Comparison of the Incidence of Adverse Events Between Japanese and Non-Japanese Healthy Subjects in Phase I Studies: A Systematic Review and Meta-Analysis.

BACKGROUND AND OBJECTIVE: Ethnic and racial differences are key factors affecting the results of clinical studies. However, the influence of these factors on the efficacy and safety of medicinal products remains unclear. Race-dependent nature is considered to be one of the factors causing differences in clinical findings, and we investigated its influence on the safety evaluation of drugs. METHODS: We searched PubMed and a Japan drug approval list to find relevant studies, and extracted phase I studies conducted with Japanese and non-Japanese participants using the same protocol and at the same study site. Pooled estimates of odds ratios (ORs) for the incidence of major adverse events in Japanese and non-Japanese participants were calculated, using a DerSimonian-Laird method with a random-effects model. RESULTS: Odds ratios for some adverse events in the active drug arm were significantly lower in Japanese participants: headaches [OR 0.65 (95% confidence interval [CI] 0.52-0.82), p = 0.0003], neurological disorders NEC [OR 0.70 (95% CI 0.53-0.93), p = 0.0135] in a High-Level Group Term, nervous system disorders [OR 0.64 (95% CI 0.49-0.82), p = 0.0004], infections and infestations [OR 0.71 (95% CI 0.53-0.95), p = 0.0202], and musculoskeletal and connective tissue disorders [OR 0.66 (95% CI 0.48-0.91, p = 0.0107] in the System Organ Class. CONCLUSIONS: Our research suggested that racial factors such as race-dependent nature influence a drug safety assessment. With knowledge of these differences, it is expected that Japan will actively conduct multi-regional clinical trials, in which more diverse populations are included.

Total IgE at 6 months predicts remittance or persistence of atopic dermatitis at 14 months.

Some patients with infantile atopic dermatitis (AD) achieve remission around 1 year old, but in others it persists. The difference between them is unclear. We performed a birth cohort study to find the markers predicting the outcome of infantile AD. We followed up a cohort (n = 314) from birth to 14 months of age, and cord blood was taken from the participants. Some of them (n = 144) had a physical examination and a blood test at 6 and 14 months of age. The subjects who had AD at 6 months (n = 34) were divided into two groups, named the transient group (those who had no AD at 14 months of age; n = 16) and the persistent group (those who still had AD at 14 months of age; n = 18). Then, laboratory data were compared between these two groups. Percentage of CD8 in cord blood lymphocytes and total IgE at 6 months of age in the persistent group was significantly higher than those of the transient group. The area under the curves of a receiver operating characteristic analysis were 0.792 (p = 0.007) and 0.722 (p = 0.027). In the persistent group, total IgE, percentages of T-helper (Th) 2 and phytohemagglutinin-induced IL-4 production from peripheral blood mononuclear cells at 14 months of age were also significantly higher than those of the transient group. Thus Th2 polarization in the persistent group was confirmed. In clinical use, total IgE at 6 months of age is the most useful predictive marker to know the outcome of infantile AD. The clinical trial registration ID is UMIN000002926.

Results of Macitentan in Japanese Patients With Chronic Thromboembolic Pulmonary Hypertension　- A Prospective, Multicenter, Open-Label, Single-Arm, Phase 3 Study.

Background: Macitentan, an endothelin-receptor antagonist, is approved in Japan for the treatment of pulmonary arterial hypertension (PAH). This study evaluated the use of macitentan for chronic thromboembolic pulmonary hypertension (CTEPH) in Japanese patients. Methods and Results: This open-label single-arm Phase 3 study evaluated the efficacy and safety of oral macitentan 10 mg (once daily) in Japanese CTEPH patients. The study was prematurely discontinued due to the sponsor's decision to not develop macitentan 10 mg further for the indication of CTEPH (unrelated to safety concerns). Of the 9 patients enrolled in the study, 4 completed 24 weeks of treatment. The mean (±SD) ratio of pulmonary vascular resistance (PVR) at Week 16 to baseline was 71.9±34.3%. The mean (±SD) decreases in PVR and the PVR index (PVRI) from baseline to Week 16 were 181.4±243.9 dyn·s/cm5 and 280.6±366.0 dyn·s·m2/cm5, respectively. The mean (±SD) increase in the 6-min walk distance from baseline to Week 24 was 44.3±46.8 m. All treatment-emergent adverse events (TEAEs) were mild or moderate in severity, except for 1 serious TEAE of angioplasty reported in 1/9 patients that was severe in intensity. Conclusions: Definite conclusions regarding the efficacy of macitentan 10 mg in Japanese patients with CTEPH cannot be drawn because of premature study discontinuation. No safety concerns were observed, and the safety profile was consistent with previously reported studies in CTEPH and PAH patients.

Age-related changes of transforming growth factor beta1 in Japanese children.

BACKGROUND: Transforming growth factor beta1 (TGF beta 1) is an important factor in immunomodulation. The expression of TGF beta 1 has been shown to be influenced by the C-509T polymorphism in the TGF beta 1 gene. We investigated age-related changes of plasma TGF beta 1 levels in a birth-cohort study. In addition, the genotypes of the C-509T polymorphism were investigated in allergic and non-allergic subjects. METHODS: Sixty-four neonates who met the following criteria were enrolled in this cohort study: 1) full-term vaginally delivery; 2) underwent DNA polymorphism analysis; and 3) questionnaire forms were filled out by parents at 0, 6 and 14 months of age. The umbilical cord blood at 0 months and peripheral blood at 6, and 14 months were collected. Plasma TGF beta1 levels were measured at 0, 6 and 14 months of age. Genomic DNA was extracted from their umbilical cord blood. The genotype of the subjects was examined for the presence of C-509T. RESULTS: The plasma TGF beta 1 level at 6 months was the highest of the 3 measurements (at 0, 6, and 14 months of age). The TGF beta 1 levels at 14 months in allergic subjects were significantly higher than those in non-allergic subjects (p = 0.03). All subjects with bronchial asthma (n = 3) had the TT genotype of the C-509T polymorphism. CONCLUSIONS: The plasma TGF beta 1 levels change with age. In addition, TGF beta 1 may play a role in the pathogenesis of bronchial asthma.

Single-base substitution at the last nucleotide of exon 6 (c.671G>A), resulting in the skipping of exon 6, and exons 6 and 7 in human succinyl-CoA:3-ketoacid CoA transferase (SCOT) gene.

Succinyl-CoA:3-ketoacid CoA transferase (SCOT, EC 2.8.3.5) is the key enzyme for ketone body utilization. Hereditary SCOT deficiency (MIM 245050) causes episodes of severe ketoacidosis. We identified a homozygous point mutation (c.671G>A) , which is a single-base substitution at the last nucleotide of exon 6, in a Turkish patient (GS12) with SCOT deficiency. This point mutation resulted in the skipping of exon 6, and exons 6 and 7 in human SCOT genes. To understand why the c.671G>A causes exons 6 and 7 skipping, nuclear RNA was separated from cytoplasmic RNA and both were analyzed by RT-PCR. In nuclear RNA, SCOT mRNA with exon 6 skipping was predominant and mRNA with exons 6 and 7 skipping was hardly detected, whereas the latter became one of major mRNA species in cytoplasmic RNA. This discrepancy was interpreted as follows: exon 6 skipping causes a frameshift and nonsense-mediated RNA decay in the cytosol, so mRNA with exon 6 skipping was unstable. On the other hand, SCOT mRNA with exons 6 and 7 is a minor transcript but it retains the reading-frame and is stable in cytosol. As a result, the latter mRNA is more abundant under steady-state conditions as compared to the former mRNA.

Kinetic and expression analyses of seven novel mutations in mitochondrial acetoacetyl-CoA thiolase (T2): identification of a Km mutant and an analysis of the mutational sites in the structure.

Mitochondrial acetoacetyl-CoA thiolase (T2) deficiency is an inborn error of metabolism that affects isoleucine catabolism and ketone body metabolism. We identified 7 novel and 2 previously reported mutations in six T2-deficient patients. Transient expression analysis of wild-type and eight mutant cDNAs was performed at 40, 37 and 30 degrees C. Although no significant residual activity was detected, mutant proteins were detected in the N158D, N158S, R208Q, Y219H and N282H mutants. Accumulation of these mutant proteins was temperature-sensitive with the highest expression levels at lower temperatures. Expression of Q73P and N353K cDNAs yielded neither residual T2 protein nor enzyme activity. An E252del mutant T2 was detected with a relative protein amount and enzyme activity of 30% and 25%, respectively, in comparison to the wild-type at 37 degrees C. The E252del mutant protein was more stable at 30 degrees C expression than 37 degrees C, but was essentially undetectable at 40 degrees C, indicating its temperature-sensitive instability. Kinetic studies revealed a twofold K(m) elevation for substrates coenzyme A and acetoacetyl-CoA in the E252del mutant, while V(max) was comparable to the wild-type. We conclude that the E252del is a temperature-sensitive K(m) mutant. This correlates well with the effect predicted from the T2 tertiary structure analysis, using the crystal structure of the human T2 homotetramer. The probable effect of the other mutations on the T2 tertiary structure was also evaluated.

A 6-bp deletion at the splice donor site of the first intron resulted in aberrant splicing using a cryptic splice site within exon 1 in a patient with succinyl-CoA: 3-Ketoacid CoA transferase (SCOT) deficiency.

Succinyl-CoA: 3-ketoacid-CoA transferase (SCOT; locus symbol OXCT, EC 2.8.3.5) deficiency is a rare genetic disorder affecting ketone body utilization in extra-hepatic tissues. A 6-bp deletion at the splice donor site of intron 1 resulted in the absence of a full-length mature SCOT mRNA with faint amounts of aberrantly spliced transcripts using a cryptic splice donor site within exon 1, which was located just 7 bases upstream from the authentic site in a SCOT deficient patient.

Identification of Alu-mediated, large deletion-spanning exons 2-4 in a patient with mitochondrial acetoacetyl-CoA thiolase deficiency.

Mitochondrial acetoacetyl-CoA thiolase (T2) deficiency is a rare inherited metabolic disorder affecting isoleucine catabolism and ketone body metabolism. So far, more than 39 different mutations have been identified in 60 T2-deficient patients. However, no large deletions have been reported. We herein report the first case of a large T2 gene deletion from intron 1 to intron 4 in a T2-deficient patient (GK41). cDNA analysis revealed that an aberrant cDNA with exons 2-5 skipping was a major transcript, associated with a minor transcript of exons 2-4 skipping with a 94-bp insertion composed of an intron 1 sequence. Genomic analysis indicated an absence of PCR amplification of exons 2-4 and gene deletion was revealed by Southern blot analysis. Cloning and sequencing long range PCR products revealed a 6.4kb deletion. Alu element-mediated unequal homologous recombination between an Alu-Sx in intron 1 and another Alu-Y in intron 4 appears to be responsible for this deletion.

Age-related changes in intracellular cytokine profiles and Th2 dominance in allergic children.

The unbalanced T helper response has been pointed out in allergic diseases. Especially in childhood, it is important to consider the development of acquired immunity. We investigated the relationship between age and Th1, Th2, Tc1 or Tc2 cells. In addition, Th1, Th2, Tc1 or Tc2 cells in allergic diseases were compared with control subjects. Thirty-four healthy controls (0-40 years old), 200 samples of cord blood, nine patients with atopic dermatitis (AD) (1-3 years old) and five patients with bronchial asthma (BA) (2-6 years old) were studied. Surface staining with CD4, CD8 and intracellular staining with anti-interferon-gamma (IFN-gamma) and anti-interleukin (IL)-4 were carried out, and analyzed by using flow cytometry. In the healthy controls, the percentages of Th1, Tc1 or Th2 showed positive correlation with age. The absolute numbers of Th1 or Tc1 also correlated with age. Cord blood with a family history of allergic disease showed no significant difference compared to that without a family history. The percentage of Th2 in AD and BA patients was significantly higher than in the age-matched healthy controls. The increase in Th1, Th2 and Tc1 with age might reflect on the development of acquired immunity. Age matching is important when evaluating the cytokine profiles of T cells. In allergic diseases, although cord blood showed a Th1-dominant pattern, it changed to Th2 dominance in childhood, and this may reflect on some genetic background.