Makio Gamoh

Mutations of the p53 gene, including an intronic point mutation, in colorectal tumors

In this study, analysis of structural changes of the p53 gene in colorectal tumors revealed point mutations detected in 8 of 14 carcinomas and 2 of 2 adenomas. Of these 10 cases with point mutations, eight had one or more missense mutations, one had a nonsense mutation, and the remaining one had, interestingly, an intronic point mutation with subsequent activation of a cryptic splice donor site in the flanking exon. This report contains the first identification of an intronic point mutation of the p53 gene in a colorectal cancer case.

Phase I/II study of sequential therapy with irinotecan and S-1 for metastatic colorectal cancer

Background:Both irinotecan (CPT-11) and S-1 are active against colorectal cancer; however, as S-1 is a prodrug of 5-fluorouracil (5-FU), 5-FU and its metabolites might inhibit the antitumour effect of CPT-11. Therefore, we designed a sequential combination, in which CPT-11 infusion was given on day 1 and S-1 was given orally at 80 mg m−2 per day on days 3–16 every 3 weeks.Methods:Twelve patients entered the phase I study, and the recommended doses were determined as a CPT-11 dose of 150 mg m−2 and an S-1 dose of 80 mg m−2.Results:In all, 36 patients entered the phase II study, of whom 4 and 16 had complete and partial responses. The overall response rate was 55.6% (95% confidence interval, 38.1–72.1%), and median progression-free survival was 7.7 months (95% confidence interval, 4.8–12.6 months). Grade 3 neutropenia was the most common haematological toxicity and occurred in 6.5% of 215 treatment courses. Grade 3 non-haematological toxicities included anorexia (1.4%) and diarrhoea (0.9%). There was no grade 4 toxicity of any kind.Conclusion:Our results suggest that this regimen is convenient, safe and promising, compared with conventional regimens for patients with metastatic colorectal cancer.

Biweekly administration regimen of docetaxel combined with CPT-11 in patients with inoperable or recurrent gastric cancer

AbstractBackground. Both docetaxel (TXT) and irinotecan (CPT-11) are active chemotherapeutic agents for gastric cancer. We designed a biweekly administration regimen of TXT combined with CPT-11 for 4 weeks as one cycle in patients with inoperable or recurrent gastric cancer, and conducted a dose-escalation study. Methods. Patients with histologically confirmed gastric cancer were treated with the regimen. The dosage levels of TXT and CPT-11 were as follows: level 1, 30 mg/m2 and 50 mg/m2; level 2, 35 and 50 mg/m2; level 3, 40 and 50 mg/m2; level 4, 40 and 60 mg/m2; and level 5, 50 and 60 mg/m2. The dose escalation was based on the dose-limiting toxicity (DLT) observed during the first cycle. Results. Grade 4 neutropenia was observed at level 3, but no other DLT was observed at less than level 4 during the first cycle. However, three patients at level 3 could not continue treatment without a decrease in the dosage after the second cycle. Based on these results, level 2 was considered to be the clinically recommended dosages. Conclusion. Biweekly TXT and CPT-11 was well tolerated. The recommended dosages of TXT and CPT-11 for a phase II trial are 35 mg/m2 and 50 mg/m2, respectively.

Study protocol of the TRICOLORE trial: a randomized phase III study of oxaliplatin-based chemotherapy versus combination chemotherapy with S-1, irinotecan, and bevacizumab as first-line therapy for metastatic colorectal cancer

BackgroundMetastatic colorectal cancer carries a poor prognosis and cannot be cured by currently available therapy. Chemotherapy designed to prolong survival and improve the quality of life (QOL) of patients is the mainstay of treatment. Standard regimens of FOLFOX/bevacizumab and CapeOX/bevacizumab can cause neurotoxicity, potentially disrupting treatment. The results of 3 phase II studies of combination therapy with S-1, irinotecan, and bevacizumab showed comparable efficacy to mFOLFOX6/bevacizumab and CapeOX/bevacizumab, without severe neurotoxicity. Therefore, the establishment and evaluation of S-1-containing irinotecan-based regimens for first-line treatment are expected to become more important.MethodsThe TRICOLORE trial is a multicenter, randomized, open-label, controlled phase III study which aims to evaluate the non-inferiority of combination therapy with S-1/irinotecan/bevacizumab (a 3-week regimen [SIRB] or 4-week regimen [IRIS/bevacizumab]) to oxaliplatin-based standard treatment (mFOLFOX6/bevacizumab or CapeOX/bevacizumab) in patients with metastatic colorectal cancer who had not previously received chemotherapy. Patients will be randomly assigned to either the control group (mFOLFOX6/bevacizumab or CapeOX/bevacizumab) or study group (SIRB or IRIS/bevacizumab). The target sample size is 450 patients. The primary endpoint is progression-free survival (PFS), and the secondary endpoints are overall survival (OS), response rate (RR), time to treatment failure (TTF), relative dose intensity (RDI), the incidence and severity of adverse events, quality of life (QOL), quality-adjusted life years (QALY), health care costs, and relations between biomarkers and treatment response (translational research, TR).DiscussionThe results of this study will provide important information that will help to improve the therapeutic strategy for metastatic colorectal cancer, and we believe that this study is very meaningful from the perspective of comparative effectiveness research.Trial registrationUMIN000007834

Phase II Trial of Cetuximab plus Irinotecan for Oxaliplatin- and Irinotecan-Based Chemotherapy-Refractory Patients with Advanced and/or Metastatic Colorectal Cancer: Evaluation of Efficacy and Safety Based on KRAS Mutation Status (T-CORE0801)

Background: Mutations in the KRAS gene have been identified as negative predictors of response to anti-epidermal growth factor receptor (EGFR) monoclonal antibody therapy by patients with metastatic colorectal cancer (mCRC). However, it has been based on the study of mainly Caucasian mCRC patients. This prospective study investigated the relationship between the mutation status of EGFR-related genes including KRAS and the response rate (RR) to cetuximab plus irinotecan therapy in Japanese mCRC patients. Methods: Samples taken from 43 chemotherapy-refractory mCRC patients who had undergone cetuximab plus irinotecan therapy at 11 medical centers in Japan were subjected to direct DNA sequencing to determine the KRAS, BRAF, PIK3CA, NRAS, and AKT1 mutation status. The clinical outcome after the treatment was evaluated for each mutation status. Results:KRAS mutations were detected in 31.7% of 41 eligible patients. The RR to cetuximab plus irinotecan therapy was found to be 17.9 and 0% in the KRAS wild-type and mutant subgroups, respectively. Conclusion: Despite the identification of a lower-than-expected RR to treatment by the KRAS wild-type subgroup, KRAS mutation status appears to be a useful predictive marker of response to cetuximab plus irinotecan therapy in Japanese mCRC patients.

Safety Verification Trials of mFOLFIRI and Sequential IRIS + Bevacizumab as First- or Second-Line Therapies for Metastatic Colorectal Cancer in Japanese Patients

Objective: S-1 is effective in sequential combination with irinotecan (IRIS) in treating metastatic colorectal cancer. We conducted a randomized phase II trial of modified leucovorin, fluorouracil and irinotecan (mFOLFIRI) + bevacizumab and sequential IRIS + bevacizumab as first- or second-line therapies. Methods: Sixty metastatic colorectal cancer patients were randomly assigned to receive mFOLFIRI + bevacizumab or sequential IRIS + bevacizumab (7.5 mg/kg of bevacizumab and 150 mg/m2 of irinitecan, and 80 mg/m2/day of S-1 orally from day 3 until day 16 as a 3-week course). The primary endpoint was the safety of each method until week 12, with the secondary endpoint being the comparison of the safety and efficacy of the two methods. Results: The safety of the two treatments was comparable, except that G3 anorexia and diarrhoea were less frequent with sequential IRIS + bevacizumab. The overall response rate was 62% [95% confidence interval (CI) 40.1–79.8] versus 72% (95% CI 50.6–86.2), and progression-free survival was 324 days (95% CI 247–475) versus 345 days (95% CI 312–594) with mFOLFIRI + bevacizumab versus IRIS + bevacizumab, respectively. Conclusion: Sequential IRIS + bevacizumab is a safe and effective method of systemic chemotherapy against metastatic colorectal cancer and is compatible with mFOLFIRI + bevacizumab.

S-1 and irinotecan plus bevacizumab versus mFOLFOX6 or CapeOX plus bevacizumab as first-line treatment in patients with metastatic colorectal cancer (TRICOLORE): a randomized, open-label, phase III, noninferiority trial

Abstract Background Combination therapy with oral fluoropyrimidine and irinotecan has not yet been established as first-line treatment of metastatic colorectal cancer (mCRC). We carried out a randomized, open-label, phase III trial to determine whether S-1 and irinotecan plus bevacizumab is noninferior to mFOLFOX6 or CapeOX plus bevacizumab in terms of progression-free survival (PFS). Patients and methods Patients from 53 institutions who had previously untreated mCRC were randomly assigned (1 : 1) to receive either mFOLFOX6 or CapeOX plus bevacizumab (control group) or S-1 and irinotecan plus bevacizumab (experimental group; a 3-week regimen: intravenous infusions of irinotecan 150 mg/m2 and bevacizumab 7.5 mg/kg on day 1, oral S-1 80 mg/m2 twice daily for 2 weeks, followed by a 1-week rest; or a 4-week regimen: irinotecan 100 mg/m2 and bevacizumab 5 mg/kg on days 1 and 15, S-1 80 mg/m2 twice daily for 2 weeks, followed by a 2-week rest). The primary end point was PFS. The noninferiority margin was 1.25; noninferiority would be established if the upper limit of the 95% confidence interval (CI) for the hazard ratio (HR) of the control group versus the experimental group was less than this margin. Result Between June 2012 and September 2014, 487 patients underwent randomization. Two hundred and forty-three patients assigned to the control group and 241 assigned to the experimental group were included in the primary analysis. Median PFS was 10.8 months (95% CI 9.6–11.6) in the control group and 14.0 months (95% CI 12.4–15.5) in the experimental group (HR 0.84, 95% CI 0.70–1.02; P < 0.0001 for noninferiority, P = 0.0815 for superiority). One hundred and fifty-seven patients (64.9%) in the control group and 140 (58.6%) in the experimental group had adverse events of grade 3 or higher. Conclusion S-1 and irinotecan plus bevacizumab is noninferior to mFOLFOX6 or CapeOX plus bevacizumab with respect to PFS as first-line treatment of mCRC and could be a new standard treatment. Clinical trials number UMIN000007834

Evaluation of Mizoribine as an Immunosuppressant in Subrenal Capsule Assay Using Immunocompetent Mice

We studied the application of mizoribine (MZR) to normal immunocompetent mice in subrenal capsule assay (SRCA) by means of tumor growth curve determination, histological analysis and autoradiography. At 400 mg/kg, MZR prolonged the actual tumor growth and moderately reduced the host reaction. Doses below 200 mg/kg did not effectively suppress the host reaction. The maximal weight loss of mice in the 400 mg/kg group reached 29%, but did not exceed 10% within 8 days. Hence, we applied 400 mg/kg of MZR to SRCA for up to eight days for cancer chemotherapy testing. This dose of MZR did not affect the labeling index of tumor cells compared with the control.

Safety data from the phase III Japanese ACHIEVE trial: part of an international, prospective, planned pooled analysis of six phase III trials comparing 3 versus 6 months of oxaliplatin-based adjuvant chemotherapy for stage III colon cancer

Background The International Duration Evaluation of Adjuvant chemotherapy project investigated whether a shorter duration of oxaliplatin-based adjuvant chemotherapy was as effective as 6 months of identical chemotherapy for resected stage III colon cancer. As part of this project, we report safety data from the Japanese ACHIEVE study (JFMC47-1202-C3). Patients and methods ACHIEVE was an open-label, multicentre trial randomising patients with stage III colon cancer to receive 3 m or 6 m of mFOLFOX6/CAPOX after surgery. Choice of regimen was declared before randomisation by a site investigator. Results Between August 2012 and June 2014, 1313 patients were enrolled and, of those, 1277 were analysed for the safety analysis, with 635 in arm 6 (mFOLFOX6, n=158; CAPOX, n=477) and 642 in arm 3 (mFOLFOX6, n=161; CAPOX, n=481). Grade 3 or worse peripheral sensory neuropathy (PSN) developed in 5%/0.6% of patients receiving mFOLFOX6 in arm 6/3 (p=0.019) and 6%/1% of those receiving CAPOX in arm 6/3 (p<0.001). Similarly, grade 2 or worse PSN developed in 36%/11% of patients receiving mFOLFOX6 in arm 6/3 (p<0.001) and 37%/14% of those receiving CAPOX in arm 6/3 (p<0.001). An association between baseline creatinine clearance (CCr) and adverse events (AEs) was found that patients with CAPOX were significantly more likely to develop AEs ≥grade 3 when they had a CCr ≤50 (OR 1.67; p=0.048). Conclusions We confirmed in the Japanese population that the shorter duration of adjuvant chemotherapy resulted in a significant reduction of PSN. In patients with CAPOX, renal function was significantly related to severe AEs. Trial registration number UMIN000008543, Results.

Tumor lysis syndrome after treatment with sorafenib for hepatocellular carcinoma

Tumor lysis syndrome (TLS) is a potential life-threatening complication in cancer therapy, although it is rare in nonhematologic malignancy. Sorafenib, an oral multi tyrosine kinase inhibitor, has demonstrated survival benefit for patients with advanced hepatocellular carcinoma (HCC). A 70-year-old man with massive HCC was treated with sorafenib. Seven days after the start of treatment, he developed acute renal failure and elevation of hepatic enzymes, suggesting TLS. Abdominal CT depicted multiple hemorrhages in his liver. He was treated with emergent hemodialysis. He was discharged from the hospital, but mild renal dysfunction remained. We should pay careful attention to treatment of patients who have large HCC with sorafenib.