Quantitative Analysis of the Concentration of Trifluridine in Tumor Hypoxic Regions Using a Novel Platform Combining Functional Endoscopy and Mass Spectrometry.

Hypoxic regions in solid tumors are highly resistant to drugs and thus represents an obstacle in drug discovery. Currently, however, there are technical barriers in sampling human hypoxic tumors and examining drug delivery with high sensitivity and accuracy. Herein, we present a new platform combining functional endoscopy and highly sensitive liquid chromatography-mass spectrometry (LC-MS) to assess drug delivery to hypoxic regions. Because oxygen saturation endoscopic imaging (OXEI), a functional endoscopy, can evaluate lesions and hypoxia in real-time by simultaneously acquiring a pseudocolor map of oxygen saturation and conventional endoscopic images, this platform can be used to evaluate drug delivery with human samples from hypoxic regions. As the first clinical application of this platform, the relationship between hypoxic regions and the concentration of trifluridine (FTD) incorporated into DNA was evaluated in patients with advanced gastric cancer treated with FTD/tipiracil (FTD/TPI; n = 13) by obtaining and analysis of tissue samples by OXEI and LC-MS and vascular maturity index by CD31/α-SMA staining ex vivo. The results showed that the concentration of FTD was significantly higher in the normoxic region than in the hypoxic region (P < 0.05) and there were significantly more immature vessels in hypoxic regions than in normoxic regions (P < 0.05). These results indicate that the platform was sufficiently sensitive to evaluate differences in drug anabolism in different oxygenic regions of human tumor tissue. This new platform allows quantitative drug analysis in hypoxic regions and is expected to initiate a new era of drug discovery and development.

Special Issue: Evaluation of the Antitumor Mechanism of Armed Antibodies.

This Special Issue focuses on the use of therapeutic antibodies in vitro, in vivo, and in clinical studies [...].

p70S6K/Akt dual inhibitor DIACC3010 is efficacious in preclinical models of gastric cancer alone and in combination with trastuzumab.

The PI3K-Akt-mTOR (PAM) pathway is implicated in tumor progression in many tumor types, including metastatic gastric cancer (GC). The initial promise of PAM inhibitors has been unrealized in the clinic, presumably due, in part, to the up-regulation of Akt signaling that occurs when the pathway is inhibited. Here we present that DIACC3010 (formerly M2698), an inhibitor of two nodes in the PAM pathway, p70S6K and Akt 1/3, blocks the pathway in in vitro and in vivo preclinical models of GC while providing a mechanism that inhibits signaling from subsequent Akt up-regulation. Utilizing GC cell lines and xenograft models, we identified potential markers of DIACC3010-sensitivity in Her2-negative tumors, i.e., PIK3CA mutations, low basal pERK, and a group of differentially expressed genes (DEGs). The combination of DIACC3010 and trastuzumab was evaluated in Her2-positive cell lines and models. Potential biomarkers for the synergistic efficacy of the combination of DIACC3010 + trastuzumab also included DEGs as well as a lack of up-regulation of pERK. Of 27 GC patient-derived xenograft (PDX) models tested in BALB/c nu/nu mice, 59% were sensitive to DIACC3010 + trastuzumab. Of the 21 HER2-negative PDX models, DIACC3010 significantly inhibited the growth of 38%. Altogether, these results provide a path forward to validate the potential biomarkers of DIACC3010 sensitivity in GC and support clinical evaluation of DIACC3010 monotherapy and combination with trastuzumab in patients with HER2- negative and positive advanced GCs, respectively.

Quantitative analysis of drug distribution in heterogeneous tissues using dual-stacking capillary electrophoresis-mass spectrometry.

BACKGROUND AND PURPOSE: Intratumour heterogeneity frequently leads to drug resistance, which is a major issue in drug discovery. Drug distribution is one of the key factors for elucidating the resistance mechanism; however, quantitative and regional drug measurement is challenging. Here, we developed a novel ultra-sensitive analytical method and applied it to HER3-targeting antibody-drug conjugate patritumab deruxtecan (HER3-DXd), aiming to explore its payload (DXd) distribution within heterogeneous tissues. EXPERIMENTAL APPROACH: The developed analytical method is named LDMS-CE-MS, a capillary electrophoresis-mass spectrometry (CE-MS) coupled with a novel sample preconcentration/separation method called "large-volume dual-sample stacking by micelle collapse and sweeping (LDMS)". First, the analytical performance of LDMS-CE-MS for DXd detection was evaluated. Subsequently, we evaluated the bystander effect of HER3-DXd, where tumour tissues were excised from xenograft models and clinical specimens after administration of HER3-DXd. HER3-high expression, adjacent, and HER3-low expression regions were then sampled by laser microdissection to quantify the released DXd. KEY RESULTS: LDMS concentrated DXd by 1000-fold and separated it from the hydrophilic bio-matrix through continuous capture and release by the charged micelles, allowing quantification at sub-attomole-level. DXd concentrations decreased in the order of antigen-high expression > adjacent > antigen-low expression regions in the tumour xenograft model, whereas in clinical specimens, adjacent and antigen-high expression regions had approximately the same concentration. These distributions represent a bystander effect. CONCLUSIONS AND IMPLICATIONS: Our LDMS-CE-MS successfully visualized the attomole-level drug distributions in heterogeneous clinical specimens. This new platform opens a new era of quantitative pharmacokinetic analysis, facilitating drug discovery and development.

Safety, Tolerability, and Pharmacokinetics of TAK-931, a Cell Division Cycle 7 Inhibitor, in Patients with Advanced Solid Tumors: A Phase I First-in-Human Study.

Purpose: We conducted a first-in-human, dose-escalation study, to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and activity of TAK-931, a cell division cycle 7 inhibitor, in Japanese patients with advanced solid tumors. Experimental Design: Patients ages ≥20 years received oral TAK-931: once daily for 14 days in 21-day cycles (schedule A; from 30 mg); once daily or twice daily for 7 days on, 7 days off in 28-day cycles (schedule B; from 60 mg); continuous once daily (schedule D; from 20 mg); or once daily for 2 days on, 5 days off (schedule E; from 100 mg) in 21-day cycles. Results: Of the 80 patients enrolled, all had prior systemic treatment and 86% had stage IV disease. In schedule A, 2 patients experienced dose-limiting toxicities (DLTs) of grade 4 neutropenia and the maximum tolerated dose (MTD) was 50 mg. In schedule B, 4 patients experienced DLTs of grade 3 febrile neutropenia (n = 3) or grade 4 neutropenia (n = 1); the MTD was 100 mg. Schedules D and E were discontinued before MTD determination. The most common adverse events were nausea (60%) and neutropenia (56%). Time to maximum plasma concentration of TAK-931 was approximately 1-4 hours postdose; systemic exposure was approximately dose proportional. Posttreatment pharmacodynamic effects correlating to drug exposure were observed. Overall, 5 patients achieved a partial response. Conclusions: TAK-931 was tolerable with a manageable safety profile. TAK-931 50 mg once daily days 1-14 in 21-day cycles was selected as a recommended phase II dose and achieved proof of mechanism. Trial registration ID: NCT02699749. Significance: This was the first-in-human study of the CDC7 inhibitor, TAK-931, in patients with solid tumors. TAK-931 was generally tolerable with a manageable safety profile. The recommend phase II dose was determined to be TAK-931 50 mg administered once daily on days 1-14 of each 21-day cycle. A phase II study is ongoing to confirm the safety, tolerability, and antitumor activity of TAK-931 in patients with metastatic solid tumors.

[New Armed Antibody"ADC: Antibody-Drug Conjugate"for Solid Tumor].

Armed antibodies, of which are representative antibody-drug conjugate(ADC)and radioimmunotherapy(RIT), are attracting attention as next-generation antibody drugs with high efficacy and low side effects. Armed antibodies require clinically optimized adaptation and development strategies, in addition to the fusion of basic technologies such as organic chemistry, protein chemistry, imaging technology, structural biology, and biomarker research. In armed antibodies, the antibody is only a carrier for deliver and its therapeutic effect affects the specificity/strength of the payload, which is the effector agent for target molecules on cell surface. An ADC with a bystander effect is a promising drug for solid tumors with heterogeneous target molecule expression. Aside from the next-generation ADC DS8201, new ADCs are being developed at an accelerated pace, demonstrating new therapeutic possibilities. In the future, it will be necessary to optimize predictors of therapeutic effect based on the MOA of ADC.

Antibody-drug conjugates to treat gastric cancer.

INTRODUCTION: Despite new treatment options, the long-term prognosis of recurrent or inoperable gastric cancer remains poor. Antibody-drug conjugates (ADCs) are a new class of drugs and have shown promising results in clinical trials. AREAS COVERED: This review focuses on recent clinical findings and development of ADCs for gastric cancer, and summarizes the relevant resistance mechanisms or future directions of ADCs. EXPERT OPINION: Novel HER2-ADCs have led to breakthrough results for HER2+ gastric cancer; however, several questions remain, especially in clinical settings. Translational research to elucidate ADCs' mechanisms of action or resistance will lead to more sophisticated use of ADCs and combination strategies.

U3-1402, a Novel HER3-Targeting Antibody-Drug Conjugate, for the Treatment of Colorectal Cancer.

HER3 is overexpressed in several cancers, including colorectal cancer. Although therapies with anti-HER3 antibodies have been investigated, significant clinical benefits have not been reported. U3-1402 is a novel HER3-antibody-drug conjugate (ADC) composed of the HER3 antibody patritumab and a novel topoisomerase I inhibitor, DX-8951 derivative (DXd). The sensitivity of DXd was evaluated by a growth inhibition assay. The antitumor activity of U3-1402 was evaluated in a murine xenograft model in which its effects on cells, with a range of HER3 expression levels, were compared with those of patritumab alone, irinotecan, control-ADC, and saline. In the growth inhibition assay, all colorectal cancer cell lines were sensitive to DXd. In the tumor xenograft model, significant tumor regression with U3-1402 was observed both in the DiFi cell line (high HER3 expression; KRAS wild type) and in SW620 (high HER3 expression; KRAS mutation), but no treatment effect was observed in Colo320DM (low HER3 expression). Notably, SW620 tumor growth was significantly suppressed with U3-1402 compared with the saline-treated group (P < 0.001) and showed greater activity compared with the irinotecan group. By contrast, patritumab alone, control-ADC, and saline did not significantly differ in tumor growth inhibition. The antitumor activity of U3-1402 was dependent on HER3 expression level, but not on KRAS mutation status. These results support further investigation of development strategies for U3-1402 in patients with HER3-expressing colorectal cancer.

Clinical practice guidance for next-generation sequencing in cancer diagnosis and treatment (Edition 1.0).

In Japan, the social (medical) health-care system is on the way to being developed to advance personalized medicine through the implementation of cancer genomic medicine, known as "cancer clinical sequencing," which uses a next-generation sequencer. However, no Japanese guidance for cancer genomic testing exists. Gene panel testing can be carried out to help determine patient treatment, confirm diagnosis, and evaluate prognostic predictions of patients with mainly solid cancers for whom no standard treatment is available. This guidance describes how to utilize gene panel testing according to the type of cancer: childhood cancer, rare cancer, carcinoma of unknown primary, and other cancers. The level of evidence classification for unified use in Japan is also detailed. This guidance establishes the basic principles of the quality control of specimens, requirements of medical institutions, informed consent, handling of data during the postanalysis stage, and treatment options based on the evidence level. In Japan, gene panel testing for cancer treatment and diagnosis is recommended to comply with this guidance. This is a collaborative work of the Japanese Society of Medical Oncology, Japan Society of Clinical Oncology, and the Japanese Cancer Association.

Prognostic value of programmed death-ligand 1 expression in patients with stage III colorectal cancer.

The programmed death-1/programmed death-ligand 1 (PD-L1) pathway is a negative feedback pathway that suppresses the activity of T cells. Previous studies reported that high PD-L1 expression on tumor cells (TC) was associated with poor survival in patients with colorectal cancer; however, the prognostic evaluation of these studies was limited because they included patients at various disease stages. The purpose of the present study was to evaluate the relationship between PD-L1 status in the immune microenvironment and the clinicopathological features of stage III colorectal cancer. Two hundred and thirty-five patients were included in the analysis. PD-L1 expression on TC and tumor-infiltrating mononuclear cells (TIMC) was evaluated by immunohistochemistry. The median follow-up of thisi study was 52.9 months. A total of 8.1% of stage III colorectal cancer showed high PD-L1 expression on TC and 15.3% showed high PD-L1 expression on TIMC. Patients with high PD-L1 expression on TC had significantly shorter disease-free survival (DFS) than patients with low expression (hazard ratio [HR] 2.36; 95% confidence interval [CI], 1.21-4.62; P = 0.012). In addition, patients with high PD-L1 expression on TIMC were associated with longer DFS than patients with low expression (HR 0.40; 95% CI, 0.16-0.98; P = 0.046). These findings suggest that PD-L1 expression status may be a new predictor of recurrence for stage III colorectal cancer patients and highlight the necessity of evaluating PD-L1 expression on TC and TIMC separately in the tumor microenvironment.

Ewing sarcoma of the liver with multilocular cystic mass formation: a case report.

BACKGROUND: Ewing sarcoma is a rare tumor that occurs commonly in the long bones of children or adolescents that can also arise in soft tissues including the extremities, retroperitoneum, chest wall, and rarely in the liver as primary sites. We report a case of Ewing sarcoma arising primarily in the liver and, to our knowledge, this is the fourth reported case of Ewing sarcoma occurring in the liver. CASE PRESENTATION: A 27-year-old Japanese woman was admitted with sudden onset right upper abdominal pain. Clinical examination revealed a multilocular cystic mass consisting of thickened, irregular septa and nodal walls in the right hepatic lobe. Ultrasound-guided aspiration biopsy of the liver mass showed clusters of small atypical round cells and the clinical preoperative diagnosis was mucinous cystadenoma of the liver. The patient underwent an extended right hepatectomy and histopathological findings revealed sheet-like proliferation of small- to medium-sized round cells. Tumor cells were positive for periodic acid-Schiff reaction and immunoreactive for glycoprotein C99 and gene NKX2.2, as well as the neuroendocrine markers, CD56 and synaptophysin. EWS-FLI-1 fusion transcript type 1 was detected by reverse transcriptase polymerase chain reaction. Pathological and molecular analysis confirmed the diagnosis of Ewing sarcoma arising primarily in the liver and the patient received adjuvant systemic chemotherapy with vincristine, doxorubicin, and cyclophosphamide, alternating with ifosfamide and etoposide. We found no evidence of recurrence 15 months after completing chemotherapy. CONCLUSION: We present an extremely rare case of Ewing sarcoma arising primarily in the liver. To our knowledge, this is the fourth reported case of Ewing sarcoma occurring in the liver, and the first case with a multilocular cystic liver mass. Imaging examinations of the other three reported cases showed solid tumors and a diffuse enlarged liver without mass lesion. Clinicians should consider the possibility of Ewing sarcoma in young patients with a multilocular cystic mass with thick and/or irregular cyst walls in the liver.