Hokkaido Gastrointestinal Cancer Study Group Research Articles

Study protocol for HGCSG1801: A multicenter, prospective, phase II trial of second-line FOLFIRI plus aflibercept in patients with metastatic colorectal cancer refractory to anti-EGFR antibodies.

The first-line chemotherapy for patients with RAS and BRAF wild-type metastatic colorectal cancer (mCRC) commonly involves cytotoxic regimens, such as FOLFOX and FOLFIRI, combined with epidermal growth factor receptor (EGFR) antibodies. When progression occurs following anti-EGFR antibody-combined chemotherapy, anti-angiogenic inhibitors can be used as second-line treatment. Although randomized controlled trials have shown that anti-angiogenic inhibitors [bevacizumab, ramucirumab, and aflibercept (AFL)] carry survival benefit when combined with FOLFIRI as second-line chemotherapy, such trials did not provide data on patients with mCRC refractory to anti-EGFR antibody-combined chemotherapy. Therefore, our group planned a multicenter, nonrandomized, single-arm, prospective, phase II study to investigate the safety and efficacy of FOLFIRI plus AFL as a second-line chemotherapy for patients with mCRC refractory to oxaliplatin-based chemotherapy combined with anti-EGFR antibodies. FOLFIRI (irinotecan 180 mg/m2, l-leucovorin 200 mg/m2, bolus 5-FU 400 mg/m2, and infusional 5-FU 2400 mg/m2/46h) and AFL (4 mg/kg) will be administered every 2 weeks until progression or unacceptable toxicities occur. The primary endpoint will be the 6-month progression-free survival (PFS) rate, whereas the secondary endpoints will include overall survival, PFS, response rate, disease control rate, adverse events, and relative dose intensity for each drug. A sample size of 41 participants will be required. This study will be sponsored by the Non-Profit Organization Hokkaido Gastrointestinal Cancer Study Group and will be supported by a grant from Sanofi. There is only an observational study reporting data on FOLFIRI plus AFL for patients with mCRC who previously received anti-EGFR antibodies; therefore, a prospective clinical trial is needed. This study will prospectively evaluate the efficacy and safety of FOLFIRI plus AFL in patients with mCRC who are resistant to anti-EGFR antibodies and have limited data. Moreover, this study will reveal predictive biomarkers for AFL-based chemotherapy. Japan Registry of Clinical Trials, jRCTs011190006. Registered 19 November, 2019, https://jrct.niph.go.jp/latest-detail/jRCTs011190006.

94P - NORTH/HGCSG1003: North Japan multicenter phase II study of oxaliplatin-containing regimen as adjuvant chemotherapy for stage III colon cancer: Final analysis

BackgroundFOLFOX and CAPOX are standard adjuvant chemotherapy for resected stage III colon cancer. MOSAIC and XELOXA trials were performed outside of Japan, thus, we conducted a phase II study (NORTH/HGCSG1003) to assess the efficacy and safety of FOLFOX as adjuvant chemotherapy for Japanese patients(pts) with resected stage III colon cancer (UMIN ID: 000004590). MethodsThis phase II study enrolled patients with resected stage III colon cancer. Patients received 12 cycles of FOLFOX4 or mFOLFOX6. Sample size was determined to be 243 pts. Primary endpoint was disease-free survival (DFS). We assumed an expected 3-year DFS rate of 81.2% in this study. Secondary endpoints included overall survival (OS) and safety. In this meeting, we present for the 5-year OS rate. ResultsFrom Sep 2010 to Mar 2013, 273 pts were enrolled at 28 institutions. Full analysis included 265 patients who received FOLFOX. Patients characteristics were as follows: median age; 65(33-84), Male/female; 131/134, PS 0/1; 258/7, stage IIIA/IIIB/IIIC; 37/197/31, colon/rectosigmoid: 214/51. The most common grade 3-4 adverse events were neutrophil count decreased (48.1%), peripheral sensory neuropathy (6.4%), platelet count decreased (2.3%), and allergic reaction (1.5%). The median number of cycles of FOLFOX was 12, and the completion treatment rate was 80.4%. There was no treatment-related death. The 3-year/5-year DFS rate was 76.0%(95%C.I. 70.3- 80.7)/70.6%(95%C.I. 64.7-75.7). The 3-year/5-year 0S rate was 95.8%(95%C.I. 92.5- 97.7)/88.1%(95%C.I. 83.5-91.5). ConclusionsIn Japanese patients with resected stage III colon cancer, FOLFOX is a well-tolerable regimen as adjuvant chemotherapy. In this trial, the 3-year DFS rate of primary endpoint was not meet the expectation. However, the 3-year DFS and 5-year OS rate in this trial were similar to several pivotal trials. Clinical trial identificationUMIN ID: 000004590. Legal entity responsible for the studyNon-Political Organization: Hokkaido Gastrointestinal Cancer Study Group. FundingNon-Political Organization: Hokkaido Gastrointestinal Cancer Study Group. DisclosureS. Yuki: Honoraria (self): Yakult Honsha Co. Ltd. All other authors have declared no conflicts of interest.

P-176 - Multicenter phase 2 trial of weekly 5-FU plus l-LV regimen as salvage line chemotherapy for oral fluorouracil-resistant advanced gastric cancer (HGCSG1502)

Abstract Background 5-Fluorouracil (5-FU) is a key drug in treatment of unresectable advanced gastric cancer (AGC). It is known that intravenous 5-FU and oral fluorouracil have different mechanism as anti-cancer drugs, however, a clinical benefit of intravenous 5-FU after using oral fluorouracil is not clear. Therefore, we planned a prospective study to assess the efficacy and safety of weekly intravenous 5-FU and l-leucovorin(l-LV) in Japanese patients with AGC which was resistant for oral fluorouracil, taxane, and platinum. This encore abstract was previously reported at the ESMO 21st World Congress on Gastrointestinal Cancer 2019; the abstract number was P-176. Methods This regimen consisted of l-LV 250mg/m2/2h iv and 5-FU 600mg/m2 iv once a week for 6 weeks followed by 2-week rest period, within an 8-week cycle. The primary endpoint was the progression free survival (PFS) rate at 8 weeks. Results Among the 29 enrolled patients, PFS rate at 8 weeks was 55.2% (95% CI 35.6% to 71.0%), which was higher than 47.5% which is the expected value of the hypothesis, and the lower limit of 95% CI is significantly higher than the threshold which is 23.1%. Grade 3 to 4 hematological adverse events (AE) were as follows; anemia 20.7%, neutropenia 3.4%, and platelet count decreased 3.4%. Grade 3 to 4 non-hematological AE were observed as follows; anorexia 20.7%, fatigue 13.8%, and diarrhea 3.4%. Conclusions The intravenous 5-FU and l-LV regimen is feasible and could be promising as the salvage line treatment in patients with AGC even if that is resistant for oral fluorouracil, taxane and platinum. Legal entity responsible for the study The Helsinki Ethical Principles (revised in Oct, 2013) and the Ethical Guidelines for Medical and Health Research involving in Human Subjects in 2014. Funding Hokkaido Gastrointestinal Cancer Study Group. Disclosure All authors have declared no conflicts of interest.

196P - HGCSG1403: Phase I trial of oxaliplatin/irinotecan/S-1 (OX-IRIS) as first-line chemotherapy for unresectable pancreatic cancer

Background: In recent years, FOLFIRINOX has become one of the primary standard treatment for unresectable pancreatic cancer (PC) with distant metastasis. OX-IRIS is the combination therapy of oxaliplatin (L-OHP), irinotecan (IRI) and S-1. It is the useful treatment to dispense with a continuous infusion of 5FU by administering S-1 orally. For establishing OX-IRIS therapy as a new standard treatment, we planned this study. Methods: Chemotherapy-naïve patients with unresectable PC were included. L-OHP and IRI were administered on day 1 and 15, and S-1 was taken twice a day in day 1-14, and 14 days were rest for 1 cycle. This study used a standard 3 plus 3 design, and we evaluated safety and tolerability in 3 to 6 cases of each levels. It was assumed until 1 cycle completion for the evaluation period of dose limiting toxicity (DLT). Maximum tolerated dose (MTD) was defined as the highest dose beyond a more of one-third within DLT evaluation period. The primary endpoint was the frequency of DLT and MTD. Secondary endpoints were the frequency of adverse events, response rate, progression-free survival (PFS) and overall survival (OS). Results: Between January 2016 and August 2017, 13 cases were enrolled. The patients’ backgrounds were median age 62 years old, man/woman; 9/4, the primary tumor sites head/body and tail; 8/5, ECOG PS 0/1; 7/6, UR-LA/UR-M; 4/9. Two of five patients enrolled in level 0 (L-OHP: 85 mg/m2, IRI: 100 mg/m2, S-1: 80 mg/m2) had DLT. In two of eight patients enrolled in level -1 (L-OHP: 65 mg/m2, IRI: 100 mg/m2, S-1: 80 mg/m2), DLT was impossible to evaluate because the treatment of 1 cycle was not accomplished. And one of remaining six cases had DLT. At level 0, 100% of cases had anemia and fatigue, 80% had anorexia, diarrhea, peripheral sensory neuropathy, 60% had platelet count decrease. At level -1, 100% of cases had anemia, 75% had nausea and fatigue, 63% had anorexia. Response rate was 10% and disease control rate was 70% in ten cases with the evaluable lesion. Median PFS was 4.1 months. Conclusions: In this study, MTD was estimated to be level 0, and determined that recommended dose (RD) was level -1 in the planned future study. We are going to evaluate efficacy and the safety in a phase II study. Clinical trial identification: UMIN000017002 - 2015/04/01. Legal entity responsible for the study: Non-profit Organization: Hokkaido Gastrointestinal Cancer Study Group. Funding: Non-profit Organization: Hokkaido Gastrointestinal Cancer Study Group. Disclosure: S. Yuki: Honoraria: Yakult Honsha, Taiho Pharmaceutical. Y. Komatsu: Honoraria: Taiho Pharmaceutical; Donation: Taiho Pharmaceutical, Yakult Honsha; Research fund: Taiho Pharmaceutical. All other authors have declared no conflicts of interest.

440P - A multicenter prospective study on the efficacy and safety of denosumab in gastrointestinal cancer patients receiving short-term periodic steroid premedication for prevention of chemotherapy-induced nausea and vomiting (ESPRESSO-02/HGCSG1602)

Background: We previously reported that short-term periodic premedication of glucocorticoids (GCs) used with chemotherapy for gastrointestinal cancer (GIC) caused the reduction of bone mineral densities (BMD) (ESPRESSO-01 study; Oncologist 2017). We conducted this study to evaluate the efficacy and safety of denosumab for prevention of chemotherapy-induced BMD decrease. Methods: The eligibility criteria were as the follows: 1) Histologically confirmed GIC, including esophageal, gastric, pancreatic, and biliary cancer; 2) a schedule of periodical intravenous steroid administration as premedication that was weekly, biweekly, or triweekly, and in which >4-week steroid-free intervals were not allowed; 3) high-risk patient with steroid-induced secondary osteoporosis; 4) no prior treatment for osteoporosis. The dose of denosumab is 60mg administered as a single subcutaneous injection within a week before the induction of chemotherapy. All participants should receive adequate calcium and vitamin D supplementation. The primary endpoint was to investigate the BMD change on lumbar spine between baseline and 16 weeks after induction of chemotherapy. Results: From April 2017 to Feb 2018, 49 cases were enrolled. Two patients did not meet the inclusion criteria. One patient died before treatment and one patient refused just after enrollment. One case was not measured for BMD at baseline and three patients were not measured for BMD at 16 weeks, due to patient refusal, discontinuation of treatment, death and so on (41 cases were the full analysis set). In 30 cases (73.2% of FAS), the levels of BMD at 16w were significantly increased compared with baseline and the average percent change of BMD of lumbar spine was 2.767% (n = 41, 95% CI: 1.308% to 4.225%, p < 0.0001). No one suffered any bone fracture in FAS population. Conclusions: We found that denosumab administration could prevent the reduction of BMD and bone fracture. Clinical trial identification: UMIN000023855. Legal entity responsible for the study: Hokkaido Gastrointestinal Cancer Study Group (HGCSG). Funding: Has not received any funding. Disclosure: M. Nakamura: Honoraria: AstraZeneca, Bayer Yakuhin, Chugai, Daiichi Sankyo, Merck Serono, Nippon Boehringer Ingelheim, Taiho, Takeda. Y. Tsuji: Honoraria: Merck Serono, Eli Lilly Japan, Chugai, Taiho, Ono, Daiichi Sankyo, Yakult Honsha, Eisai, Medicon. Y. Komatsu: Honoraria: Bayer Yakuhin, Chugai, Taiho, Takeda, Eli Lilly Japan; Research expenses: Ono, MSD, Eli Lilly Japan, Taiho, Daiichi Sankyo, Chugai. All other authors have declared no conflicts of interest.

Study protocol of HGCSG1404 SNOW study: a phase I/II trial of combined chemotherapy of S-1, nab-paclitaxel and oxaliplatin administered biweekly to patients with advanced gastric cancer

BackgroundIn Japan, S-1 plus cisplatin (SP) regimen has become a standard therapy for patients with advanced gastric cancer. Moreover, the S-1 plus oxaliplatin regimen is now a standard treatment.Nab-paclitaxel was developed for chemotherapy of gastric cancer in Japanese clinical practice. Nab-paclitaxel, created with albumin-bound paclitaxel particles, has high transferability to tumour tissues and does not cause hypersensitivity reactions because of a different chemical composition compared with docetaxel and paclitaxel.A combination of S-1, nab-paclitaxel and oxaliplatin (which we named ‘SNOW regimen’) can be a promising triplet therapy for advanced gastric cancer. Although we have to pay attention to chemotherapy-induced neuropathy, we aim to investigate the recommended dose of this regimen in a phase I study. Furthermore, we will investigate its efficacy and toxicity in a phase II study.MethodsThe phase I study is a dose-escalation study using a standard 3 plus 3 design, followed by expansion cohorts. The SNOW regimen involves 28-day cycles with escalated doses of nab-paclitaxel (100–175 mg/m2 on days 1 and 15) and fixed doses of oxaliplatin (65 mg/ m2 on days 1 and 15) and S-1 (80 mg/m2/day on day 1 to 14). The primary endpoints are assessment of dose limiting toxicities and determination of maximum tolerated dose to investigate the recommended dose in the subsequent phase II study. In the phase II study, the primary endpoint is objective response rate. Secondary endpoints are assessment of safety, progression-free survival, disease control rate, overall survival and time to treatment failure. Adverse events were monitored and graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0.DiscussionTriplet therapies for advanced gastric cancer patients have been evaluated in clinical trials. The SNOW regimen can be a promising new triplet therapy.Trial registrationThis study is performed at institutes that participate in Hokkaido Gastrointestinal Cancer Study Group (HGCSG) and registered as UMIN000016788. Registrated 16 March 2015.

1612TiP - Multicenter prospective cohort study to evaluate of eye disorder induced by chemotherapy including S-1 (EyeDropS study/HGCSG1604)

Background: We previously reported that S-1 chemotherapy for gastrointestinal cancer (GI cancer) induced the high incidence of eye disorders (EDs), regardless of primary cancer site, treatment regimen and administration schedule (Yagisawa M, et al. 2017 Gastrointestinal Cancers Symposium). However, because this report showed a retrospective data from single institutional small cohort by reviewing medical records, we might have underestimated the incidence of EDs. So, we have conducted this prospective cohort study to confirm the incidence of EDs induced by S-1 more precisely. Trial design: This is a multicenter prospective cohort study to evaluate the incidence of EDs and ophthalmologic changes in GI cancer patients received S-1 chemotherapy. The key eligibility criteria are as follows: 1) Histologically confirmed carcinoma in GI cancer, including esophageal, gastric, colorectal, pancreatic, and biliary tract cancer.; 2) The patient who receives chemotherapy including S-1.; 3) No prior medication of S-1.; 4) No lachrymal duct obstruction and less than three points of corner conjunctiva epithelium disorder score. All participants receive four times of ophthalmological examinations. The primary endpoint is cumulative incidence of epiphora in periods from start of S-1 chemotherapy to 12 weeks after induction S-1. The secondary endpoints are cumulative incidence of epiphora in overall S-1 chemotherapy periods, the time of onset and severity of epiphora, the situation of ophthalmological intervention, ophthalmological changes, risk factors of epiphora, and QOL. Because we supposed that incidence of epiphora at 12 weeks after induction S-1 is 10% as already reported, we calculated the sample size as 160 based on precision of the 95% confidence interval and aimed to recruit 180 patients considering the possibility of 10% dropouts. This study is sponsored by Non Profit Organization Hokkaido Gastrointestinal Cancer Study Group. Clinical trial identification: UMIN 000027192 24, June, 2017 Legal entity responsible for the study: Hokkaido Gastrointestinal Cancer Study Group Funding: None Disclosure: S. Yuki: Honoraria: Taiho Pharmaceutical Y. Sakata: Consultant fee from Taiho Pharmaceutical Co., Ltd., Y. Komatsu: Grants for research and donations: Taiho Pharmaceutical Co., Ltd., All other authors have declared no conflicts of interest.

A multicenter prospective study on the efficacy and safety of denosumab in gastrointestinal cancer patients receiving short-term periodic steroid premedication for prevention of chemotherapy-induced nausea and vomiting: ESPRESSO-02/HGCSG1602.

TPS809 Background: We previously reported that short-term periodic premedication of glucocorticoids (GCs) used with chemotherapy for gastrointestinal cancer (GIC) caused the reduction of bone mineral densities (BMD) and the increase of serum bone alkaline phosphatase (BAP) (ESPRESSO-01 study; ASCO-GI 2016 Abst.523). Surprisingly, it seems that the BMD decreasing levels due to only the 16-week GC usage in GIC chemotherapy were comparable to that of the 12-month adjuvant aromatase inhibitor therapy for early stage breast cancer patients or the 12-month androgen deprivation therapy for nonmetastatic prostate cancer patients. So we conducted this study to evaluate the efficacy and safety of denosumab for prevention of chemotherapy-induced BMD decreasing. Methods: This is a multicenter single-arm prospective study to evaluate the efficacy and safety of denosumab in GIC patients receiving the short-term periodic steroid premedication. The key eligibility criteria are as follows: 1) Histologically confirmed adenocarcinoma in GIC, including esophageal, gastric, pancreatic, and biliary cancer. ; 2) A schedules of periodical intravenous steroid administration as premedication that was weekly, biweekly, and triweekly, and in which &gt; 4-week steroid-free intervals were not allowed. ; 3) High risk patient with steroid induced secondary osteoporosis. ; 4) No prior treatment for osteoporosis. The dose of denosumab (Prolia) is 60mg administered as a single subcutaneous injection within a week before the induction of chemotherapy. All participants should receive adequate calcium and vitamin D supplementation. The primary endpoint is to investigate the BMD change and bone turnover markers (serum NTX and BAP levels) between baseline and 16 weeks after induction of chemotherapy. And the secondary endpoints are to compare and evaluate the difference of primary site, treatment regimen, dose intensity of steroids, newly bone fractures, and the FRAX output. This study is sponsored by Hokkaido Gastrointestinal Cancer Study Group. Clinical trial information: UMIN000023855.

Phase II trial of bolus 5-FU/l-LV regimen as salvage line chemotherapy for oral fluorouracil resistant unresectable gastric cancer (HGCSG1502).

TPS177 Background: S-1, oral fluorouracil agent compounding tegafur, 5-chloro-2, 4-dihydropyrimidine, and potassium oxonate for gastric cancer showed non-inferiority relative to a continuous infusion of fluorouracil in JCOG9912 trial. Similarly, in ISO-5FU10 trial, S-1 revealed non-inferiority effect compared with the treatment with bolus 5-FU/l-LV treatment. It is known that there is a different mechanism of anti-cancer effect between continuous 5-FU and bolus injection of 5-FU. Continuous infusion of 5-FU and oral fluorouracil inhibit DNA synthesis, however, bolus injection of 5-FU causes dysfunction of RNA in a concentration-dependent manner. So we considered bolus 5-FU/l-LV treatment might be useful for oral fluorouracil resistant patients with gastric cancer. Methods: This is a multi-centered single-arm prospective phase II study in Japanese patients with oral fluorouracil resistant gastric cancer. The key eligibility criteria are as follows: 1) Pathologically diagnosed gastric adenocarcinoma: 2) Unresectable advanced, metastatic, or recurrent disease; 3) resistance of S-1 or capecitabine; 4) resistance or intolerance of cisplatin or oxaliplatin, paclitaxel or docetaxel, and ramucirumab; 5) 20 years of age or older; 6) ECOG PS of 0, 1 or 2. Bolus 5-FU/l-LV regimen consists of l-LV 250mg/m2/2h iv and 5-FU 600mg/m2 iv bolus given intravenously once weekly followed by 2-week rest period, within a 8-week cycle. The primary endpoint is progression free survival rate after 1cycle administration. And the secondary endpoints are response rate, disease control rate, overall survival, progression free survival, time to treatment failure, adverse events, dose intensity and QOL by EORTC QLQ-C30. This study is recruiting in Hokkaido Gastrointestinal Cancer Study Group and registered as UMIN000018882. Clinical trial information: UMIN000018882.

The efficacy of first-line IRIS with or without bevacizumab in patients with metastatic colorectal cancer: Including multivariate analysis of two phase II studies.

603 Background: The safety and efficacy of first-line IRIS (S-1 in combination with irinotecan) and IRIS/Bev (IRIS in combination with bevacizumab [Bev]) have been evaluated in patients with metastatic colorectal cancer (mCRC). To date, no randomized studies comparing these regimens have been performed. This retrospective analysis compared efficacy data for the two regimens from separate phase II studies performed at Hokkaido Gastrointestinal Cancer Study Group (HGCSG). Methods: Patients with histologically confirmed unresectable metastatic or recurrent CRC and received no prior chemotherapy were enrolled. In the first trial, patients received irinotecan 100 mg/m2 on day 1,15 and oral S-1 40 mg/m2 twice daily on days 1-14 every 4 weeks (IRIS study: HGCSG0302). In the second trial, patients received the same regimen plus Bev 5 mg/kg on day 1,15 (IRIS/Bev study). Results: A total of 40 and 52 patients were enrolled the IRIS and IRIS/Bev studies, respectively. Patient characteristics were generally similar in both groups, whereas there were more cases of good performance status and less number of metastatic organ in IRIS/Bev group. The median overall survival was 39.6 months in IRIS/Bev, as compared with 23.4 months in IRIS, corresponding to a hazard ratio for death of 0.418 (p&lt;0.001). The median progression-free survival was 17.0 months in IRIS/Bev, as compared with 8.6 months in IRIS (hazard ratio for disease progression, 0.402; p &lt; 0.001); the corresponding response rate were 63.5 percent and 52.5 percent (p = 0.393). In a multivariate analysis of PFS and OS, IRIS/Bev was significantly associated with longer PFS and OS compared with IRIS alone. Conclusions: In this retrospective comparison of two studies, the addition of Bev to IRIS appeared to improve outcome compared with IRIS alone in the first-line treatment of patients with mCRC.

The efficacy of first-line IRIS with or without bevacizumab in patients with metastatic colorectal cancer: Analysis of two phase II studies.

e14604 Background: The safety and efficacy of first-line IRIS (S-1 in combination with irinotecan; Komatsu Y, et al. Oncology, 2011) and IRIS/Bev (IRIS in combination with bevacizumab (Bev); Komatsu Y, et al. Acta Oncol, 2012/Yuki S, et al. 2013 ASCO-GI) have been evaluated in patients with metastatic colorectal cancer (mCRC). This time, no randomized studies comparing these regimens have been performed. This retrospective analysis compared efficacy and safety data for the two regimens from separate phase II studies performed at Hokkaido Gastrointestinal Cancer Study Group (HGCSG). Methods: Patients with histologically confirmed unresectable metastatic or recurrent CRC and received no prior chemotherapy were enrolled. In the first trial, patients received irinotecan 100 mg/m2 on day 1,15 and oral S-1 40 mg/m2 twice daily on days 1-14 every 4 weeks (IRIS study: HGCSG0302). In the second trial, patients received the same regimen plus Bev 5 mg/kg on day 1,15 (IRIS/Bev study). Results: A total of 40 and 52 patients were enrolled the IRIS and IRIS/Bev studies, respectively. Patient characteristics were generally similar in both groups, whereas there were more cases of good performance status and less number of metastatic organ in IRIS/Bev group. The median overall survival was 39.6 months in IRIS/Bev, as compared with 23.4 months in IRIS, corresponding to a hazard ratio for death of 0.418 (p&lt;0.001). The median progression-free survival was 17.0 months in IRIS/Bev, as compared with 8.6 months in IRIS (hazard ratio for disease progression, 0.418; p&lt;0.001); the corresponding response rate were 63.5 percent and 52.5 percent (p=0.393).In a multivariate analysis of PFS and OS, IRIS/Bev (n=52) was significantly associated with longer PFS and OS compared with IRIS alone (n=40). Conclusions: In this retrospective comparison of two studies, the addition of Bev to IRIS appeared to improve outcome compared with IRIS alone in the first-line treatment of patients with mCRC.

Phase II trial of combined chemotherapy with irinotecan, S-1, and bevacizumab (IRIS/Bev) in patients with metastatic colorectal cancer (mCRC): Hokkaido Gastrointestinal Cancer Study Group (HGCSG) trial—Comparison of the efficacy of KRAS status.

536 Background: Mutations of the KRAS gene were identified as a predictive marker in mCRC for anti-EGFR antibody. Previously reported data suggest that the longer overall survival (OS) observed with bevacizumab (BV) treatment in mCRC is independent of alterations in the KRAS status. We analized efficacy of BV combined irinotecan and S-1 (IRIS/Bev) in mCRC relative to KRAS status. Methods: In the retrospective analysis (n=53) of patients who participated in the Phase II trial of IRIS/Bev, additional statistical analyses were done with data from KRAS mutational analyses. In this trial, eligible patients had to have mCRC with a confirmed diagnosis of adenocarcinoma, an age of &gt;20 years, and no history of prior chemotherapy. S-1 40-60 mg twice daily p.o. was given on days 1-14 and irinotecan 100 mg/m2 and bevacizumab 5 mg/kg i.v. were given on days 1 and 15 of a 28-day cycle. The Response Evaluation in Solid Tumors (RECIST) criteria version 1.0 was used to assess tumor response. The Kaplan–Meier method was used to determine Progression-free survival (PFS) and OS. Log-rank test was used to compare with mutant or wild-type KRASin terms of PFS and OS. All statistical tests were performed using SPSS. Results: The target number of 53 patients was enrolled as of March 2009. KRAS status was assessed in 43 patients (wild = 27, mutant = 16). Response rate was 63.0% with wild-type and 68.8% with mutant-type KRAS, that was not significant (p=0.752). The median Progression-free survival was 17.1 months with wild-type and 22.7 months with mutant-type KRAS, that was not significant (p=0.531). And median OS was 49.0 months with wild-type and 38.0 months with mutant-type KRAS, that was not significant(p=0.906) as well. Conclusions: IRIS/Bev provides clinical benefit in patients with mCRC expressing either mutant or wild-type KRAS. Randomized control trial comparing this regimen with oxaliplatin containing regimen(XELOX or mFOLFOX6 plus bevacizumab: TRICOLORE study) is already started. Comparison of the efficacy of KRAS status is also planned in this study. Clinical trial information: NCT00569790.

An open, multicenter, phase II clinical trial to evaluate efficacy and safety of S-1 split cisplatin in patients with advanced gastric cancer (AGC): HGCSG0702—Safety analysis.

121 Background: From the results of SPIRITS trial, S-1 plus cisplatin has been regarded as standard first-line chemotherapy for patients with AGC in Japan. However, many facilities are forced hospitalization of hydration upon administration of high dose Cisplatin (60mg/m2). Therefore, in Hokkaido Gastrointestinal Cancer Study Group (HGCSG), to investigate the safety and efficacy, we conducted a multicenter phase II clinical trials of S-1 plus split cisplatin as a therapeutic strategy that can be administered in the outpatient. Methods: Eligibility criteria included pathologically confirmed AGC; no prior chemotherapy; Age 20 to 75, ECOG performance status (PS) of 0 to 1; adequate organ function; and written informed consent. S-1 (40-60 mg depending on patients body surface area) was given orally, twice daily for 3 consecutive weeks, and 30 mg/m2 cisplatin was given intravenously on day 1 and 15, followed by 2-week rest period, within a 5-week cycle. Primary endpoint was the response rate (RR), and secondary endpoints were progression-free survival, overall survival, safety profile, and duration of hospitalization. Results: Between Mar 2008 and Mar 2012, 40 pts were enrolled. Patients characteristics were as follows: median age 63 years (range 41-75), Male: female 30:10, PS 0:1 33:7. Median no. of cycles was 3. The most common non-hematological adverse events (AE) were anorexia (70%), nausea (60%), fatigue (60%) and diarrhea (48%) and hematological AE were anemia (88%), neutropenia (83%), leukocytopenia (68%) and thrombocytopenia (60%). The main grade 3-4 AE were neutropenia (40%), anemia (30%), anorexia (30%) and fatigue (15%). These AE were as expected. The median dose intensity of S-1 was 270mg/m2/week (relative dose intensity (RDI) 80%), and cisplatin was 10.1mg/m2/week (RDI 84%). These toxicities were tolerable and manageable. No treatment-related death was observed. Conclusions: We conclude that this S-1 plus split cisplatin regimen was well tolerated in the treatment of AGC, and most patients could be administered in the outpatient. We are planning the final efficacy analysis for February 2013.

Phase II trial of combined chemotherapy with irinotecan, S-1, and bevacizumab (IRIS/Bev) in patients with metastatic colorectal cancer (mCRC): Final analysis—Hokkaido Gastrointestinal Cancer Study Group (HGCSG) trial.

460 Background: The FIRIS study (Muro K et al. Lancet Oncol 2010;11:853–860) previously demonstrated the non-inferiority of Irinotecan plus S-1 (IRIS) to FOLFIRI for mCRC, with progression-free survival (PFS) as the primary endpoint. We previously reported that IRIS plus bevacizumab (IRIS/Bev) is very effective as first-line treatment (Komatsu Y et al. Acta Oncol. 2012 May 4). We now report the final results of this study. Methods: Eligible patients had to have mCRC with a confirmed diagnosis of adenocarcinoma, an age of &gt;20 years, ECOG performance status (PS) of 0-1, and no history of prior chemotherapy. S-1 (40-60 mg depending on patients body surface area) was given orally, twice daily for 2 consecutive weeks, and 100 mg/m2irinotecan and 5 mg/kg bevacizumab was given intravenously on day 1 and 15, followed by 2-week rest period, within a 4-week cycle. The primary endpoint was safety. The secondary endpoints included overall response (OR), PFS, and overall survival (OS). Results: A total of 53 patients were enrolled from October 2007 through March 2009. The results were reported for 52 patients with evaluable lesions. The clinical characteristics of the patients were as follows. The median age was 63.5 years (range, 48 to 82). The male:female ratio was 3:2. The most common grade 3 or 4 adverse events were neutropenia (27%) and diarrhea (17%). Grade 3 or 4 hypertension (21%) was attributed to bevacizumab, but there were no life-threatening adverse events, such as gastrointestinal perforation. On an intention-to-treat basis, OR was 63.5% [95% confidence interval (CI) 50.4-76.5%], and the disease control rate was 94.2%. With a median follow-up time of 51.7 months, median PFS was 17.0 months (95%C.I. 14.2-19.8 months) and median survival time was 39.6 months (95%C.I. 34.2-45.0 months). Conclusions: IRIS/Bev is a remarkably active and generally well-tolerated first-line treatment for patients with mCRC. Randomized control trial comparing this regimen with oxaliplatin containing regimen(XELOX or mFOLFOX6 plus bevacizumab: TRICOLORE study) is already started. Clinical trial information: NCT00569790.

WS1-4 - Updated Analysis: Phase II Trial of Combined Chemotherapy with Irinotecan, S-1, and Bevacizumab (IRIS/Bev) in Patients with Metastatic Colorectal Cancer: Hokkaido Gastrointestinal Cancer Study Group (HGCSG) Trial

ABSTRACT Background The FIRIS study (Muro K et al. Lancet Oncol 2010; 11: 853–860) previously demonstrated the non-inferiority of Irinotecan plus S-1(IRIS) to FOLFIRI for metastatic colorectal cancer (mCRC), with progression-free survival (PFS) as the primary end point. We previously reported that IRIS plus bevacizumab (IRIS/bev) is very effective as first-line treatment (Komatsu Y et al. ESMO 2010). We now report the updated results of this study. Methods Eligible patients had to have mCRC with a confirmed diagnosis of adenocarcinoma, an age of >20 years, ECOG performance status (PS) of 0-1, and no history of prior chemotherapy. S-1 40-60 mg twice daily p.o. was given on days 1–14 and irinotecan 100 mg/m2 and bevacizumab 5 mg/kg i.v. were given on days 1 and 15 of a 28-day cycle. The primary end point was safety. The secondary end points included overall response (OR), progression-free survival (PFS), and overall survival (OS). Results The target number of 53 patients was enrolled as of March 2009. The results are reported for 52 patients with evaluable lesions. The clinical characteristics of the patients were as follows. The median age was 63.5 years (range, 48 to 82). The male:female ratio was 3:2. The performance status on the Eastern Cooperative Oncology Group scale was 0. In January 2012, on safety analysis, the incidence of grade 3 or 4 neutropenia was 27%. The incidences of other grade 3 or 4 adverse reactions were as follows: diarrhea, 17%; anorexia, 4%; stomatitis, 2%; hypertension, 21%; and gastrointestinal perforation, 0%. The overall response rate was 63.5%. Three patients had complete response. Thirty patients had partial response, 16 had stable disease, none had progressive disease, and 3 were not evaluable. Median progression-free survival was 17.0 months and the median survival time was 39.6 months. Seven patients (13.5%) treated with IRIS/Bev underwent surgery with curative intent. Conclusions IRIS/Bev is a remarkably active and generally well-tolerated first-line treatment of patients with mCRC. The treatment resulted in a high resectability rate, which could potentially result in an improved cure rate. Randomized control trial comparing IRIS/Bev with oxaliplatin containing regimen (XELOX or mFOLFOX6 plus bevacizumab) is being planned.

592P - Phase II Trial of Combined Chemotherapy with Irinotecan, S-1, and Bevacizumab (IRIS/BEV) In Patients with Metastatic Colorectal Cancer -Updated Analysis-. Hokkaido Gastrointestinal Cancer Study Group (HGCSG) Trial

ABSTRACT Background The FIRIS study (Muro K et al. Lancet Oncol 2010;11:853–860) previously demonstrated the non-inferiority of Irinotecan plus S-1(IRIS) to FOLFIRI for metastatic colorectal cancer(mCRC), with progression-free survival (PFS) as the primary endpoint. We previously reported that IRIS plus bevacizumab (IRIS/bev) is very effective as first-line treatment (Komatsu Y et al. ESMO 2010). We now report the updated results of this study. Methods Eligible patients had to have mCRC with a confirmed diagnosis of adenocarcinoma, an age of >20 years, ECOG performance status (PS) of 0-1, and no history of prior chemotherapy. S-1 40-60 mg twice daily p.o. was given on days 1-14 and irinotecan 100 mg/m2 and bevacizumab 5 mg/kg i.v. were given on days 1 and 15 of a 28-day cycle. The primary endpoint was safety. The secondary endpoints included overall response (OR), progression-free survival (PFS), and overall survival (OS). Results The target number of 53 patients was enrolled as of March 2009. The results are reported for 52 patients with evaluable lesions. The clinical characteristics of the patients were as follows. The median age was 63.5 years (range, 48 to 82). The male:female ratio was 3:2. The performance status on the Eastern Cooperative Oncology Group scale was 0. In January 2012, on safety analysis, the incidence of grade 3 or 4 neutropenia was 27%. The incidences of other grade 3 or 4 adverse reactions were as follows: diarrhea, 17%; anorexia, 4%; stomatitis, 2%; hypertension, 21%; and gastrointestinal perforation, 0%. The overall response rate was 63.5%. Three patients had complete response. Thirty patients had partial response, 16 had stable disease, none had progressive disease, and 3 were not evaluable. Median progression-free survival was 17.0 months and median survival time was 39.6 months. Conclusions IRIS/Bev is a remarkably active and generally well-tolerated first-line treatment for patients with mCRC. Randomized control trial comparing this regimen with oxaliplatin containing regimen (XELOX or mFOLFOX6 plus bevacizumab: TRICOLORE study) is already started. Disclosure All authors have declared no conflicts of interest.

Phase II trial of combined chemotherapy with irinotecan, S-1, and bevacizumab (IRIS/Bev) in patients with metastatic colorectal cancer: Update analysis—Hokkaido Gastrointestinal Cancer Study Group (HGCSG) trial.

3593 Background: The FIRIS study (Muro K et al. Lancet Oncol 2010;11:853–860) previously demonstrated the non-inferiority of Irinotecan plus S-1(IRIS) to FOLFIRI for metastatic colorectal cancer(mCRC), with progression-free survival (PFS) as the primary endpoint. We previously reported that IRIS plus bevacizumab(IRIS/bev) is very effective as first-line treatment (Komatsu Y et al. ESMO 2010). We now report the updated results of this study. Methods: Eligible patients had to have mCRC with a confirmed diagnosis of adenocarcinoma, an age of &gt;20 years, ECOG performance status (PS) of 0-1, and no history of prior chemotherapy. S-1 40-60 mg twice daily p.o. was given on days 1-14 and irinotecan 100 mg/m2 and bevacizumab 5 mg/kg i.v. were given on days 1 and 15 of a 28-day cycle. The primary endpoint was safety. The secondary endpoints included overall response (OR), progression-free survival (PFS), and overall survival (OS). Results: The target number of 53 patients was enrolled as of March 2009. The results are reported for 52 patients with evaluable lesions. The clinical characteristics of the patients were as follows. The median age was 63.5 years (range, 48 to 82). The male:female ratio was 3:2. The performance status on the Eastern Cooperative Oncology Group scale was 0. In January 2012, on safety analysis, the incidence of grade 3 or 4 neutropenia was 27%. The incidences of other grade 3 or 4 adverse reactions were as follows: diarrhea, 17%; anorexia, 4%; stomatitis, 2%; hypertension, 21%; and gastrointestinal perforation, 0%. The overall response rate was 63.5%. Three patients had complete response. Thirty patients had partial response, 16 had stable disease, none had progressive disease, and 3 were not evaluable. Median progression-free survival was 17.0 months and median survival time was 39.6 months. Conclusions: IRIS/Bev is a remarkably active and generally well-tolerated first-line treatment for patients with mCRC. Randomized control trial comparing this regimen with oxaliplatin containing regimen(XELOX or mFOLFOX6 plus bevacizumab) is being planned.

Phase II clinical study of combination therapy with irinotecan and S-1(IRIS) for inoperable recurrent advanced colorectal cancer (2nd report): For Hokkaido Gastrointestinal Cancer Study Group (HGCSG)

4105 Background: We planned to conduct a phase II clinical study of combination therapy with irinotecan and S-1, a new oral anticancer drug of the fluorinated pyrimidine type. We reported the interim reports of this study in colorectal cancer patients at ASCO 2006. Methods: The antitumor effect was the primary endpoint, while the safety, progression-free survival time, and median survival time were the secondary endpoints. The subjects were untreated patients with inoperable advanced colorectal cancer aged 20–75 years. Irinotecan was administered at a dose of 100 mg/m2 (on days 1 and 15) as an intravenous infusion over 90 minutes, and oral S-1 (40 mg/m2) was administered after breakfast and dinner and then withdrawn for 2 weeks. Results: Forty patients were enrolled in the present study. There were 23 men and 17 women. The median age was 62 years (range: 34 to 74 years). Two patients showed grade 4 neutropenia, but the next course could be given safely after dose reduction. Three patients had grade 3 diarrhea, but therapy could be continued with addition of an antidiarrhea drug. No other serious adverse reactions occurred (either hematological or non-hematological), and all patients could receive therapy safely on an outpatient basis. Forty pts. are evaluable for efficacy: RR was 52.5% (CR 1, PR 20, SD 17, PD 2, 95% CI, 37–68%) and Disease Control Rate (CR+PR+SD) was seen in 96.0% of pts. PFS of this regimen is 311 days. MST is not reached. Conclusions: IRIS therapy achieved a high response rate and could be given safely. These findings suggest that the therapy has potential as first-line treatment for inoperable advanced recurrent colorectal cancer. It seems that IRIS is a good treatment equal to FOLFIRI. Non-inferiority randomized phase III trial of IRIS vs. mFOLFOX6 (IFOX study) was planned, and it has been already started now. The latest data will be reported at the meeting. No significant financial relationships to disclose.

Phase II clinical study of combination therapy with irinotecan and S-1(IRIS) for inoperable recurrent advanced colorectal cancer: Hokkaido Gastrointestinal Cancer Study Group study HGCSG-0302)

3589 Background: We planned to conduct a phase II clinical study of combination therapy with irinotecan and S-1, a new oral anticancer drug of the fluorinated pyrimidine type. We reported the interium reports of this study in colorectal cancer patients at GI cancer Symposium 2006. Methods: The antitumor effect was the primary endpoint, while the safety, progression-free survival time, and median survival time were the secondary endpoints. The subjects were untreated patients with inoperable advanced colorectal cancer aged 20–75 years. Irinotecan was administered at a dose of 100 mg/m2 (on days 1 and 15) as an intravenous infusion over 90 minutes, and oral S-1 (40 mg/m2) was administered after breakfast and dinner and then withdrawn for 2 weeks. Results: Forty patients were enrolled in the present study. There were 23 men and 17 women. The median age was 62 years (range: 34 to 74 years). Two patient showed grade 4 neutropenia, but the next course could be given safely after dose reduction. Three patients had grade 3 diarrhea, but therapy could be continued with addition of an antidiarrheal drug. No other serious adverse reactions occurred (either hematological or non-hematological), and all patients could receive therapy safely on an outpatient basis. Interim analysis suggested excellent results, with a response rate of 50%. To date, 231 cycles (median 8, range 1–19) have been administered. Median relative dose intensity was 97% for S-1 and 87% for irinotecan. 36 pts are evaluable for efficacy: RR was 47.2% (95% CI, 30.9–63.5%) and Disease Control Rate (PR + SD) was seen in 94.4% of pts. PFS of this regimen is 320 days. MST is not reached. Conclusions: IRIS therapy achieved a high response rate and could be given safely. These findings suggest that the therapy has potential as first-line treatment for inoperable advanced recurrent colorectal cancer. It seems that IRIS is a good treatment equal to FOLFIRI. In addition, this regimen could qualify as a candidate for future combination therapy with a molecular-targeting drug. The latest data will be reported at the meeting. No significant financial relationships to disclose.

773 PUBLICATION Phase I study of docetaxel, cisplatin and 5-fluorouracil(TPF) as first-line chemotherapy in patients with advanced esophageal cancer. —Hokkaido Gastrointestinal Cancer Study Group (HGCSG) study-

S-1 is a novel oral anticancer drug, composed of tegafur (FT), gimestat (CDHP) and otastat potassium (Oxo) in a molar ratio of 1:0.4:1, based on the biochemical modulation of 5-fluorouracil (5-FU). CDHP inhibits dihydropyrimidine dehydrogenase (DPD), an enzyme which degrades 5-FU, and maintains prolonged 5-FU concentrations in the blood and tumours. Oxo is distributed in the gastrointestinal tract at a high concentration after oral administration and alleviates gastrointestinal toxicity due to 5-FU. S-1 improves the tumour-selective toxicity of 5-FU by the actions of two modulators, CDHP and Oxo. We conducted a late phase II clinical trial of S-1 as an open trial in patients with advanced gastric cancer, to confirm its antitumour effect and adverse reactions. 51 patients with advanced gastric cancer were enrolled in the trial. S-1 was administered orally twice daily after meals, at a standard dose of 80 mg/m2/day. One course consisted of consecutive administration for 28 days and 14 days’ rest. Administration was repeated over four courses. A complete response was obtained in 1 patient and partial responses in 24 patients, producing a response rate of 49% (25/51) (95% confidence interval (CI) 35.9–62.3%). The incidence of adverse reactions was 78% (40/51) and that of adverse reactions of grades 3 and 4 was 20%. Adverse reactions of grades 3 and 4 included a decrease in the haematocrit, leucopenia, granulocytopenia, diarrhoea, malaise and proteinuria. No serious unexpected adverse reactions were observed. In conclusion, S-1 was effective and well tolerated in patients with advanced gastric cancer.