[PMDA's Initiatives to Encourage the New Drug Development for Rare Cancers].

Rare cancers, estimated to account for 15% of all cancers, have many unmet medical needs, but at the same time, developing treatments for these cancers is fraught with difficulties. PMDA's efforts to promote and support the development of treatments for rare cancers include the development consultation to meet the needs of emerging biopharma(EBP), promotion of development through multi-regional clinical trials, and development support for investigator-initiated clinical trials. In addition, the development environment for rare cancers and rare subtypes has been improved through the revision of clinical evaluation guidelines, consultation programs and guidance publication for the utilization of RWDs, and the accumulation of tissue-agnostic cancer drug approvals. Regarding the Orphan Drug Designation System, about one-third of the 267 drugs designated during the 15-year period from 2004-2018 were anti-cancer drugs. Looking at the approvals of anti-cancer drugs during the past 10 years(2013-2022), 26%(53/203)of drugs for solid tumors and 60%(62/104)of drugs for hematologic tumors received orphan drug designation. Regulatory measures that support the development for rare cancers include not only the Orphan Drug Designation but also the Conditional Accelerated Approval, which facilitates the development of drugs for diseases where timely conduct of a confirmatory clinical trial is difficult, and the Sakigake Designation that allows the accelerated approval of innovative new drugs. PMDA will continue its efforts to promote drug development in response to changes of the circumstances surrounding drug development as well as developer's need and will make further efforts to disseminate information of those measures both domestically and internationally.

Peripheral combination treatment of leptin and an SGLT2 inhibitor improved glucose metabolism in insulin-dependent diabetes mellitus mice.

We investigated whether peripheral combination treatment of a sodium-glucose cotransporter 2 (SGLT2) inhibitor and leptin improves glucose metabolism in insulin-dependent diabetes mellitus (IDDM) model mice. Twelve-week-old male C57BL6 mice were intraperitoneally administered a high dose of streptozotocin to produce IDDM. IDDM mice were then divided into five groups: SGLT2 inhibitor treatment alone, leptin treatment alone, leptin and SGLT2 inhibitor co-treatment, untreated IDDM mice, and healthy mice groups. The blood glucose (BG) level at the end of the dark cycle was measured, and a glucose tolerance test (GTT) was performed and compared between the five groups. Leptin was peripherally administered at 20 µg/day using an osmotic pump, and an SGLT2 inhibitor, ipragliflozin, was orally administered at 3 mg/kg/day. Monotherapy with SGLT2 inhibitor or leptin significantly improved glucose metabolism in mice as evaluated by BG and GTT compared with the untreated group, whereas the co-treatment group with SGLT2 inhibitor and leptin further improved glucose metabolism as compared with the monotherapy group. Notably, glucose metabolism in the co-treatment group improved to the same level as that in the healthy mice group. Thus, peripheral combination treatment with leptin and SGLT2 inhibitor improved glucose metabolism in IDDM mice without the use of insulin.

GABAB receptor signaling in the caudate putamen is involved in binge-like consumption during a high fat diet in mice.

Previous studies suggest that signaling by the gamma-aminobutyric acid (GABA) type B receptor (GABABR) is involved in the regulation of binge eating, a disorder which might contribute to the development of obesity. Here, we show that intermittent access to a high fat diet (HFD) induced binge-like eating behavior with activation of dopamine receptor d1 (drd1)-expressing neurons in the caudate putamen (CPu) and nucleus accumbens (NAc) in wild-type (WT) mice. The activation of drd1-expressing neurons during binge-like eating was substantially increased in the CPu, but not in the NAc, in corticostriatal neuron-specific GABABR-deficient knockout (KO) mice compared to WT mice. Treatment with the GABABR agonist, baclofen, suppressed binge-like eating behavior in WT mice, but not in KO mice, as reported previously. Baclofen also suppressed the activation of drd1-expressing neurons in the CPu, but not in the NAc, during binge-like eating in WT mice. Thus, our data suggest that GABABR signaling in CPu neurons expressing drd1 suppresses binge-like consumption during a HFD in mice.

Glucocorticoid receptor signaling in ventral tegmental area neurons increases the rewarding value of a high-fat diet in mice.

The reward system, which consists of dopaminergic neurons projecting from the ventral tegmental area (VTA) to the nucleus accumbens and caudate-putamen in the striatum, has an important role in the pathogenesis of not only drug addiction but also diet-induced obesity. In the present study, we examined whether signaling through glucocorticoid receptors (GRs) in the reward system affects the rewarding value of a high-fat diet (HFD). To do so, we generated mice that lack functional GRs specifically in dopaminergic neurons (D-KO mice) or corticostriatal neurons (CS-KO mice), subjected the mice to caloric restriction stress conditions, and evaluated the rewarding value of a HFD by conditioned place preference (CPP) test. Caloric restriction induced increases in serum corticosterone to similar levels in all genotypes. While CS-KO as well as WT mice exhibited a significant preference for HFD in the CPP test, D-KO mice exhibited no such preference. There were no differences between WT and D-KO mice in consumption of HFD after fasting or cognitive function evaluated by a novel object recognition test. These data suggest that glucocorticoid signaling in the VTA increases the rewarding value of a HFD under restricted caloric stress.

Dietary sodium chloride attenuates increased ß-cell mass to cause glucose intolerance in mice under a high-fat diet.

Excessive sodium salt (NaCl) or fat intake is associated with a variety of increased health risks. However, whether excessive NaCl intake accompanied by a high-fat diet (HFD) affects glucose metabolism has not been elucidated. In this study, C57BL/6J male mice were fed a normal chow diet (NCD), a NCD plus high-NaCl diet (NCD plus NaCl), a HFD, or a HFD plus high-NaCl diet (HFD plus NaCl) for 30 weeks. No significant differences in body weight gain, insulin sensitivity, and glucose tolerance were observed between NCD-fed and NCD plus NaCl-fed mice. In contrast, body and liver weights were decreased, but the weight of epididymal white adipose tissue was increased in HFD plus NaCl-fed compared to HFD-fed mice. HFD plus NaCl-fed mice had lower plasma glucose levels in an insulin tolerance test, and showed higher plasma glucose and lower plasma insulin levels in an intraperitoneal glucose tolerance test compared to HFD-fed mice. The ß-cell area and number of islets were decreased in HFD plus NaCl-fed compared to HFD-fed mice. Increased Ki67-positive ß-cells, and increased expression levels of Ki67, CyclinB1, and CyclinD1 mRNA in islets were observed in HFD-fed but not HFD plus NaCl-fed mice when compared to NCD-fed mice. Our data suggest that excessive NaCl intake accompanied by a HFD exacerbates glucose intolerance, with impairment in insulin secretion caused by the attenuation of expansion of ß-cell mass in the pancreas.

High-fat Feeding Causes Inflammation and Insulin Resistance in the Ventral Tegmental Area in Mice.

The reward system plays an important role in the pathogenesis of not only drug addiction, but also diet-induced obesity. Recent studies have shown that insulin and leptin receptor signaling in the ventral tegmental area (VTA) regulate energy homeostasis and that their dysregulation is responsible for obesity and altered food preferences. Although a high-fat diet (HFD) induces inflammation that leads to insulin and leptin resistance in the brain, it remains unclear whether HFD induces inflammation in the VTA. In the present study, we placed male mice on a chow diet or HFD for 3, 7, and 28 days and evaluated the mRNA expression of inflammatory cytokines and microglial activation markers in the VTA. The HFD group showed significantly elevated mRNA expressions of IL1ß at 3 days; tumor necrosis factor-alpha (TNFα), IL1ß, IL6, Iba1, and CD11b at 7 days; and TNFα, IL1ß, Iba1, and CD11b at 28 days. The changes in TNFα were also confirmed in immunohistochemical analysis. Next, after administration of chow or HFD for 7 days, we selected mice with equal weights in both groups. In experiments using these mice, Akt phosphorylation in the VTA was significantly decreased after intracerebroventricular injection of insulin, whereas no change in STAT3 phosphorylation was found with leptin. Taken together, these results suggest that HFD induces inflammation at least partly associated with microglial activation in the VTA leading to insulin resistance, independently of the energy balance. Our data provide new insight into the pathophysiology of obesity caused by a dysfunctional reward system under HFD conditions.

Hypothalamic glial cells isolated by MACS reveal that microglia and astrocytes induce hypothalamic inflammation via different processes under high-fat diet conditions.

Glial cells can mediate hypothalamic inflammatory processes induced in response to a high-fat diet (HFD). We used magnetic-activated cell sorting (MACS) to isolate microglia and astrocytes from hypothalamus of mice fed HFD and examined changes in expression of inflammation-related cytokines and markers related to glial cell activation status. Hypothalamus from male C57BL6 mice fed a chow diet (chow) or HFD for 1, 3, or 28 days were collected and microglia and astrocytes were isolated by MACS. After confirming cell viability by fluorescence activated cell sorting, mRNA expression levels of inflammation-related cytokines and markers of glial cell activation status were examined by qRT-PCR, which revealed that both glial cell types isolated by MACS retained specificity. On day 3 of HFD, both CD86 and TNFα mRNA expression was significantly increased in microglia relative to the chow group. In astrocytes, TNFα mRNA expression levels were similar between the chow and HFD groups on day 3, but anti-inflammatory cytokine IL-10 levels were significantly increased. On day 7 of HFD, TNFα expression in microglia decreased to levels comparable to the chow group while that in astrocytes remained unchanged. On day 28 of HFD, TNFα levels were significantly increased in both microglia and astrocytes, which had increased mRNA expression of CD86 and MAO-B, respectively. For both glial cell types, results for TNFα expression assessed by RT-PCR and immunohistochemical analysis were similar. These results indicate that the role of microglia and astrocytes in hypothalamic inflammation under HFD conditions changed with time and these changes were accompanied by changes in the activation status of glial cells. Our data suggest that early after initiating HFD, hypothalamic astrocytes suppress diet-induced inflammation at least in part by secreting IL-10, whereas continued HFD feeding impairs this suppressive function such that both microglia and astrocytes promote hypothalamic inflammation.

Investigation of displaced bronchi using multidetector computed tomography: associated abnormalities of lung lobulations, pulmonary arteries and veins.

OBJECTIVE: Although several cases of thoracic surgery for patients with displaced bronchi have been reported, there are few reports describing the anatomical features of displaced bronchi. The author aimed to analyze the incidence and types of displaced bronchi, and their associated lung lobulations and vascular courses. METHODS: Of 6480 patients who underwent thoracic computed tomography at our hospital from 2012 to 2016, 6072 were included. Displaced bronchi were classified according to their associated lobes and were subclassified based on each lobar or segmental bronchus. Subsequently, the author analyzed the associated abnormalities of lung lobulations and vascular courses. RESULTS: Of 6072 patients, displaced bronchi were observed in 46 (0.76%): the right upper lobe in 39, the right lower lobe in two, and the left upper lobe in five patients. In the right upper lobe, "Right Upper Lobar Type" was found in six patients "Right B1 Type" in 15, "Right B2 Type" in seven, and "Right B3 Type" in 11 patients. All right lower lobar displaced bronchi were "Right B6 Type" and all left upper lobar displaced bronchi were "Left B1+2 Type". In the Right B2, Right B3, and Left B1+2 Types, abnormal lung lobulations and top pulmonary veins were frequently noted. All patients with the Right B3 and Left B1+2 Types had unique abnormalities of the pulmonary arteries. CONCLUSIONS: In some types of displaced bronchi, both abnormal lobulations and top pulmonary veins may be useful for recognizing displaced bronchi.

GABAB Receptor Signaling in the Mesolimbic System Suppresses Binge-like Consumption of a High-Fat Diet.

Binge eating could contribute to the development of obesity, and previous studies suggest that gamma-aminobutyric acid (GABA) type B receptor (GABABR) signaling is involved in the regulation of binge eating. Here, we show that time-restricted access to a high-fat diet (HFD) induces binge-like eating behavior in wild-type mice. HFD consumption during restricted time was significantly increased in corticostriatal neuron-specific GABABR-deficient mice compared with wild-type mice. Furthermore, the GABABR agonist baclofen suppressed HFD intake during restricted time in wild-type mice but not in corticostriatal or dopaminergic neuron-specific GABABR-deficient mice. In contrast, there were no significant differences in food consumption among genotypes under ad libitum access to HFD. Thus, our data show that the mesolimbic system regulates food consumption under time-restricted but not ad libitum access to HFD and have identified a mechanism by which GABABR signaling suppresses binge-like eating of HFD.

Long-term outcomes after video-assisted thoracic surgery (VATS) lobectomy versus lobectomy via open thoracotomy for clinical stage IA non-small cell lung cancer.

BACKGROUND: Video-assisted thoracic surgery (VATS) lobectomy is a standard treatment for lung cancer. This study retrospectively compared long-term outcomes after VATS lobectomy versus lobectomy via open thoracotomy for clinical stage IA non-small cell lung cancer (NSCLC). METHODS: From July 2002 to June 2012, 160 patients were diagnosed with clinical stage IA NSCLC and underwent lobectomy. Of these, 114 underwent VATS lobectomy and 46 underwent lobectomy via open thoracotomy. RESULTS: The 5-year disease-free survival (DFS) rate was 88.0% in the VATS group and 77.1% in the thoracotomy group for clinical stage IA NSCLC (p = 0.1504), and 91.5% in the VATS group and 93.8% in the thoracotomy group for pathological stage IA NSCLC (p = 0.2662). The 5-year overall survival (OS) rate was 94.1% in the VATS group and 81.8% in the thoracotomy group for clinical stage IA NSCLC (p = 0.0268), and 94.8% in the VATS group and 96.2% in the thoracotomy group for pathological stage IA NSCLC (p = 0.5545). The rate of accurate preoperative staging was 71.9% in the VATS group and 56.5% in the thoracotomy group (p = 0.2611). Inconsistencies between the clinical and pathological stages were mainly related to tumor size, nodal status, and pleural invasion. Local recurrence occurred for one lesion in the VATS group and six lesions (five patients) in the thoracotomy group (p = 0.0495). CONCLUSIONS: The DFS and OS were not inferior after VATS compared with thoracotomy. Local control was significantly better after VATS than after thoracotomy. Preoperative staging lacked sufficient accuracy.

Recent advances in immunotherapy for non-small-cell lung cancer.

Despite of recent development in the field of molecular targeted therapies, lung cancer is a leading cause of cancer death in the world. Remarkable progress has been made recently in immunotherapy for patients with non-small-cell lung cancer (NSCLC), with several modalities, concepts, and treatment settings being investigated. In vaccine development, large-scale clinical trials such as those with L-BLP25, belagenpumatucel-L, TG4010, and talactoferrin are already ongoing and some results have been reported. A trial of a vaccine as adjuvant therapy for patients with completely resected NSCLC is also ongoing with one of the major cancer-testis antigens, melanoma-associated antigen (MAGE)-A3. More recently, the effectiveness of multiple peptide vaccines has also been shown. Recently developed unique treatment modalities are the immune checkpoint inhibitors, such as antibodies against PD-1 and PD-L1, which also show promise. However, although therapeutic cancer vaccines are generally thought to be safe, severe adverse events should be monitored carefully when using immune checkpoint inhibitors. Here, we discuss recent advances and future perspectives of immunotherapy for patients with NSCLC.

Multiple therapeutic peptide vaccines consisting of combined novel cancer testis antigens and anti-angiogenic peptides for patients with non-small cell lung cancer.

BACKGROUND: Vaccine treatment using multiple peptides derived from multiple proteins is considered to be a promising option for cancer immune therapy, but scientific evidence supporting the therapeutic efficacy of multiple peptides is limited. METHODS: We conducted phase I trials using a mixture of multiple therapeutic peptide vaccines to evaluate their safety, immunogenicity and clinical response in patients with advanced/recurrent NSCLC. We administered two different combinations of four HLA-A24-restricted peptides. Two were peptides derived from vascular endothelial growth factor receptor 1 (VEGFR1) and 2 (VEGFR2), and the third was a peptide derived from up-regulated lung cancer 10 (URLC10, which is also called lymphocyte antigen 6 complex locus K [LY6K]). The fourth peptide used was derived from TTK protein kinase (TTK) or cell division associated 1 (CDCA1). Vaccines were administered weekly by subcutaneous injection into the axillary region of patients with montanide ISA-51 incomplete Freund's adjuvant, until the disease was judged to have progressed or patients requested to be withdrawn from the trial. Immunological responses were primarily evaluated using an IFN-gamma ELiSPOT assay. RESULTS: Vaccinations were well tolerated with no severe treatment-associated adverse events except for the reactions that occurred at the injection sites. Peptide-specific T cell responses against at least one peptide were observed in 13 of the 15 patients enrolled. Although no patient exhibited complete or partial responses, seven patients (47%) had stable disease for at least 2 months. The median overall survival time was 398 days, and the 1- and 2-year survival rates were 58.3% and 32.8%, respectively. CONCLUSION: Peptide vaccine therapy using a mixture of four novel peptides was found to be safe, and is expected to induce strong specific T cell responses. TRIAL REGISTRATION: These studies were registered with ClinicalTrials.gov NCT00633724 and NCT00874588.

Understanding the response of dendritic cells to activation by streptococcal preparation OK-432.

BACKGROUND: The streptococcal preparation OK-432 induces maturation of T cells and dendritic cells (DCs). However, the mechanisms by which OK-432 induces DC maturation are not well understood. MATERIALS AND METHODS: The effects of OK-432 and TNF-alpha on peripheral blood mononuclear cells (PBMCs) were compared. Antibody-based approaches were used to detect proteins characteristic of antigen-presenting cells and cytokines. Cytotoxicity was evaluated by measuring the release of LDH after incubation of effector and target cells. The TLR-4 levels were measured by real-time quantitative PCR. RESULTS: Changes in cell surface marker levels were detected in both treatment groups but OK-432 had a greater effect on induction of Th-1-type cytokines. Furthermore, TLR-4 mRNA was up-regulated in cells from two out of five patients in response to OK-432, but not in response to TNF-alpha. CONCLUSION: OK-432 has a more profound effect on human DCs than TNF-alpha and may act through multiple signaling pathways.

Possible participation of intracellular platelet-activating factor in NF-kappaB activation in rat peritoneal macrophages.

As we had found previously that thapsigargin, an endomembrane Ca2+-ATPase inhibitor, induces production of intracellular platelet-activating factor (PAF) [Br. J. Pharmacol. 116 (1995) 2141], we decided to investigate the possible roles of intracellular PAF in nuclear factor (NF)-kappaB activation of thapsigargin-stimulated rat peritoneal macrophages. When rat peritoneal macrophages were stimulated with thapsigargin, the level of inhibitory protein of NF-kappaB-alpha (IkappaB-alpha) was decreased and the nuclear translocation of NF-kappaB was increased. The thapsigargin-induced activation of NF-kappaB was inhibited by the PAF synthesis inhibitor SK&F 98625 and the PAF antagonist E6123. Structurally unrelated PAF antagonists such as E5880 and L-652,731 also inhibited the thapsigargin-induced activation of NF-kappaB. Lipopolysaccharide (LPS)-induced activation of NF-kappaB was also suppressed by these drugs. In a culture of rat peritoneal macrophages, exogenously added PAF did not induce degradation of IkappaB-alpha. These findings suggest that the intracellular PAF produced by the stimulation with thapsigargin or LPS is involved in activation of the NF-kappaB pathway.

Participation of prostaglandin E2 and platelet-activating factor in thapsigargin-induced production of interleukin-6.

Incubation of rat peritoneal macrophages in the presence of thapsigargin increased production of prostaglandin E2, intracellular platelet-activating factor (PAF) and interleukin-6. However, no PAF was detected in the conditioned medium. In the presence of SK&F 98625 (diethyl 7-(3,4,5-triphenyl-2-oxo-2,3-dihydroimidazol-1-yl)heptane phosphonate), a CoA-independent transacylase inhibitor, the thapsigargin-induced increases in the interleukin-6 mRNA level and interleukin-6 production were suppressed in a concentration-dependent manner. This inhibitor also suppressed the production of prostaglandin E2 and intracellular PAF. The PAF receptor antagonists such as E6123 ((S)-(+)-6-(2-chlorophenyl)-3-cyclopropanecarbonyl-8,11-dimethyl-2,3,4,5-tetrahydro-8H-pyrido[4',3':4,5]thieno[3,2-f][1,2,4]triazolo [4,3-a][1,4]diazepine) and L-652,731 (2,5-bis(3,4,5-trimethylphenyl)tetrahydrofuran) partially inhibited the thapsigargin-induced increase in the levels of interleukin-6 mRNA and interleukin-6 protein. The SK&F 98625-induced suppression of interleukin-6 mRNA accumulation and interleukin-6 production was partially restored by addition of exogenous prostaglandin E2. However, exogenous PAF failed to reverse the suppression suggesting that the intracellular PAF does not act in an autocrine mechanism. These findings suggested that the concurrently produced prostaglandin E2 and intracellular PAF participate in the thapsigargin-induced increase in the interleukin-6 mRNA level and interleukin-6 production by rat peritoneal macrophages.