Yasutoshi Kuboki

Comprehensive analyses using next-generation sequencing and immunohistochemistry enable precise treatment in advanced gastric cancer

BACKGROUND In advanced gastric cancer (AGC), most clinical trials are designed on the basis of protein expression or gene amplification of specific genes. Recently, next-generation sequencing (NGS) allowed us to comprehensively profile the tumor gene status. This study aimed to elucidate the profiling between gene alterations and protein expression in AGC to aid in future clinical trials on AGC. PATIENTS AND METHODS Formalin-fixed, paraffin-embedded tumor samples from 121 stage III/IV gastric cancer patients were examined for protein expression of tyrosine kinase receptors (RTKs; ERBB2, EGFR, c-MET, and FGFR2) using immunohistochemistry (IHC). Furthermore, 409 cancer-related genes were sequenced to detect mutations and copy number variations using NGS. RESULTS Most ERBB2 overexpression (IHC 3+) cases (80.0%) had ERBB2 amplification and did not have other RTK amplification or oncogene mutations. However, one-fourth of MET overexpression cases (25.0%) had ERBB2 alterations. EGFR and FGFR2 overexpression cases had ERBB2 alterations or other gene alterations such as KRAS or PIK3CA. On the other hand, most of the four RTK amplification cases (88.2%) were mutually exclusive with each amplification. However, RTK amplification did not simply correlate with protein overexpression, whereas cases with RTK high-level amplification had protein overexpression and rarely showed other co-existing gene alterations. CONCLUSION AGC involves a complicated arrangement of protein expression and gene alterations. Comprehensive analyses of NGS and IHC will be necessary to design the optimal therapy for treating the appropriate population of patients in future clinical trials.

TAS-102 plus bevacizumab for patients with metastatic colorectal cancer refractory to standard therapies (C-TASK FORCE): an investigator-initiated, open-label, single-arm, multicentre, phase 1/2 study

BACKGROUND In patients with heavily treated metastatic colorectal cancer, TAS-102-a combination of trifluridine and tipiracil-has shown a significant overall survival benefit compared with placebo. In preclinical models, TAS-102 plus bevacizumab has shown enhanced activity against colorectal cancer xenografts compared with that for either drug alone. In this phase 1/2 study, we assessed the activity and safety of TAS-102 plus bevacizumab. METHODS We did this investigator-initiated, open-label, single-arm, multicentre, phase 1/2 trial of TAS-102 plus bevacizumab in four cancer centres in Japan. Eligible patients were aged 20 years or older; had histologically confirmed unresectable, metastatic colorectal adenocarcinoma; were refractory or intolerant to fluoropyrimidine, irinotecan, oxaliplatin, anti-VEGF therapy, and anti-EGFR therapy (for tumours with wild-type KRAS); and had no previous treatment with regorafenib. Patients had to have an Eastern Cooperative Oncology Group performance status of 0 or 1. Using a dose de-escalation design in phase 1, the recommended phase 2 dose (RP2D) was determined for TAS-102 (35 mg/m2 given orally twice daily on days 1-5 and 8-12 in a 28-day cycle for level 1) plus bevacizumab (5 mg/kg, administered by intravenous infusion for 30 min every 2 weeks). In phase 2, patients received the RP2D. The primary endpoint was centrally assessed progression-free survival at 16 weeks, analysed in the first 21 patients to be enrolled and treated with the RP2D who had at least one imaging assessment. This study is completed and registered with the University Hospital Medical Information Network, number UMIN000012883. FINDINGS Between Feb 25, 2014, and July 23, 2014, we enrolled 25 patients with metastatic colorectal cancer: six patients in phase 1 and 19 patients in phase 2. The six patients who received TAS-102 at level 1 experienced no dose-limiting toxicities and this was deemed the RP2D. Nine of 21 patients who received the RP2D did not have a centrally assessed progression event; 16-week progression-free survival was 42·9% (80% CI 27·8-59·0). The most common grade 3 or worse adverse events as assessed in all 25 patients were neutropenia (18 [72%] patients), leucopenia (11 [44%]), anaemia (four [16%]), febrile neutropenia (four [16%]), and thrombocytopenia (three [12%]). Treatment-related serious adverse events were reported in three (12%) patients. No treatment-related deaths occurred. INTERPRETATION TAS-102 plus bevacizumab has promising activity with manageable safety, suggesting that this combination might become a potential treatment option for patients with metastatic colorectal cancer in a refractory setting. FUNDING Taiho Pharmaceutical.

R-CHOP with dose-attenuated radiation therapy could induce good prognosis in gastric diffuse large B cell lymphoma

BackgroundThe treatment strategy for gastric diffuse large cell lymphoma (DLBCL) has not been standardized in such as to the cycles of chemotherapy, dose of radiation, or necessity for the surgery. Although the results of CHOP or R-CHOP treatments have demonstrated the good prognosis, the treatments have been controversial in many cases.MethodsWe retrospectively analyzed 40 gastric DLBCL patients receiving chemotherapy with or without radiation in our institute. Those in stages II-IV were treated with six cycles of R-CHOP without radiation; for those in stage I, we administered three cycles of R-CHOP with radiation.ResultsThe three-year overall survival (OS) and progression-free survival (PFS) rates were 95.2 and 91.8%, respectively. Those in stage I obtained 100% of OS. The radiation dose prescribed was 30.6 Gy for CR cases and 39.6 to 40 Gy for PR after chemotherapy. Although survival rates tended to correlate with staging groups or age-adjusted IPI classifications, multivariate statistical analysis did not show clear differences. All 14 patients with initial bleeding were successfully managed without surgery during treatment.ConclusionR-CHOP therapy was very effective for gastric DLBCL. It may be not necessary to use more than 30.6 Gy of radiotherapy in the highly chemo-sensitive cases. Less toxic treatments should be made available to gastric DLBCL patients.

Safety, pharmacokinetics, and antitumour activity of trastuzumab deruxtecan (DS-8201), a HER2-targeting antibody–drug conjugate, in patients with advanced breast and gastric or gastro-oesophageal tumours: a phase 1 dose-escalation study

BACKGROUND Antibody-drug conjugates have emerged as a powerful strategy in cancer therapy and combine the ability of monoclonal antibodies to specifically target tumour cells with the highly potent killing activity of drugs with payloads too toxic for systemic administration. Trastuzumab deruxtecan (also known as DS-8201) is an antibody-drug conjugate comprised of a humanised antibody against HER2, a novel enzyme-cleavable linker, and a topoisomerase I inhibitor payload. We assessed its safety and tolerability in patients with advanced breast and gastric or gastro-oesophageal tumours. METHODS This was an open-label, dose-escalation phase 1 trial done at two study sites in Japan. Eligible patients were at least 20 years old with breast or gastric or gastro-oesophageal carcinomas refractory to standard therapy regardless of HER2 status. Participants received initial intravenous doses of trastuzumab deruxtecan from 0·8 to 8·0 mg/kg and dose-limiting toxicities were assessed over a 21-day cycle; thereafter, dose reductions were implemented as needed and patients were treated once every 3 weeks until they had unacceptable toxic effects or their disease progressed. Primary endpoints included identification of safety and the maximum tolerated dose or recommended phase 2 dosing and were analysed in all participants who received at least one dose of study drug. The dose-escalation study is the first part of a two-part study with the second dose-expansion part ongoing and enrolling patients as of July 8, 2017, in Japan and the USA. This trial is registered at ClinicalTrials.gov, number NCT02564900. FINDINGS Between Aug 28, 2015, and Aug 26, 2016, 24 patients were enrolled and received trastuzumab deruxtecan (n=3 for each of 0·8, 1·6, 3·2, and 8·0 mg/kg doses; n=6 for each of 5·4 and 6·4 mg/kg). Up to the study cutoff date of Feb 1, 2017, no dose-limiting toxic effects, substantial cardiovascular toxic effects, or deaths occurred. One patient was removed from the activity analysis because they had insufficient target lesions for analysis. The most common grade 3 adverse events were decreased lymphocyte (n=3) and decreased neutrophil count (n=2); and grade 4 anaemia was reported by one patient. Three serious adverse events-febrile neutropenia, intestinal perforation, and cholangitis-were reported by one patient each. Overall, in 23 evaluable patients, including six patients with low HER2-expressing tumours, ten patients achieved an objective response (43%, 95% CI 23·2-65·5). Disease control was achieved in 21 (91%; 95% CI 72·0-98·9) of 23 patients. Median follow-up time was 6·7 months (IQR 4·4-10·2), with nine (90%) of ten responses seen at doses of 5·4 mg/kg or greater. INTERPRETATION The maximum tolerated dose of trastuzumab deruxtecan was not reached. In this small, heavily pretreated study population, trastuzumab deruxtecan showed antitumour activity, even in low HER2-expressing tumours. Based on safety and activity, the most likely recommended phase 2 dosing is 5·4 or 6·4 mg/kg. FUNDING Daiichi Sankyo Co, Ltd.

Prognostic and Predictive Value of HER2 Amplification in Patients With Metastatic Colorectal Cancer

Micro‐Abstract: We evaluated the prognostic impact of human epidermal growth factor receptor 2 (HER2) amplification in metastatic colorectal cancer as well as the efficacy of anti–epidermal growth factor receptor (EGFR) therapy. HER2 amplification was as potentially prognostic for overall survival as RAS or BRAFV600E mutation as well as a potential negative predictive factor of anti‐EGFR therapy in metastatic colorectal cancer. Purpose: To evaluate a prognostic and predictive value of HER2 amplification in patients with metastatic colorectal cancer (mCRC). Patients and Methods: Patients with mCRC who underwent surgical resection of the primary tumor and who received best supportive care with or without palliative chemotherapy between 2005 and 2015 were included. HER2 immunohistochemistry was performed using formalin‐fixed, paraffin‐embedded primary tumor specimens. HER2 amplification was confirmed by fluorescence in‐situ hybridization. The RAS and BRAFV600E mutations were centrally assessed using a PCR‐based method. Patients were divided into 4 subgroups: R (RAS mutant), B (BRAFV600E mutant), H (wild‐type RAS/BRAF with HER2 amplification), and W (wild‐type RAS/BRAF without HER2 amplification). Overall survival (OS) and progression‐free survival of anti–epidermal growth factor receptor (EGFR) therapy were assessed. Results: Among 370 eligible patients, data of 359 were successfully analyzed. Fifteen tumors harbored HER2 amplifications, including 4 tumors with concomitant RAS mutation (group R). The number of patients in groups R, B, H, and W was 204, 13, 11, and 131, respectively. The median OS was 27.4 months, and the median follow‐up time was 63.2 months. The median OS for groups R, B, H, and W was 24.0, 14.2, 19.9, and 39.1 months, respectively. The number of patients who received anti‐EGFR therapy in groups R, B, H, and W was 17, 4, 5, and 49, respectively. Progression‐free survival of anti‐EGFR therapy was significantly shorter in groups R, B, and H than in group W. Conclusion: HER2 amplification was predictive of anti‐EGFR therapy response and appeared to be prognostic in mCRC patients.

Prophylactic Use of Oral Dexamethasone to Alleviate Fatigue During Regorafenib Treatment for Patients With Metastatic Colorectal Cancer

Micro‐Abstract Fatigue is the most common toxicity of all grade‐associated toxicities associated with regorafenib for the treatment for colorectal cancer. A retrospective study was performed to clarify the safety and efficacy of prophylactic oral dexamethasone on fatigue. Our data suggest that the prophylactic use of dexamethasone reduced the incidence of fatigue during regorafenib therapy. Background: Fatigue is the most common toxicity of all grade toxicities with regorafenib, was the second most common toxicity in the CORRECT (regorafenib monotherapy for previously treated metastatic colorectal cancer) study, and is a major reason for early dose modification. The results from a recent randomized study suggested that dexamethasone (DEX) can improve cancer‐related fatigue. Patients and Methods: We retrospectively analyzed the effect of prophylactic use of an oral DEX on fatigue during regorafenib treatment in patients with metastatic colorectal cancer (mCRC). A total of 105 patients who had received regorafenib at our institution from May 2013 to August 2014 were divided into 2 groups according to oral DEX use (2 mg/day; at the physicians discretion). Results: Of the 105 patients, 31 received prophylactic DEX and 74 received regorafenib alone. The time to dose modification was significantly longer in the DEX group than in the no DEX group (15 days vs. 9 days; P = .009). The incidence of fatigue (grade ≥ 1) was significantly lower with DEX than without DEX (25.8% vs. 50.0%; P = .022). Fewer patients experienced a decreased appetite (grade ≥ 1; 3.2% vs. 35.1%; P < .001) and hand–foot skin reaction (HFSR; grade ≥ 3; 3.2% vs. 25.7%, P = .002) with DEX than without DEX. Conclusion: DEX was effective in reducing fatigue during regorafenib treatment, resulting in prolonging the time to dose modification for regorafenib. The decreased incidence of appetite loss and HFSR also suggest that concurrent DEX administration with regorafenib warrants further investigation.

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

TPS3623Background: Immune checkpoint inhibitor (ICI) was reported to show durable responses in patients with MSI-H (Microsatellite Instability-High) metastatic colorectal cancer (mCRC). On the othe...

How do we apply adjuvant FOLFOX to Japanese patients with curatively resected colorectal cancer

Aim:  In Japan the combination of fluorouracil (5‐FU), leucovorin and oxaliplatin (FOLFOX) was approved as adjuvant therapy for stage III or high‐risk stage II colon cancer only in September 2009. In this study we evaluated the safety and efficacy of FOLFOX as adjuvant chemotherapy for stage IIIb or IV colorectal cancer (CRC) patients in a Japanese group at a single institute.

Feasibility study of cancer genome alterations identified by next generation sequencing: ABC study

We confirmed the feasibility of NGS-based amplicon sequencing using biopsy samples, making the basis for nationwide genome screening for cancer patients using biopsy samples.

Clinicopathological features of 22C3 PD-L1 expression with mismatch repair, Epstein–Barr virus status, and cancer genome alterations in metastatic gastric cancer

BackgroundRecently, the U.S. Food and Drug Administration approved pembrolizumab for patients (pts) with PD-L1-positive metastatic gastric cancer (MGC) based on 22C3 immunohistochemistry (IHC) assay. However, little is known about detailed clinicopathological features of 22C3 PD-L1 expression in MGC.Patients and methodsPts with histologically confirmed MGC were eligible for this prospective observational study. PD-L1 expression (22C3) on tumor cell (TC) or immune cell (IC) and mismatch repair (MMR) were analyzed by IHC. Epstein–Barr virus (EBV) was detected by in situ hybridization. The expressions of tyrosine kinase receptors (RTKs) and cancer genome alterations were evaluated by IHC or next-generation sequencing.ResultsA total of 225 pts were analyzed in this study. PD-L1 expression on TC, PD-L1 on IC, MMR-deficient (D-MMR), and EBV positivity were identified in 8.4, 65.3, 6.2, and 6.2% cases, respectively. PD-L1 expression in TC was more frequently observed in pts with D-MMR (P < 0.001), PIK3CA mutation (P = 0.020), and KRAS mutation (P = 0.002), and PD-L1 on IC was associated with EBV positivity (P = 0.034), and lymph-node metastasis (P < 0.001). PD-L1 expression on either IC or TC was less frequently observed in pts with peritoneal metastasis and Borrmann Type 4. A significant association was not observed between PD-L1 expression and RTKs expression or presence of other gene alterations. PD-L1 expression on either TC or IC was not prognostic factor.Conclusions22C3 PD-L1 expression in MGC was associated with distinct clinicopathological features, but was not a prognostic factor.