A Phase II Trial of Trifluridine/Tipiracil in Combination with Cetuximab Rechallenge in Patients with RAS Wild-Type mCRC Refractory to Prior Anti-EGFR Antibodies: WJOG8916G Trial.

BACKGROUND: Trifluridine/tipiracil (FTD/TPI) improved the overall survival in patients with metastatic colorectal cancer (mCRC) who had previously received standard chemotherapies; however, the clinical outcomes remain poor. OBJECTIVE: A multicenter phase II study aimed to assess the efficacy and safety of FTD/TPI plus cetuximab rechallenge. PATIENTS AND METHODS: Patients with histologically confirmed RAS wild-type mCRC refractory to prior anti-epidermal growth factor receptor (anti-EGFR) antibody were enrolled and treated with FTD/TPI (35 mg/m2 twice daily on days 1-5 and 8-12) plus cetuximab (initially 400 mg/m2, followed by weekly 250 mg/m2) every 4 weeks. The primary endpoint was disease control rate (DCR), expecting a target DCR of 65% and null hypothesis of 45% with 90% power and 10% one-sided alpha error. Gene alterations of RAS, BRAF, EGFR, PIK3CA, ERBB2, and MET in pre-treatment circulating tumor DNA were evaluated using the Guardant360 assay. RESULTS: A total of 56 patients (median age 60 years; left-sided tumors 91%; objective partial or complete response during the prior anti-EGFR therapy 61%) were enrolled. The DCR was 54% (80% confidence interval [CI] 44-63; P = 0.12), with a partial response rate of 3.6%. Median progression-free survival (PFS) was 2.4 months (95% CI 2.1-3.7). In the circulating tumor DNA analysis, patients without any alterations of the six genes (n = 20) demonstrated higher DCR (75% vs. 39%; P = 0.02) and longer PFS (median 4.7 vs. 2.1 months; P < 0.01) than those with any gene alterations (n = 33). The most common grade 3/4 hematologic adverse event was neutropenia (55%). No treatment-related deaths occurred. CONCLUSIONS: FTD/TPI plus cetuximab rechallenge did not demonstrate clinically meaningful efficacy in all mCRC patients, but might be beneficial for the molecularly selected population.

Genomic Landscape of Primary Tumor Site and Clinical Outcome for Patients with Metastatic Colorectal Cancer Receiving Standard-of-Care Chemotherapy.

BACKGROUND: Primary tumor site and genomic status are utilized for regimen selection in metastatic colorectal cancer; however, the impact on clinical practice is not well known. OBJECTIVE: We aimed to clarify the impact of primary tumor site and genomic status on clinical practice in metastatic colorectal cancer. METHODS: The relationship between primary tumor site, genomic alterations, and clinical outcomes was evaluated in patients with untreated metastatic colorectal cancer using real-world data of a prospective observational study, SCRUM-Japan GI-SCREEN with clinical and genomic data set in 1011 patients enrolled from February 2015 to March 2017. RESULTS: Five hundred and sixty-one patients were eligible for this study. Patients with right-sided tumors had a significantly worse survival, left-sided tumors with wild-type RAS had favorable outcomes when treated with anti-epidermal growth factor receptor monoclonal antibodies, and cecum tumors had poor prognosis when treated with bevacizumab. The rate of gene alterations varied considerably depending on the primary site. In addition, gene alterations of KRAS, BRAF, SMAD4, or TP53 had individually different contributions to survival from site to site. KRAS, BRAF, PTEN, or SMAD4 mutations were associated with efficacy of bevacizumab or anti-epidermal growth factor receptor monoclonal antibodies. CONCLUSIONS: Primary tumor site is a clinically useful biomarker to predict survival in patients with metastatic colorectal cancer treated with first-line chemotherapy. Moreover, the prognostic or predictive value of several gene alterations by primary tumor site should be considered in clinical practice.

Rationale and design of the TRUSTY study: a randomised, multicentre, open-label phase II/III study of trifluridine/tipiracil plus bevacizumab versus irinotecan, fluoropyrimidine plus bevacizumab as second-line treatment in patients with metastatic colorectal cancer progressive during or following first-line oxaliplatin-based chemotherapy.

BACKGROUND: Trifluridine/tipiracil is an oral agent approved for the treatment of patients with metastatic colorectal cancer (mCRC). Trifluridine is an antineoplastic thymidine analogue, and tipiracil improves its bioavailability. A phase I/II C-TASK FORCE study of trifluridine/tipiracil plus bevacizumab for patients with refractory mCRC demonstrated promising efficacy results with mild toxicity profile. It is important that quality of life be preserved in patients with mCRC without compromising their prognosis. Here, we outline the TRiflUridine/tipiracil in Second-line sTudY phase II/III study (JapicCTI-173618), designed to demonstrate non-inferiority in overall survival of trifluridine/tipiracil plus bevacizumab compared with irinotecan, fluoropyrimidine and bevacizumab combination regimens as second-line treatment in patients with mCRC. PATIENTS AND METHODS: Eligible patients have confirmed unresectable advanced or recurrent colorectal adenocarcinoma and have failed to respond to first-line oxaliplatin-based chemotherapy. A total of 524 patients are to be randomly assigned (1:1 ratio) to trifluridine/tipiracil plus bevacizumab or irinotecan, fluoropyrimidine and bevacizumab and stratified according to RAS status (wild type vs mutant). The primary endpoint of the phase II part is disease control rate with trifluridine/tipiracil plus bevacizumab therapy. Secondary endpoints are response rate and safety with trifluridine/tipiracil plus bevacizumab therapy. In the phase III part, the primary endpoint is overall survival, and secondary endpoints include quality of life, progression-free survival, response rate, disease control rate, safety, time to treatment failure, time to post-study treatment failure and the proportion of patients receiving post-study treatment. The first patient was enrolled in October 2017 and the study is anticipated to be completed in 2022. CLINICAL TRIAL REGISTRATION: JapicCTI-173618 (JapicCTI).

Genetic variation and haplotype structures of the glutathione S-transferase genes GSTA1 and GSTA2 in Japanese colorectal cancer patients.

Glutathione S-transferases (GSTs) play a vital role in the phase II biotransformation of many chemicals, including anticancer drugs. In this study, to elucidate the haplotype structures of the two closely related alpha-class genes GSTA1 and GSTA2, we screened for genetic variation in 214 Japanese colorectal cancer patients who received oxaliplatin-based chemotherapy. By direct resequencing of the 5'-flanking region, all the exons, and their flanking introns for 107 patients, 29 and 27 variants were identified in GSTA1 and GSTA2, respectively. The known functional single nucleotide polymorphisms (SNPs) -567T>G, -69C>T, and -52G>A in GSTA1*B were found at allele frequencies of 0.140. Of the four major GSTA2 allelic variants reported previously (GSTA2*A, *B, *C, and *E), only GSTA2*B (frequency = 0.154), *C (0.706), and *E (0.140) were detected. Following linkage disequilibrium analysis, haplotypes of both genes were separately estimated. Then, rapid genotyping methods for 7 and 6 SNPs tagging common haplotypes of GSTA1 and GSTA2, respectively, were developed using the single-base extension assay, and an additional 107 patients were genotyped. Finally, haplotype combinations of both genes were classified into 3 major types: GSTA1*A-GSTA2*C, GSTA1*A-GSTA2*B, and GSTA1*B-GSTA2*E. These findings will be useful in pharmacogenomic studies on xenobiotics including anticancer drugs.

Management of adjuvant S-1 therapy after curative resection of gastric cancer: dose reduction and treatment schedule modification.

BACKGROUND: The aim of this study was to determine the optimal management of adjuvant S-1 therapy for stage II or III gastric cancer, encompassing the details of dose reduction and treatment schedule modification. METHODS: We retrospectively examined 97 patients with stage II or III gastric cancer who received S-1 chemotherapy following gastrectomy between January 2003 and December 2007. S-1 (80 mg/m² per day) was orally administered twice daily for 4 weeks, followed by a 2-week rest. As a rule, treatment was continued for 1 year after gastrectomy. Dose reduction or treatment schedule modification was performed according to toxicity profiles. RESULTS: Among the 97 patients, 57 (59%) underwent dose reduction at least once and 39 (40%) received treatment schedule modification. Of the 57 patients who required dose reduction, 45 (79%) underwent reduction within 3 months of the beginning of treatment. The most common reasons for dose reduction were anorexia (47%), followed by diarrhea (32%), leukopenia (24%), and rash (16%), with the reasons overlapping. Although the difference in the requirement for dose reduction was not significant, patients with a low creatinine clearance level or those who underwent total gastrectomy had a greater tendency to require dose reduction. The duration of the S-1 treatment period was at least 3 months in 88% of the patients, at least 6 months in 82%, and the planned 1-year period in 73% of the patients. CONCLUSIONS: In most patients, the planned 1-year adjuvant S-1 therapy for stage II or III gastric cancer could be completed by modifying the dose reduction and treatment schedule.

Phase I study of NK012, a novel SN-38-incorporating micellar nanoparticle, in adult patients with solid tumors.

PURPOSE: We conducted a first-in-human phase I study to determine the dose-limiting toxicity (DLT), evaluate the pharmacokinetic profile, and document any antitumor activity of NK012, a novel SN-38-incorporating micellar nanoparticle. EXPERIMENTAL DESIGN: Patients with solid tumors refractory to standard therapy, or for which no standard therapy is available, were enrolled. NK012 was administered as a 30-minute infusion every 3 weeks. The starting dose was 2 mg/m(2) as SN-38 equivalent, and an accelerated titration schedule was used. Pharmacokinetic analysis was conducted in cycles 1 and 2. RESULTS: Twenty-four patients were enrolled in the study. No UGT1A1*28 homozygous patients were enrolled. Predominant toxicity was neutropenia. Nonhematologic toxicity, especially diarrhea, was mostly grade 1 or 2 during study treatments. Two of nine patients had DLT during cycle 1 at the 28 mg/m(2) dose level. DLTs were mostly neutropenia or a related event. Polymer-bound SN-38 (NK012) and SN-38 released from NK012 were slowly eliminated from the plasma, with a terminal-phase half-life of approximately 140 and 210 hours, respectively. Systemic exposure to both polymer-bound SN-38 and SN-38 increased in proportion to the dose. A refractory esophageal cancer patient and a lung carcinoid tumor patient had an objective response and continued the study treatment for 5 and 12 months, respectively. CONCLUSIONS: NK012 was well tolerated and showed antitumor activity including partial responses and several occurrences of prolonged stable disease across a variety of advanced refractory cancers. Phase II studies are ongoing.

Genetic polymorphisms of copper- and platinum drug-efflux transporters ATP7A and ATP7B in Japanese cancer patients.

ATP7A and ATP7B are involved in cellular resistance to platinum compounds such as cisplatin. By sequencing ATP7A, 38 genetic variations, including 30 novel ones were detected from 203 Japanese cancer patients. Of these, seven nonsynonymous variations were found: novel 1030A>G (R344G), 2111A>G (Q704R), 2200C>A (Q734K), 2948C>T (T983M) and 3112G>A (V1038I) at 0.004 frequencies and known 2299G>C (V767L) and 4390A>G (I1464V) at 0.351 and 0.075 frequencies, respectively. Regarding ATP7B, 28 novel and 33 known genetic variations were detected including 13 nonsynonymous ones: novel 1258A>G (M420V), 1426G>A (A476T), and 2401A>C (T801P) were found at 0.002, 0.005, and 0.002, respectively and known 1216G>T (A406S), 1366G>C (V456L), 2495A>G (K832R), 2785A>G (I929V), 2855G>A (R952K), 2871delC (P957PfsX9), 3419T>C (V1140A), 3836A>G (D1279G), 3886G>A (D1296N) and 3889G>A (V1297I) at 0.483, 0.463, 0.387, 0.005, 0.384, 0.005, 0.387, 0.002, 0.012, and 0.015 frequencies, respectively. Linkage disequilibrium between detected variations was also analyzed. Our results would provide fundamental and useful information for genotyping ATP7A and ATP7B in the Japanese and probably other Asian populations.

Combination chemotherapy with cisplatin and irinotecan in patients with adenocarcinoma of the small intestine.

BACKGROUND: Small-bowel adenocarcinoma (SBA) is a rare tumor that has a poor response to chemotherapy and a poor prognosis. Treatment strategies for SBA have not been clearly established. METHODS: All patients with SBA treated using a combination of cisplatin and irinotecan (IP) as first-line chemotherapy at the National Cancer Center Hospital in Japan between January 1999 and February 2007 were studied retrospectively. RESULTS: Eight patients received IP as first-line chemotherapy. The median follow-up was 9.5 months (range, 4.2-37.5 months). The median number of cycles of IP was three (range, 1-5). The overall response rate (complete or partial response) was 12.5% (complete response, n = 0; partial response, n = 1). The disease control rate (complete or partial response or stable disease) was 75%. The median time to treatment failure was 4.5 months (95% confidence interval, 0.9-5.8 months), and overall survival was 17.3 months (range, 1.9-21.3 months). The most common adverse events were neutropenia and anorexia. CONCLUSION: IP combination chemotherapy may be an acceptable option for patients with SBA. Further studies are warranted to determine the optimal chemotherapeutic regimen for SBA.