Discovery and development of trastuzumab deruxtecan and safety management for patients with HER2-positive gastric cancer

Approximately 12-15% of gastric cancers (GCs) are human epidermal growth factor receptor-2 (HER2)-positive (HER2 immunohistochemistry 3 + or 2 + /in situ hybridization + [ERBB2/CEP17 ≥ 2.0]). While the anti-HER2 monoclonal antibody trastuzumab, in combination with chemotherapy, is the standard treatment for HER2-positive GC, other HER2-targeted therapies have not demonstrated survival benefits in patients with GC, despite showing efficacy in patients with HER2-positive breast cancer. This indicates that there are unique challenges to the use of currently available HER2-targeted therapies for the treatment of HER2-positive GC. Trastuzumab deruxtecan (T-DXd) is an antibody-drug conjugate consisting of an anti-HER2 human monoclonal IgG1 antibody with the same amino acid sequence as trastuzumab, an enzymatically cleavable peptide-based linker, and DXd, a novel topoisomerase I inhibitor, as its released payload. T-DXd has a high drug-antibody ratio (approximately 8) and a demonstrated bystander antitumor effect. It has demonstrated significant efficacy when compared with standard therapies and is approved as third- or later-line treatment for HER2-positive GC in Japan and second- or later-line treatment in the US. T-DXd treatment is associated with gastrointestinal and hematological adverse events, and a risk of interstitial lung disease (ILD), with the ILD risk being higher in Japan than in countries other than Japan. However, most adverse events, including ILD, can be managed with proactive monitoring and T-DXd dose modification, and initiation of adequate treatment. In this review, we summarize the discovery and development of T-DXd and provide guidance for T-DXd safety management, including ILD monitoring, for patients with HER2-positive GC.

Safety and activity of trifluridine/tipiracil and ramucirumab in previously treated advanced gastric cancer: an open-label, single-arm, phase 2 trial

BACKGROUND

Findings of preclinical and clinical trials in colorectal cancer have shown promising antitumour effects of the co-formulation trifluridine/tipiracil and VEGF inhibition. We aimed to investigate the safety and activity of trifluridine/tipiracil and ramucirumab for previously treated advanced gastric cancer.

METHODS

We did an open-label, single-arm, two-cohort, phase 2 study at eight centres in Japan. We enrolled patients with unresectable advanced gastric cancer or gastro-oesophageal junction adenocarcinoma. Cohort A included patients previously treated with one line of chemotherapy without ramucirumab and cohort B included patients previously treated with two to four lines of chemotherapy, including ramucirumab. Patients received trifluridine/tipiracil (35 mg/m2) orally twice daily on days 1-5 and days 8-12 of each 28-day treatment cycle, plus intravenous ramucirumab (8 mg/kg) on days 1 and 15. The primary endpoint was the disease control rate, assessed by investigators and defined as the proportion of patients with a confirmed best overall response, according to Response Evaluation Criteria in Solid Tumors version 1.1. This trial is registered on JapicCTI (JapicCTI-194596) and is ongoing but not recruiting.

FINDINGS

Between April 8 and Oct 11, 2019, 64 patients were enrolled and included in the safety and activity analyses, 33 in cohort A and 31 in cohort B. In cohort A, the disease control rate was 85% (95% CI 68-95; 28 of 33 patients) and in cohort B it was 77% (59-90; 24 of 31 patients). Common treatment-related adverse events of grade 3 or worse were neutrophil count decreased (27 [82%] in cohort A and 23 [74%] in cohort B), white blood cell count decreased (eight [24%] and seven [23%]), and platelet count decreased (eight [24%] and four [13%]). Serious treatment-related adverse events were recorded in three patients in cohort A (fatigue and neutrophil count decreased; large intestine perforation; and febrile neutropenia, platelet count decreased, and anaemia). No patients in cohort B had a serious treatment-related adverse event, and no treatment-related deaths were reported in either cohort.

INTERPRETATION

Trifluridine/tipiracil and ramucirumab showed an acceptable safety profile and clinical activity in patients with previously treated advanced gastric cancer regardless of previous ramucirumab exposure.

FUNDING

Taiho Pharmaceutical and Eli Lilly.

Multicenter prospective trial of total gastrectomy versus proximal gastrectomy for upper third cT1 gastric cancer

BACKGROUND

The appropriate surgical procedure for patients with upper third early gastric cancer is controversial. We compared total gastrectomy (TG) with proximal gastrectomy (PG) in this patient population.

METHODS

A multicenter, non-randomized trial was conducted, with patients treated with PG or TG. We compared short- and long-term outcomes between these procedures.

RESULTS

Between 2009 and 2014, we enrolled 254 patients from 22 institutions; data from 252 were included in the analysis. These 252 patients were assigned to either the PG (n = 159) or TG (n = 93) group. Percentage of body weight loss (%BWL) at 1 year after surgery, i.e., the primary endpoint, in the PG group was significantly less than that of the TG group (- 12.8% versus - 16.9%; p = 0.0001). For short-term outcomes, operation time was significantly shorter for PG than TG (252 min versus 303 min; p < 0.0001), but there were no group-dependent differences in blood loss and postoperative complications. For long-term outcomes, incidence of reflux esophagitis in the PG group was significantly higher than that of the TG group (14.5% versus 5.4%; p = 0.02), while there were no differences in the incidence of anastomotic stenosis between the two (5.7% versus 5.4%; p = 0.92). Overall patient survival rates were similar between the two groups (3-year survival rates: 96% versus 92% in the PG and TG groups, respectively; p = 0.49).

CONCLUSIONS

Patients who underwent PG were better able to control weight loss without worsening the prognosis, relative to those in the TG group. Optimization of a reconstruction method to reduce reflux in PG patients will be important.

Confirmed three-year RFS and OS of the randomized trial of adjuvant S-1 versus S-1 plus docetaxel after curative resection of pStage III gastric cancer (JACCRO GC-07)

159

Background: JACCRO GC-07 is a randomized controlled trial to explore postoperative S-1/docetaxel compared to S-1 alone after D2 gastrectomy for pStage III gastric cancer (GC) patients. The second interim analysis demonstrated that the significant improvement of RFS was obtained by S-1/docetaxel compared to S-1 alone. The study was terminated by the recommendation of independent data and safety monitoring committee and the results were reported at ASCO 2018 and published in the Journal of Clinical Oncology (Yoshida K et al. 2019; 37:1296-1304). As 3 years have passed after completion of the enrollment, preplanned analysis was performed with the updated information of the patients. Methods: Patients with pStage III GC were randomly assigned to receive either S-1/docetaxel (S-1 80-120mg/body on days 1-14 with a 7-day rest followed by docetaxel 40mg/m2 on day 1 and S-1 80-120mg/body on days 1-14 every 21 days for 6 cycles followed by S-1 80-120mg/body on days 1-28 every 42 days for 4 cycles) or S-1 (80-120mg/body on days 1-28 every 42 days for 8 cycles) after D2 gastrectomy. Block randomization was performed by a central interactive computerized system stratified by the stage (IIIA, IIIB, IIIC) and histological type (differentiated or undifferentiated). The sample size of 1,100 was necessary to detect a 7% increase in the 3-year RFS. The primary endpoint was 3y RFS and the secondary endpoints were OS, TTF and safety. Results: In the present analysis, 400 recurrences and 324 deaths were confirmed among 912 patients during the median follow-up period of 42.5 months (0.3-85.16). The 3y RFS of 67.7% in the S-1/docetaxel group was significantly superior to 57.4% in the S-1 group (HR 0.715, 95% CI: 0.587-0.871, p = 0.0008) and the 3y OS was 77.7% in the S-1/docetaxel group and that of S-1 group was 71.2%, respectively (HR 0.742, 95% CI: 0.596-0.925, p = 0.0076), confirming the significant improving effect on the survival of the patient. Conclusions: Adjuvant S-1 plus docetaxel is recommended for patients with pStage III gastric cancer who underwent D2 gastrectomy without neoadjuvant chemotherapy. Clinical trial information: UMIN 000010337.

A phase II study of perioperative capecitabine plus oxaliplatin for clinical SS/SE N1-3 M0 gastric cancer (OGSG1601)

203

Background: D2 gastrectomy followed by adjuvant S-1 is one of the standard therapy for the patients (pts) with stage III gastric cancer (GC) in Japan; however, the outcome is not satisfactory. We examined the efficacy of perioperative capecitabine and oxaliplatin (CapeOx) in pts with clinical SS/SE N1-3 M0 GC. Methods: The eligibility criteria included histopathologically confirmed clinical T3(SS)/T4a(SE) N1-3 M0 GC according to the Japanese Classification of GC (JCGC; 3rd English Edition). Three cycles of neoadjuvant CapeOx (NAC; capecitabine, 2,000 mg/m2 for 14 days; oxaliplatin, 130 mg/m2 on day 1, every 3 weeks) were administered, followed by five cycles of adjuvant CapeOx after D2 gastrectomy. The primary endpoint was the pathological response rate (pRR) according to JCGC ( ≥Grade 1b). Results: Thirty-seven pts were enrolled from April 2016 to May 2017, and fully evaluated for efficacy and toxicity. Thirty-three pts (89.2%) completed the planned three cycles of NAC and underwent gastrectomy, with an R0 resection rate of 78.4% (n = 29) and a pRR of 54.1% (n = 20, p = .058; 90% confidence interval [CI], 39.4–68.2) were demonstrated. The relative dose intensity (RDI) of capecitabine and oxaliplatin were 90.5% and 91.9%, respectively. Among 27 pts who initiated AC, 21 (63.6%) completed the treatment, and the RDI of capecitabine and oxaliplatin were 80.9% and 65.1%, respectively. Grade 3–4 toxicities during NAC included neutropenia (8%), thrombocytopenia (8%), and anorexia (8%) and during AC included neutropenia (37%), diarrhea (4%), and anorexia (4%), but no treatment-related death was reported. The overall survival (OS) rate and relapse free survival (RFS) rate at 3 years was 83.8% (95% CI, 72.7-96.5%) and 73.0% (95% CI, 60.0-88.8%), respectively. Subgroup analyses according to residual tumor after surgery (R status) showed a 3-year OS and RFS rate of 86.2% (95% CI, 74.5-99.7%) and 75.7% (95% CI, 63.0-90.8%) for R0. Conclusions: Perioperative CapeOx showed good feasibility and favorable prognosis with sufficient pathological response, although statistical significance at .058 did not reach the commonly accepted cutoff of .05. The data obtained using this novel approach warrant further investigations. Clinical trial information: 000021641.

Survival analysis of a prospective multicenter observational study on surgical palliation among patients receiving treatment for malignant gastric outlet obstruction caused by incurable advanced gastric cancer

BACKGROUND

We had previously reported that surgical palliation could maintain quality of life (QOL) while improving solid food intake among patients with malignant gastric outlet obstruction (GOO) caused by advanced gastric cancer. The present study aimed to perform a survival analysis according to the patients' QOL to elucidate its impact on survival.

METHODS

Patients with GOO who underwent either palliative gastrectomy or gastrojejunostomy were included in this study. A validated QOL instrument (EQ-5D) was used to assess QOL at baseline and 2 weeks, 1 month, and 3 months following surgical palliation. Postoperative improvement in oral intake was also evaluated using the GOO scoring system (GOOSS). Thereafter, univariate and multivariate survival analyses were performed to determine independent prognostic factors.

RESULTS

The median survival time of the 104 patients included herein was 11.30 months. Patients who received postoperative chemotherapy, PS 0/1, baseline EQ-5D ≥ 0.75, improved or stable EQ-5D, and improved oral intake expressed as GOOSS = 3 had significantly better survival. Multivariate analysis identified postoperative chemotherapy, a better baseline PS, a better baseline EQ5D, improved or stable EQ5D scores, and improved oral intake 3 months after surgical palliation as independent prognostic factors.

CONCLUSION

Apart from preoperative PS and postoperative chemotherapy, the present study identified better baseline QOL, improvement in postoperative QOL, and improvement in oral intake as prognostic factors among patients who underwent palliative surgery for advanced gastric cancer with GOO.

Long-term results of a randomized controlled trial comparing neoadjuvant Adriamycin, cisplatin, and 5-fluorouracil vs docetaxel, cisplatin, and 5-fluorouracil followed by surgery for esophageal cancer (OGSG1003)

AIM

The aim is to report the long-term outcomes of preoperative cisplatin and fluorouracil plus docetaxel (DCF) vs Adriamycin (ACF) for resectable esophageal squamous cell carcinoma (ESCC). Previously, this trial showed that DCF is associated with prolonged recurrence-free survival (RFS).

METHODS

Patients were randomly assigned to two cycles of ACF (35 mg/m2 of Adriamycin, 70 mg/m2 of cisplatin intravenously on day 1, and 700 mg/m2 of fluorouracil infusion for 7 days) every 4 weeks or DCF (70 mg/m2 of docetaxel, 70 mg/m2 of cisplatin intravenously on day 1, and 700 mg/m2 of fluorouracil infusion for 5 days) every 3 weeks, followed by surgery. The primary endpoint was RFS. The secondary endpoint was overall survival (OS).

RESULTS

Between October 2011 and October 2013, 162 patients at 10 institutions were enrolled in the study, 162 of whom were eligible and randomly assigned to the two groups. The median follow-up for surviving patients was 69.8 months. The 5-year RFS was significantly better in the DCF group than in the ACF group (59.9% vs 40.7%, hazard ratio [HR] 0.55; 95% confidence interval [CI], 0.35-0.86; P = .009) and the 5-year OS was significantly better in the DCF group than in the ACF group (63.5% vs 49.4%, HR, 0.61; 95% CI, 0.38-0.96; P = .03). The benefit of DCF chemotherapy on survival was significantly greater in the subgroups with more advanced clinical T and N stage.

CONCLUSIONS

Cisplatin and fluorouracil plus docetaxel are associated with better RFS and OS than ACF in resectable ESCC patients.

[Questionnaire Survey of Third-Line Chemotherapy for Gastric Cancer in Yamaguchi Prefecture]

A questionnaire survey was conducted on third-line chemotherapy of unresectable or recurrent gastric cancer for 23 doctors involved in gastric cancer treatment in Yamaguchi prefecture. Eighty-seven% of doctors replied that third-line chemotherapy transfer rate was less than 60% of patients, and 13% of doctors replied that third-line chemotherapy transfer rate was more than 60% of patients. Nivolumab was the first-choice regimen for third-line chemotherapy, with 87% of doctors, 4% of doctors each for CPT-11, trifluridine/tipiracil hydrochloride, and docetaxel. Timing of switching from the second-line therapy to the third-line therapy, RECIST PD was the highest in 61% of doctors, with other baseline PD in 43% of doctors, clinical PD in 43% of doctors, and tumor marker elevation in 39% of doctors. The timing of regimen switching after using the immune checkpoint inhibitor was PD at the first CT in 43% of doctors, PD at the second CT in 43% of doctors. Nivolumab was used as the first-choice in more than 80% of the regimens for gastric cancer third-line chemotherapy in Yamaguchi prefecture. There was a difference in consciousness among doctors regarding the timing of switching from second- line to third-line chemotherapy and the timing of switching from nivolumab to fourth-line therapy.

Is it Necessary to Confirm Negative Margins in Gastrectomy for Peritoneal Lavage Cytology-positive Gastric Cancer?

BACKGROUND/AIM

The survival benefit of negative resection margins in patients who undergo gastrectomy with positive peritoneal lavage cytology (CY1) is unknown.

PATIENTS AND METHODS

We reviewed the medical records of 128 patients with CY1 but no other distant metastases who had undergone R1 gastrectomy, 21 of whom had positive margins. We compared overall survival (OS) according to margin status.

RESULTS

The positive-margin group had poorer performance status scores (p=0.02), higher number of patients had undergone limited lymphadenectomy (p=0.01), had type 4 tumors (p=0.01), and undifferentiated type (p=0.02). Median OS was 19.0 and 16.9 months in the groups with negative and positive margins, respectively (HR=1.26, 95%CI=0.75-2.12, p=0.39). An inverse probability of treatment weighted analysis showed an OS of 13.1 and 11.9 months for the groups with negative and positive margins, respectively (HR=0.83, 95%CI=0.43-1.63, p=0.59).

CONCLUSION

The prognoses of patients with CY1 and negative or positive margins may be equivalent.

A phase II trial of dose-reduced nab-paclitaxel for patients with previously treated, advanced or recurrent gastric cancer (OGSG 1302)

BACKGROUND

For unresectable or recurrent advanced gastric adenocarcinoma (AGC), tri-weekly administration of nanoparticle albumin-bound paclitaxel (nab-PTX) at 260 mg/m² achieved a response rate of 27.8% in a phase II trial in Japan. However, frequent neutropenia and peripheral neuropathy limit its use in clinical settings. We, thus, conducted a single-arm phase II trial to investigate the efficacy and safety of a reduced dose (220 mg/m²) of tri-weekly nab-PTX.

METHODS

Eligible patients included those with AGC and ECOG performance status of 0-2 who had received one or more prior chemotherapy containing fluoropyrimidine regimens. A reduced dose of nab-PTX (220 mg/m²) was administered tri-weekly. The primary endpoint was response rate (RR). Secondary endpoints were overall survival (OS), progression-free survival (PFS), disease-control rate (DCR), incidence of adverse events, relative dose intensity (RDI) and proportion of patients receiving subsequent chemotherapy.

RESULTS

Among 33 patients enrolled, 32 were treated with protocol therapy. RR was 3.1% [95% confidence interval (CI), 0-16.2%], which did not reach the protocol-specified threshold (p = 0.966). DCR was 37.5% (95% CI, 21.1-56.3%). Median OS and PFS were 6.3 (95% CI, 4.4-14.2) and 2.2 (95% CI, 1.8-3.1) months, respectively. RDI was 97.8%. Twenty (62.5%) patients received subsequent chemotherapy. Toxicity was relatively mild with the most common grade ≥ 3 adverse events being neutropenia (38%), anemia (13%), fatigue (19%), anorexia (16%), and peripheral neuropathy (13%).

CONCLUSION

Tri-weekly nab-PTX with a reduced dose (220 mg/m²) is not recommended for AGC in a second-line or later setting, despite demonstrating less toxicity than at 260 mg/m². Clinical trial registration The OGSG1302 trial was registered with UMIN-CTR as UMIN000000714.

Primary results of a randomized two-by-two factorial phase II trial comparing neoadjuvant chemotherapy with two and four courses of cisplatin/S-1 and docetaxel/cisplatin/S-1 as neoadjuvant chemotherapy for advanced gastric cancer

Aim

Neoadjuvant chemotherapy (NAC) is promising to improve the survival of resectable gastric cancer. However, suitable regimen and treatment duration for NAC have not yet been established.

Methods

We conducted a randomized phase II trial to compare two and four courses of neoadjuvant S-1/cisplatin (SC) and S-1/cisplatin/docetaxel(DCS) using a two-by-two factorial design for locally resectable advanced gastric cancer. Patients with M0 and either T4 or T3 in case of junctional cancer or scirrhous-type cancer received two or four courses of SC or DCS. Then, patients underwent D2 gastrectomy and adjuvant S-1 chemotherapy for 1 year. The primary endpoint was 3-year overall survival. The planned sample size was 120 eligible patients.

Results

Between October 2011 and September 2014, 132 patients were assigned to CS (n = 66; 33 in 2-courses and 33 in 4-courses) and DCS (n = 66; 33 in 2-courses and 33 in 4-courses). The 3-year OS was 58.1% in CS and 60.0% in DCS with hazard ratio of 0.80 (95% CI, 0.48-1.34), while it was 53.1% in the two courses and 65.0% in the four courses with hazard ratio of 0.72 (95% CI, 0.43-1.22). In the survival analysis by duration in each regimen, the 3-year OS was 58.1% for both two and four courses in CS, while it was 48.5% for two courses of DCS and 71.9% for four courses of DCS.

Conclusions

Considering high 3-year OS, four courses DCS has a value to be tested in a future phase III study to confirm superiority of neoadjuvant chemotherapy for locally advanced gastric cancer.

Comparison of S-1-cisplatin every 5 weeks with capecitabine-cisplatin every 3 weeks for HER2-negative gastric cancer (recurrent after S-1 adjuvant therapy or chemotherapy-naïve advanced): pooled analysis of HERBIS-2 (OGSG 1103) and HERBIS-4A (OGSG 1105) trials

BACKGROUND

We previously reported the HERBIS-4A phase II trial comparing S-1 plus cisplatin (SP) with capecitabine plus cisplatin (XP) in chemotherapy-naïve patients with HER2-negative advanced gastric cancer (GC). We performed a pooled analysis of HERBIS-4A and HERBIS-2, the phase II trial comparing SP with XP in HER2-negative recurrent GC patients with a recurrence-free interval after S-1 adjuvant therapy of ≥ 6 months.

PATIENTS AND METHODS

Patients were randomly assigned to receive either SP [S-1 (40-60 mg twice daily for 21 days) plus cisplatin (60 mg/m² on day 8), every 5 weeks] or XP [capecitabine (1000 mg/m² twice daily for 14 days) plus cisplatin (80 mg/m² on day 1), every 3 weeks].

RESULTS

In the pooled analysis, SP (n = 44-50) showed a longer progression-free survival [6.4 versus 5.1 months; hazard ratio (HR), 0.666; P = 0.062], overall survival (14.8 versus 10.6 months; HR, 0.695; P = 0.099), and time to treatment failure (4.6 versus 3.6 months; HR, 0.668; P = 0.045) as well as a higher disease control rate (86.4% versus 68.1%, P = 0.149) compared with XP (n = 47-51). A significant survival advantage for SP over XP was apparent in patients with a performance status of 0, a differentiated-type tumor histology, or a primary tumor localization to the upper portion of the stomach.

CONCLUSION

Our pooled analysis supports the use of SP in the first-line setting for patients with HER2-negative advanced or recurrent GC with a recurrence-free interval of ≥ 6 months.

CLINICAL TRIAL REGISTRATION

The HERBIS-2 trial was registered with UMIN-CTR as UMIN000006105.

Differences in disease status between patients with progression after first-line chemotherapy versus early relapse after adjuvant chemotherapy who undergo second-line chemotherapy for gastric cancer: Exploratory analysis of the randomized phase III TRICS trial

BACKGROUND

Second-line chemotherapy (SLC) improves survival in advanced gastric cancer (AGC). Patients receiving SLC are categorized into two disease status groups: tumour progression after first-line chemotherapy and early recurrence after adjuvant chemotherapy. Differences between these groups have not yet been clarified.

PATIENTS AND METHODS

A total of 163 eligible patients registered in the randomized phase III TRICS trial evaluating SLC for patients with AGC was classified into the progressive disease (PD) group (n = 55) or the early relapse (ER) group (n = 108). We compared overall survival (OS), progression-free survival (PFS), overall response rate (ORR), and safety. Adjusted OS and adjusted PFS were estimated using inverse probability of treatment weighting (IPTW).

RESULTS

The ER group had a lower median age than the PD group (66 vs. 72 years; P = 0.016), performance status (PS) 0 was more frequently seen in the ER group (87% vs. 71%; P = 0.012). The adjusted median OS was 13.7 months in the ER group and 13.6 months in the PD group (IPTW hazard ratio [HR]: 1.023; P = 0.854). The adjusted median PFS was 4.9 months in the ER group and 4.4 months in the PD group (IPTW HR: 0.707; P = 0.004). ORR was significantly better in the ER group than the PD group (21.3% vs. 4.9%; P = 0.020). No significant differences were observed in the incidence of adverse events.

CONCLUSIONS

ER was associated with improved PFS and better ORR than PD, although no difference in survival was demonstrated. From the viewpoint of treatment outcome, it seems appropriate to treat patients with ER in the same way as patients with PD.

CLINICAL TRIAL REGISTRATION

UMIN 000002571.

Impact of preoperative fecal short chain fatty acids on postoperative infectious complications in esophageal cancer patients

Background

The intestinal epithelial barrier allows absorption of dietary nutrients and prevents passage of pathogens and toxins into the body. Severe insults have a negative impact on the intestinal environment, which may decrease intestinal barrier function and cause bacterial translocation. Bacterial translocation, which can cause infectious complications, is defined as the passage of microbes from the gastrointestinal tract across the mucosal barrier to extraintestinal sites. The aim of this study was to investigate the correlation between concentrations of preoperative fecal organic acids and the occurrence of postoperative infectious complications in patients with esophageal cancer.

Methods

Fifty-five patients with esophageal cancer who underwent esophagectomy were enrolled in this study. Perioperative synbiotics were administered to all patients. Perioperative clinical characteristics and concentrations of preoperative fecal organic acids were compared between patients with and without postoperative infectious complications.

Results

Postoperative infectious complications occurred in 10 patients. In patients with complications, the concentrations of acetic acid and propionic acid were significantly lower than in patients without complications (p = 0.044 and 0.032, respectively). The concentration of butyric acid was nonsignificantly lower in patients with complications, while the concentration of lactic acid was nonsignificantly higher. The calculated gap between the concentrations of fecal acetic acid plus propionic acid plus butyric acid minus lactic acid was significantly lower in patients with complications. Multivariate analysis revealed that a low gap between acetic acid plus propionic acid plus butyric acid minus lactic acid was an independent risk factor for postoperative infectious complications (p = 0.027).

Conclusions

Preoperative fecal concentrations of organic acids had a clinically important impact on the occurrence of postoperative infectious complications in patients with esophageal cancer. To reduce postoperative infectious complications, it may be useful to modulate the intestinal environment and maintain concentrations of fecal organic acids before surgery.

DS-Screen: Prospective analysis of the expression status of FGFR2 and HER2 in colorectal and gastric cancer population

431

Background: FGFR2 and HER2 proteins are well-known molecular targets for cancer therapy, and there are emerging attractive protein-targeted agents such as second generation antibody-drug conjugates. However, there are still limited information about the expression status of FGFR2 and HER2 in gastrointestinal cancer and their relationship to patient background with cancer. In this study, expression status of FGFR2 and HER2 in advanced/metastatic gastric cancer (GC) and colorectal cancer (CRC) were prospectively analyzed in clinical setting. Moreover, eligible patients for the clinical trials of DS-1123 or DS-8201, which are FGFR2- or HER2-targeting anti-cancer agent respectively, were screened. Methods: Patients with advanced/metastatic GC, gastroesophageal junctional cancer (GEJ), and CRC were enrolled. Expression status of FGFR2 and HER2 were prospectively analyzed by IHC and/or FISH. Results: A total of 565 patients (GC; 160, GEJ; 16, CRC; 389) have been enrolled in this study from November 2016 to June 2018. FGFR2 expression (IHC 1+~3+) was observed in 24%, 44%, and 3% of GC, GEJ, and CRC respectively. HER2 expression (IHC 2+, 3+) was observed in 24%, 44%, and 17% of GC, GEJ, and CRC respectively. Expression levels of FGFR2 and HER2 seemed to be not correlated with each other in all 3 types of cancer. Distributions of expression level of FGFR2 or HER2 were slightly different among the histological types in GC. In CRC, distribution of HER2 expression level was also slightly different among the histological types and HER2 expression level was higher in KRAS/NRAS wild type compared to KRAS/NRAS mutant. There was no association between HER2 expression level and primary tumor sites in patients with CRC. Slight concordance of HER2 expression was observed between IHC and FISH in CRC. A total of 7 patients have been enrolled in clinical trials of DS-1123 or DS-8201 through this study based on the analysis findings. Conclusions: This study showed insights into the expression status of FGFR2 and HER2 in GC and CRC as a large-scale prospective analysis. Seven patients who had no standard therapy could access exploratory new drug based on targetable agents through this study. Clinical trial information: 163380.

Real-world efficacy and biomarker of nivolumab for advanced gastric cancer

388

Background: Although nivolumab demonstrated survival benefit and a manageable safety profile in previously-treated advanced gastric cancer in a phase III trial (ATTRACTION-2), the efficacy of nivolumab in real-world and predictive factors of responses to nivolumab for advanced gastric cancer remain unclear. We evaluated the efficacy of nivolumab and compared clinicopathological characteristics with responses to nivolumab and long-term survivals in patients with gastric cancer. Methods: 205 patients with unresectable or recurrent gastric cancer who were treated with nivolumab as 3rd or more line treatment were enrolled from 23 institutions. Tissue specimens were collected in 199 patients. PD-L1 expression of tumor specimens defined as tumor positive score (TPS) and combined positive score (CPS) and mismatch repair (MMR) were analyzed by immunohistochemistry. Tumor responses were assessed according to RECIST version 1.1. Hyper progressive disease (HPD) was defined as ≥two folds increase in tumor growth rate. Results: 138 out of 205 enrolled patients had measurable lesions. Response rate and HPD rate were 16.7% (23/138) and 22.0% (29/132), respectively. Response rate was significantly higher in patients with performance status (PS) 0-1, non-peritoneal diseases, CPS ≥10, and MMR deficient patients. On the other hand, PS 2-3 and liver metastases were predictive factors of HPD. Patients with CPS≥10 and MMR deficiency showed significantly better progression-free (P = 0.005, P = 0.001) and overall survivals (P = 0.005, P = 0.002). TPS showed no significant association with any outcomes. Conclusions: Real-world efficacy of nivolumab was shown in previously-treated advanced gastric cancer. CPS and MMR could be the useful biomarkers for the efficacy of nivolumab treatment as well as PS and metastasis site. Clinical trial information: UMIN000032164.

[A Case of Neuroendocrine Carcinoma Treated with Salvage Surgery after Systemic Chemotherapy]

A man in his 50s was admitted to our hospital due to hematemesis.Esophagogastroduodenoscopy revealed an 8 cm type 2 gastric tumor.The tumor was histologically diagnosed as a neuroendocrine carcinoma.CT showed that the tumor had directly infiltrated the liver but there was no distant metastasis.We performed open distal gastrectomy, D2 lymph node dissection, partial hepatectomy, and cholecystectomy.Four months after the surgery, metastases of the right adrenal gland and dorsal part of the inferior vena cava were found.Although a significant tumor reduction was obtained by 12 courses of chemotherapy with CDDP plus CPT-11, this effective treatment was discontinued for the patient's convenience.Fifteen months after the surgery, metastasis of the right adrenal gland and dorsal part of inferior vena cava demonstrated re-growth without any further metastasis.After 4 courses of the same regimen, a partial response was obtained for the recurrences.As a salvage surgery, we performed open right adrenal gland and the lymph nodes of dorsal of IVC resection.The patient is alive without recurrence 1 year after the salvage surgery.

A phase II trial of low-dose nab-paclitaxel for patients with previously treated or recurrent advanced gastric cancer (OGSG1302)

350

Background: Paclitaxel is a key drug in second-line chemotherapy for advanced or recurrent gastric cancer (AGC) and nanoparticle albumin-bound paclitaxel (nab-PTX) is also widely used in Japan. A previous phase II trial in Japan showed the effectiveness of nab-PTX (260 mg/m2) administered every 3 weeks (q3w) in patients with AGC with a response rate (RR) of 27.8%; however, toxicity was major concern with grade ≥3 neutropenia (49.1%) and peripheral neuropathy (23.6%). To solve this problem, we investigated the efficacy and safety of low-dose q3w nab-PTX regimen in AGC. Methods: Eligibility requirements included: aged ≥20 years, HER2-negative, histologically confirmed, unresectable or recurrent gastric adenocarcinoma, one or more prior chemotherapy containing fluoropyrimidine regimens, presence of measurable lesion(s) according to RECIST ver. 1.1, ECOG PS of 0–2, and adequate organ function. Nab-PTX was administered at a dose of 220 mg/m2 every 3 weeks. The primary endpoint was the RR. Secondary endpoints were overall survival (OS), progression-free survival (PFS), disease-control rate (DCR), incidence of adverse events, relative dose intensity and proportion of patients who received subsequent chemotherapy. Results: Thirty-three patients were enrolled from 10 institutions in Japan. Of the 32 patients treated with protocol therapy, RR (CR, PR) was 3.1% (95% CI, 0–16.2%), which was not reached the protocol-specified threshold (p = 0.966). DCR (CR, PR, SD) was 37.5% (95% CI, 21.1–56.3%), median OS and PFS were 6.3 months (95% CI, 4.4–14.2) and 2.2 months (95% CI, 1.8-3.1). Relative dose intensity was 97.8% (215 mg/m2). 62.5% of patients received subsequent chemotherapy. Most common grade ≥3 adverse events were neutropenia (38%), anemia (13%), fatigue (19%), anorexia (16%), and peripheral neuropathy (13%). Conclusions: Low-dose regimen of q3w nab-PTX was slightly less toxic, although it did not demonstrate the same effect as the original regimen in response rate. Therefore, it is not recommended for AGC in second or later line setting. Clinical trial information: UMIN 000012701.

Comparing five-weekly S-1 plus cisplatin with tri-weekly capecitabine plus cisplatin in patients with HER2-negative recurrent gastric cancer after S-1 adjuvant therapy or chemotherapy naïve advanced gastric cancer: A pooled analysis of HERBIS-2 (OGSG 1103) and HERBIS-4A (OGSG 1105) trials

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Background: HERBIS-2 trial was a phase II trial where S-1 plus cisplatin (SP) and capecitabine plus cisplatin (XP) were compared in recurrent HER2 negative gastric cancer (GC) patients with recurrence free interval (RFI) by S-1containing adjuvant of ≥ 6 months. We performed pooled analyses of HERBIS-2 and HERBIS-4A trial where SP and XP were compared in chemotherapy-naive HER2 negative gastric cancer (GC) patients as these trials being identical. Methods: Both HERBIS-2 and 4A trials, patients were randomly assigned to receive either SP (S-1 at 40–60 mg twice daily for 21 days plus cisplatin at 60 mg/ m2on day 8, every 5 weeks) or XP (capecitabine 1,000 mg/m2twice daily for 14 days plus cisplatin 80 mg/m2on day 1, every 3 weeks). Results: In HERBIS-2 which was s closed early due to poor accrual, SP ( N= 10) tended to confer a better overall survival (OS) compared with XP ( N= 9)[18.7 (95%CI, 2.8 – NR) months vs.13.4 (95% CI, 5.2 – 31.3) months; hazard ratio (HR), 0.443 (95% CI, 0.156 – 1.258); P= .117]. In pooled analyses with HERBIS-2 and 4A, SP ( N= 50) vs. XP ( N = 51) showed longer progression free survival (6.4 vs.5.1 months; HR, 0.666; P= .62), OS (14.8 vs. 10.6 months; HR, 0.695; P= .099), time to treatment failure (4.6 vs. 3.6 months; HR, 0.668; P= .045), and higher disease control rate (86.4% vs. 68.1%, P= .149). Subgroup analysis revealed that OS benefit in SP arm compared to XP arm was significantly larger if the patient having PS of 0 [HR, 0.554 (95% CI, 0.309 to 0.959; interaction P= .035], or the tumor arising from upper area of stomach [HR, 0.266 (95% CI, 0.070 to 0.731); interaction P= .013] or harboring differentiated type cancer [HR, 0.433 (95% CI, 0.228 to 0.822); interaction P= .011], respectively. Conclusions: Our data suggest the use of SP in the 1stline setting in HER2 negative advanced or recurrent GC with RFI by S-1 adjuvant of ≥ 6 months. Pooled analyses further suggest SP as the standard 1st line chemotherapy for HER2 negative AGC irrespective of S-1 adjuvant in Japan. Clinical trial information: UMIN000006755/UMIN000006105.

[A Case of Long-Term Disease Control after Administration of Oxaliplatin for Esophagogastric Junction Squamous Cell Carcinoma]

There are few reports of using oxaliplatin(L-OHP)for esophageal squamous cell carcinoma.We report a case of long-term disease control after administration of L-OHP for esophagogastric junction squamous cell carcinoma(EG).A woman in her 40s was diagnosed with EG(cT3, cN2, cM0, cStage Ⅲ).She received thoracoscopic, laparoscopic-assisted, subtotal esophagectomy with 3-field dissection after 3 courses of preoperative chemotherapy with DCF(docetaxel hydrate, cisplatin, 5- fluorouracil).Reconstruction was achieved using a retrosternally shifted gastric tube and transesophageal gastro-tubing. Pathological examination showed EG(ypT3, ypN2, ypM0, ypStage Ⅲ)(chemotherapy evaluation: Grade 1a).After 12 months, para-aortic lymph node recurrence(#112aoP, #16a2lat)was observed on a follow-up CT examination.First, we administered 5 courses of chemotherapy with SOX(S-1 100mg/m2 day 1-14 and L-OHP 100 mg/m2 day 1).Recurrent lymph nodes shrunk slightly, and there were no new lesions.Subsequently, there was no other adverse event except for Grade 1 chemotherapy-induced neuropathy.Second, we administered 3 courses of chemotherapy with FOLFOX(5-FU 400mg/m2, L-OHP 85mg/m2, Leucovorin 200 mg/m2 day 1, 5-FU 1,600mg/m2/46 hr)in combination with radiotherapy(total 60 Gy/ 30 Fr).Recurrent lymph nodes shrunk slightly, and there were no new lesions.Subsequently, there was no other adverse event except for Grade 1 chemotherapy-induced neuropathy.No new recurrence was observed 19 months after the first recur- rence.The patient continues to receive weekly nab-PTX(85mg/m2).A regimen that includes L-OHP is useful in the treatment of advanced or recurrent esophageal squamous cell carcinoma.

Efficacy and Safety of Trifluridine/Tipiracil Treatment in Patients With Metastatic Gastric Cancer Who Had Undergone Gastrectomy: Subgroup Analyses of a Randomized Clinical Trial

Question

Is trifluridine/tipiracil treatment safe and effective for the subpopulation of patients with previously treated metastatic gastric or gastroesophageal junction cancer who have undergone gastrectomy?

Findings

In this subgroup analysis of a randomized clinical trial, trifluridine/tipiracil treatment improved overall survival and progression-free survival compared with placebo among patients with previously treated metastatic gastric or gastroesophageal junction cancer and who had or had not undergone gastrectomy. No new safety concerns were reported, and hematologic toxic effects were more frequent among the subgroup who had undergone gastrectomy but were treated using dosing modifications.

Meaning

Trifluridine/tipiracil is a safe and effective treatment option for patients with pretreated metastatic gastric or gastroesophageal junction cancer regardless of previous gastrectomy.

Importance

Trifluridine/tipiracil (FTD/TPI) treatment has shown clinical benefit in patients with pretreated metastatic gastric cancer or gastroesophageal junction cancer (mGC/GEJC). Patients who have undergone gastrectomy constitute a significant proportion of patients with mGC/GEJC.

Objective

To assess the efficacy and safety of FTD/TPI among patients with previously treated mGC/GEJC who had or had not undergone gastrectomy.

Design, Setting, and Participants

This preplanned subgroup analysis of TAGS (TAS-102 Gastric Study), a phase 3, randomized, placebo-controlled, clinical trial included patients with mGC/GEJC who had received at least 2 previous chemotherapy regimens, and was conducted at 110 academic hospitals in 17 countries in Europe, Asia, and North America, with enrollment between February 24, 2016, and January 5, 2018; the data cutoff was March 31, 2018.

Interventions

Patients were randomized 2:1 to receive oral FTD/TPI 35 mg/m² twice daily or placebo twice daily with best supportive care on days 1 through 5 and days 8 through 12 of each 28-day treatment cycle.

Main Outcomes and Measures

The primary end point was overall survival. This subgroup analysis was conducted to examine potential trends and was not powered for statistical significance. Efficacy and safety end points were evaluated in the subgroups.

Results

Of 507 randomized patients (369 [72.8%] male; mean [SD] age, 62.5 [10.5] years), 221 (43.6%) had undergone gastrectomy (147 randomized to FTD/TPI and 74 to placebo) and 286 (56.4%) had not undergone gastrectomy (190 randomized to FTD/TPI and 96 to placebo). In the gastrectomy subgroup, the overall survival hazard ratio (HR) in the FTD/TPI group vs placebo group was 0.57 (95% CI, 0.41-0.79), and the progression-free survival HR was 0.48 (95% CI, 0.35-0.65). In the no gastrectomy subgroup, the overall survival HR in the FTD/TPI group vs placebo group was 0.80 (95% CI, 0.60-1.06), and the progression-free survival HR was 0.65 (95% CI, 0.49-0.85). Among FTD/TPI-treated patients, grade 3 or higher adverse events of any cause occurred in 122 of 145 patients (84.1%) in the gastrectomy subgroup and 145 of 190 (76.3%) in the no gastrectomy subgroup: 64 (44.1%) in the gastrectomy subgroup and 50 (26.3%) in the no gastrectomy subgroup had grade 3 or higher neutropenia, 31 (21.4%) in the gastrectomy subgroup and 33 (17.4%) in the no gastrectomy subgroup had grade 3 or higher anemia, and 21 (14.5%) in the gastrectomy subgroup and 10 (5.3%) in the no gastrectomy subgroup hD grade 3 or higher leukopenia. In the gastrectomy subgroup, 94 (64.8%) had dosing modifications because of adverse events vs 101 (53.2%) in the no gastrectomy subgroup; 15 (10.3%) in the gastrectomy group and 28 (14.7%) in the no gastrectomy group discontinued treatment because of adverse events. Treatment exposure was similar between groups.

Conclusions and Relevance

The FTD/TPI treatment was tolerable and provided efficacy benefits among patients with pretreated mGC/GEJC regardless of previous gastrectomy.

Trial Registration

ClinicalTrials.gov identifier: NCT02500043

Meta-analysis of two randomized phase III trials (TCOG GI-0801 and ECRIN TRICS) of biweekly irinotecan plus cisplatin versus irinotecan alone as second-line treatment for advanced gastric cancer

BACKGROUND

Biweekly irinotecan (CPT-11) plus cisplatin (CDDP) combination (BIRIP) and CPT-11 alone are both expectable options for treating advanced gastric cancer (AGC) in a second-line setting. We conducted a meta-analysis to compare the efficacy and safety of these two regimens in patients enrolled two randomized phase III trials.

PATIENTS AND METHODS

Individual patient-level data from two randomized phase III trials were collected for this study. In both trials, patients with AGC refractory to S-1-based chemotherapy were randomly allocated to BIRIP (CPT-11, 60 mg/m²; CDDP, 30 mg/m², q2w) or to CPT-11 (150 mg/m², q2w).

RESULTS

Cumulative data from 290 eligible patients were evaluated. The OS was 12.3 months [95% confidence interval (CI) 10.5-14.1] in the BIRIP group and 11.3 months (95% CI 10.0-13.2) in the CPT-11 group (hazard ratio 0.87; 95% CI 0.68-1.12, P = 0.272), while PFS was significantly longer in the BIRIP group (4.3 months [95% CI 3.5-5.1]) than in the CPT-11 group (3.3 months [2.9-4.1]; HR 0.77; 95% CI 0.61-0.98, P = 0.035). The response rate was 20.5% in the BIRIP group and 16.0% in the CPT-11 group (P = 0.361). However, the disease control rate was significantly better in the BIRIP group (72.1%) than in the CPT-11 group (59.2%) (P = 0.032). The two groups did not differ significantly in the incidences of grade 3 or worse adverse events.

CONCLUSIONS

Both BIRIP and CPT-11 may be good therapeutic options for patients with AGC as second-line treatment.

CLINICAL TRIAL REGISTRATION

UMIN 000025367.

[A Case of Pancreatic Head Cancer after Esophagectomy and Gastrectomy Treated with Pancreatoduodenectomy]

A woman in her 40s was hospitalizedfor jaundice. Six years before, she hadbeen diagnosedwith synchronous esophageal andgastric cancers andhadund ergone subtotal esophagectomy andtotal gastrectomy, accompaniedby reconstruction with the pedicled jejunum. Multimodal imaging revealed a tumor at the pancreatic head, probably pancreatic cancer, which induced severe stenosis of the intrapancreatic bile duct. Scraping cytology findings of the lesion via the percutaneous transhepatic cholangial drainage(PTCD)route strengthenedthe suspicion. In the image, although no obvious invasion of the major vessels or apparent distant metastases were detected, an abnormal shadow was found continuously lining the main tumor andpara -aortic region, which was a contraindication for curative resection. Therefore, we performed neoadjuvant chemotherapy with gemcitabine plus S-1. After 3 courses, the lesion size reduced notably, and pancreatoduodenectomy was performed. The pathological diagnosis was pancreatic cancer(ph, ypT3, ypN1a, ypM0, ypStage ⅡB). Except for pancreatic fistulas(Clavien-Dindo Ⅲa), the postoperative clinical course was uneventful, andshe was dischargedon postoperative day 27. To date, the patient is alive without recurrence and is undergoing adjuvant chemotherapy with S-1.

[Two Cases of Intraductal Papillary Neoplasm of the Bile Duct(IPNB)Resected with Hepatectomy]

Case 1: A man in his 70s was referred to our hospital for further examination of a liver tumor(S3, 3 cm)detected by ultrasonography. Multimodal image examination showed a cystic lesion with solid papillary components located in the S4 accompanied by dilatation of the surrounding intrahepatic bile duct. Although biliary cytology did not indicate confirmed malignancy, the lesion was thought to be an intraductal papillary neoplasm of bile duct(IPNB)with malignant potential, and a left lobectomy was performed. Histopathological examination revealed a papillary tumor in the intrahepatic bile duct which consisted of atypical epithelial cells of pancreatobiliary type, and the lesion was diagnosed as an IPNB with high-grade intraepithelial neoplasia. Case 2: A woman in her 70s was referred to our hospital because of a liver tumor(S4, 8 cm)detected by ultrasonography. Multimodal image examination showed a cystic lesion localized to the liver(S3, 8 cm), and endoscopic retrograde cholangiopancreatography(ERCP)showed continuity of the cyst and the intrahepatic bile duct. The biliary cytology was positive, and the lesion was thought to be a malignant IPNB. After preoperative drainage of the cystic lesion, a left lobectomy was conducted. Histopathological examination showed that the papillary tumor localized to the bile duct and atypical epithelium cells of pancreatobiliary type were infiltrating into the surrounding matrix. We diagnosed this tumor as an IPNB with an associated invasive carcinoma.

[A Case of Lymph Node Recurrence with Invasion to the Trachea after the Resection of Esophageal Cancer Treated by Multidisciplinary Treatment]

A 78-year-old man who underwent esophagectomy for middle thoracic esophageal squamous cell carcinoma(pT1bN0M0, pStage Ⅰ)was diagnosed with lymph node recurrence 12 months after the initial surgery. He received chemoradiotherapy(5- fluorouracil plus cisplatin); however, the treatment was terminated at the middle of the treatment course because of progressive disease. He received chemotherapy(docetaxel plus 5-fluorouracil plus cisplatin)as a second-line treatment, which was also canceled due to serious adverse events. Partial response was achieved after the second therapy; therefore, surgical excision was performed. Thirteen months after the second surgery, he was diagnosed with second local recurrence with invasion to the trachea. Another course of chemotherapy(docetaxel[2-weekly]plus 5-fluorouracil plus cisplatin)was administered, which also achieved a partial response. Thus, surgical excision with partial tracheal resection and mediastinal tracheostomy was performed. He has been alive without recurrence for 6 months after the final operation. In case of postoperative solitary lymph node recurrence of esophageal cancer, long-term survival can be expected with multidisciplinary treatment.