The notorious "drug lag" for oncology drugs in Japan

This study aimed to analyze the oncology “drug lag” (i.e., the delay in time required for the approval of oncology drugs) in Japan compared with that in the United States of America (US) or the European Union (EU) and to identify the factors associated with this lag. Using publicly available information, we collected data on 42 approvals of 30 oncology drugs in Japan, the US, and the EU that included dates of drug development initiation, submission, review, and approval. Lags in each step of the process were then examined and compared among the three regions. We found that median submission and approval lag times between Japan and the US were 20.0 and 29.9 months, respectively, while those between Japan and the EU were 14.9 and 21.3 months, respectively. The median review periods for Japan, the US, and the EU were 14.3, 6.0, and 13.2 months, respectively, and the median lag in initiation of oncology drug development between Japan and the US/EU was 38.9 months. The proportion of approvals for which Japanese Phase I registration trials started after corresponding approvals in the US were 39% compared with 47% for the EU. Multivariate analysis suggests that delays in the initiation of drug development and the extended length of the regulatory review period in Japan may contribute to the longer oncology drug lag observed in Japan compared with that of the US or EU.     

Anti-stromal therapy with imatinib inhibits growth and metastasis of gastric carcinoma in an orthotopic nude mouse model

Recent studies have revealed that platelet-derived growth factor (PDGF) plays a role in promoting progressive tumor growth in several organs; however, whether PDGF plays such a role in gastric carcinoma is undetermined. We examined whether inhibition of PDGF receptor (PDGF-R) tyrosine kinase signaling by imatinib affects tumor growth and metastasis in an orthotopic nude mouse model of human gastric carcinoma. TMK-1 human gastric carcinoma cells were injected into the gastric wall of nude mice. Groups of mice (n = 10 each) received sterile water (control), low-dose imatinib (50 mg/kg/day), high-dose imatinib (200 mg/kg/day), cancer chemotherapeutic agent irinotecan (5 mg/kg/week), or imatinib (50 mg/kg/day or 200 mg/kg/day) and irinotecan (5 mg/kg/week) in combination for 28 days. Tumor growth and metastasis were assessed. Resected tumors were analyzed immunohistochemically. Carcinoma-associated fibroblasts, pericytes and lymphatic endothelial cells in stroma expressed high levels of PDGF-R; carcinoma cells did not. Treatment with imatinib alone did not inhibit tumor growth and metastasis; however, treatment with irinotecan alone or combined with imatinib significantly inhibited tumor growth. Only treatment with high-dose imatinib and irinotecan in combination inhibited lymph node and peritoneal metastases. Immunohistochemically, only imatinib alone or in combination with irinotecan was shown to significantly decrease the stromal reaction, microvessel area and pericyte coverage of tumor microvessels. These effects were marked with high-dose imatinib. In conclusion, administration of PDGF-R tyrosine kinase inhibitor in combination with irinotecan appears to impair the progressive growth of gastric carcinoma by blockade of PDGF-R signaling pathways in stromal cells.     

Lectin microarray analysis of pluripotent and multipotent stem cells

Stem cells have a capability to self-renew and differentiate into multiple types of cells; specific markers are available to identify particular stem cells for developmental biology research. In this study, we aimed to define the status of somatic stem cells and the pluripotency of human embryonic stem (hES) and induced pluripotent stem (iPS) cells using a novel molecular methodology, lectin microarray analysis. Our lectin microarray analysis successfully categorized murine somatic stem cells into the appropriate groups of differentiation potency. We then classified hES and iPS cells by the same approach. Undifferentiated hES cells were clearly distinguished from differentiated hES cells after embryoid formation. The pair-wise comparison means based on 'false discovery rate' revealed that three lectins -Euonymus europaeus lectin (EEL), Maackia amurensis lectin (MAL) and Phaseolus vulgaris leucoagglutinin [PHA(L)]- generated maximal values to define undifferentiated and differentiated hES cells. Furthermore, to define a pluripotent stem cell state, we generated a discriminant for the undifferentiated state with pluripotency. The discriminant function based on lectin reactivities was highly accurate for judgment of stem cell pluripotency. These results suggest that glycomic analysis of stem cells leads to a novel comprehensive approach for quality control in cell-based therapy and regenerative medicine.     

Deep Brain Stimulation for Tourette Syndrome: A Prospective Pilot Study in Japan

Objective: Refractory Tourette syndrome (TS) disturbs the social life of patients. Deep brain stimulation (DBS) has recently been applied to relieve severe tics. We report a prospective open‐labeled case series of DBS for TS as a pilot study. Cases and Methods: Three patients (19–21 years old, one male) with refractory TS were treated with DBS. They were targeted at the centromedian‐parafascicular complex‐ventral oral thalamic nuclei of the bilateral thalami. Results: The scores for the Yale Global Tic Severity Scale decreased from 42.7 ± 2.7 (before DBS) to 26.0 ± 1.7 (one year after DBS) (means ± standard error of means). Intelligence levels of the patients showed no change after surgery. There was no morbidity or mortality. All patients presented an increase in satisfaction with activities of daily living. Conclusions: These results support the safety and efficacy of thalamic DBS for TS.     

Two cases of cerebral embolism caused by apical thrombi in midventricular obstructive cardiomyopathy

Midventricular obstructive hypertrophic cardiomyopathy (MOHC) is a rare form of cardiomyopathy that was demonstrated to have caused embolic stroke in two patients. In both cases, the embolic sources of stroke were thrombi in an apical aneurysm caused by turbulent stasis of blood flow and subsequent injury of myocardial endocardium. Even without atrial fibrillation, apical aneurysm can induce emboligenic stroke in MOHC.