comprises a small part of this disease population having the distinctive clinicopathological features, such as diffusive tumor growth and peritoneal dissemination. Genetic alterations underlying these features and the development of cancer in early ages remain unclear. Comprehensive molecular analyses by TCGA have suggested 4 molecular subtyping of GC and revealed enrichment of CLDN18-ARHGAP fusion gene in Genomically stable (GS) type which mainly included diffuse type. In this study, we examined the relationship between CLDN18-ARHGAP and clinicopathological features of GC affecting young adults.

Method: Patients (pts) diagnosed at the age younger than 40 years-old were defined as the GC in young adults, and underwent surgery at our institute between Jan 2006 and Dec 2015 were enrolled to this study. Tissue microarrays were prepared from formalin-fixed and paraffin-embedded surgical specimen. DNA probes for CLDN18, ARHGAP-26 and -6 were created using bacterial artificial chromosomes and fusion genes were detected by a FISH method.

Results: Out of 155 surgical specimens available for analysis, we found CLDN18-ARHGAP fusion gene in 21 pts (13.5%). Among these, 19 cases were CLDN18-ARHGAP26 fusion and the others were CLDN18-ARHGAP6. Cancers with CLDN18-ARHGAP fusion genes were all diagnosed as diffuse type and included more large-sized, multiple lymph node metastases and advanced stages tumors (table 1). The proportion of detected fusion genes in this study was almost equivalent to that of GS type in TCGA cohort. Analysis of variations of breakpoint is planned to confirm by RT-PCR and sequencing. Additionally, we are going to study the association of CLDN18-ARHGAP with RHOA or CDH-1.

Conclusion: CLDN18-ARHGAP fusion gene might account for the characteristic of a part of diffuse type GC. Further comprehensive molecular analysis comparing to general GC population is warranted.

Patient demographicspositive (n=21)negative (n=134)p-valueAge0.646&lt;30 / 30-392 / 199 / 125Sex0.482man / woman8 / 1365 / 69Tumor location0.507Upper /Middle /Lower4 / 10 / 743/ 53 / 38Tumor size (mm)75.664.70.117≤80 / 80&lt;9 / 1234 / 100Borrmann0.648Type2 / 3 / 4 / others0 / 8 / 3 / 1010 / 38 / 20 / 62LaurenNSintestinal / diffuse / mixed0 / 21 / 05 / 124 / 5T (TNM)0.479T1 / T2 / T3 / T46 / 1 / 4 / 1050 / 18 / 18 / 48N (TNM)0.044N1 / N2 / N36 / 2 / 2 / 1171 / 12 / 20 / 31Stage (TNM)0.032I / 2 / 3 / 47 / 1 / 5 / 857 / 28 / 31 / 18

Citation Format: Izuma Nakayama, Eiji Shinozaki, Seiji Sakata, Noriko Yamamoto, Satoko Baba, Kensei Yamaguchi, Shunji Takahashi, Kengo Takeuchi, Tetsuo Noda. Relationship between CLDN18-ARHGAP fusion gene and clinicopathological features of gastric cancer in young adult [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2712. doi:10.1158/1538-7445.AM2017-2712

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.

Multicenter phase I/II trial of BBI608 and pembrolizumab combination in patients with metastatic colorectal cancer (SCOOP Study): EPOC1503

TPS3623

Background: Immune checkpoint inhibitor (ICI) was reported to show durable responses in patients with MSI-H (Microsatellite Instability-High) metastatic colorectal cancer (mCRC). On the other hand, for patients with MSS (Microsatellite Stable) mCRC, ICI monotherapy achieved no response. Recently, WNT/β-catenin signaling has been reported to be involved in the elimination of tumor-infiltrating lymphocytes and the resistance of anti-PD-L1 antibodies. CRC is representative cancer with WNT/β-catenin pathway activation. Furthermore, STAT3 has also been reported to be a key driver of this immune evasion. Considering these rationales, the blocking of these signaling pathways with ICI may enhance antitumor immune response. Therefore, we initiated phase I/II study to assess efficacy and safety for the combination of BBI608, which blocks STAT3 and WNT/β-catenin signaling, with pembrolizumab in patients with mCRC. Methods: The eligibility criteria were patients with gastrointestinal cancer not responded to or intolerant of standard chemotherapies (SOC) for phase I part, and MSS mCRC refractory or intolerant to fluoropyrimidine, irinotecan, oxaliplatin, and anti-EGFR antibody (if wild-type RAS) for Cohort B in phase II part. For Cohort A, MSI-H mCRC refractory or intolerant to the SOC, irrespective of anti-EGFR antibody are investigated. Phase I part was designed to determine the recommended phase II dose in a “3+3” cohort-based dose escalation design of BBI608 (240mg BID every day on level 1 and 480mg BID every day on level 2) with pembrolizumab (200mg/body q3w). Primary endpoint of the phase II part is Immune-related objective response rate (irORR) determined by their Response Evaluation Criteria In Solid Tumors (irRECIST). A null hypothesis and alternative hypothesis for cohort B are irORR = 5% and 20%, respectively. Required sample size for Cohort B was 40 with a one-sided alpha of 5% and power of 90%. Required sample size for Cohort A (10 patients) was determined in an exploratory manner. We also investigate biomarker study using paired samples of both tumor biopsy and blood. The enrollment to phase I part began in November 2016. Clinical trial information: NCT02851004. Clinical trial information: NCT02851004.

A phase II study of panitumumab with FOLFOX or FOLFIRI as first-line chemotherapy for KRAS-wild type metastatic colorectal cancer: The PaFF-J study

722

Background: For the patients with unresectable metastatic colorectal cancer (mCRC), response to the1st line chemotherapy has strong impact on their prognosis. Shrinkage of tumors may result in conversion to surgical resection and, concurrently, improved their survival. We conducted a multicenter phase II trial to investigate the efficacy and safety of panitumumab (Pmab) with chemotherapy as the 1st line treatment in Japanese patients with mCRC. Methods: Patients with no prior chemotherapy for unresectable, KRAS wild type mCRC, 20-80 years, and PS 0-1 were arbitrarily received either FOLFOX + Pmab or FOLFIRI + Pmab. Patients were evaluated every 8 weeks until progression. The primary endpoint was overall response rate (ORR), the secondary endpoints were progression-free survival (PFS), overall survival (OS), disease control rate (DCR), R0 resection rate, and safety. Results: A total of 162 patients (140 with FOLFOX + Pmab and 22 with FOLFIRI + Pmab) were analyzed. Median follow-up was 28.2 months, median age at enrollment was 64.5 years, and 17.9% of the patients was recurrent disease. Number of target organ was 1 in 35.2%, 2 in 40.7%, and ≥ 3 in 24.1% of the subjects. Median administered cycle was 7, and median treatment duration was 16 weeks. ORR was 51.2% (95%CI: 43.3-59.2), and DCR was 82.1% (95%CI: 75.3-87.7). ≥ 30% tumor shrinkage (PR-in) was observed in 115 patients (71.0%). Median time to PR-in and maximum shrinkage was 10 and 16 weeks, respectively. Surgical resection was done in 66 patients (40.7%), of which R0 was in 43 patients; R0 resection rate was 26.5% (95%CI: 19.9-34.0). Median PFS and OS was 9.2 (95%CI: 7.2-11.4) and 33.8 months (95%CI: 29.4-43.1), respectively. ≥ Grade 3 adverse events with > 5% incidence were neutropenia (31.8%), stomatitis (10.5%), rash acneiform (9.9%), paronychia (9.3%), anorexia (8.6%), and diarrhea (6.2%). Conclusions: In our study, OS was favorable with high R0 resection rate, whereas ORR, DCR, PFS and toxicities were similar to those in previously reported studies. Because the maximum tumor shrinkage was observed around 16 weeks, optimal timing for considering conversion surgery might be 16 weeks from the start of treatment. Clinical trial information: UMIN000004991.