Iduronate-2-Sulfatase with Anti-human Transferrin Receptor Antibody for Neuropathic Mucopolysaccharidosis II: A Phase 1/2 Trial.

Hunter syndrome (mucopolysaccharidosis II [MPS II]), a deficiency of iduronate-2-sulfatase (IDS), causes an accumulation of glycosaminoglycans, giving rise to multiple systemic and CNS symptoms. The currently available therapies, idursulfase and idursulfase beta, are ineffective against the CNS symptoms because they cannot pass the blood-brain barrier (BBB). A novel IDS fused with anti-human transferrin receptor antibody (JR-141) has been shown to penetrate the BBB and ameliorate learning deficits in model mice. This first-in-human study evaluated the pharmacokinetics, safety, and potential efficacy of JR-141 in 14 patients with MPS II. In a dose-escalation study performed in two patients, JR-141 plasma concentrations were dose dependent and peaked at 3 hr after initiation of each infusion, and no or only mild adverse reactions were exhibited. In a subsequent 4-week evaluation at two dose levels, the plasma concentration profiles were similar between the first and final administration, indicating no drug accumulation. Levels of heparan sulfate (HS) and dermatan sulfate (DS) were suppressed in both plasma and urine and HS levels were significantly decreased in cerebrospinal fluid. Two patients experienced some amelioration of neurocognitive and motor symptoms. These results suggest that the drug successfully penetrates the BBB and could have CNS efficacy.

A Blood-Brain-Barrier-Penetrating Anti-human Transferrin Receptor Antibody Fusion Protein for Neuronopathic Mucopolysaccharidosis II.

Mucopolysaccharidosis II (MPS II) is an X-linked recessive lysosomal storage disease caused by mutations in the iduronate-2-sulfatase (IDS) gene. Since IDS catalyzes the degradation of glycosaminoglycans (GAGs), deficiency in this enzyme leads to accumulation of GAGs in most cells in all tissues and organs, resulting in severe somatic and neurological disorders. Although enzyme replacement therapy with human IDS (hIDS) has been used for the treatment of MPS II, this therapy is not effective for defects in the CNS mainly because the enzyme cannot cross the blood-brain barrier (BBB). Here, we developed a BBB-penetrating fusion protein, JR-141, which consists of an anti-human transferrin receptor (hTfR) antibody and intact hIDS. The TfR-mediated incorporation of JR-141 was confirmed by using human fibroblasts in vitro. When administrated intravenously to hTfR knockin mice or monkeys, JR-141, but not naked hIDS, was detected in the brain. In addition, the intravenous administration of JR-141 reduced the accumulation of GAGs both in the peripheral tissues and in the brain of hTfR knockin mice lacking Ids, an animal model of MPS II. These data provide a proof of concept for the translation of JR-141 to clinical study for the treatment of patients with MPS II with CNS disorders.

Evaluation of cerebrospinal fluid heparan sulfate as a biomarker of neuropathology in a murine model of mucopolysaccharidosis type II using high-sensitivity LC/MS/MS.

Mucopolysaccharidosis type II (MPS II or Hunter syndrome) is a lysosomal storage disorder caused by a deficiency of iduronate-2-sulfatase (IDS), an enzyme that catabolizes glycosaminoglycans (GAGs) including heparan sulfate (HS) and dermatan sulfate (DS). GAG accumulation leads to severe neurological and somatic impairments. At present, the most common treatment for MPS II is intravenous enzyme replacement therapy; however, the inability of recombinant IDS to cross the blood-brain barrier (BBB) restricts therapeutic efficacy for neurological manifestations. We recently developed a BBB-penetrating IDS fusion protein, JR-141, and demonstrated its ability to reduce GAG accumulation in the brain of human transferrin receptor knock-in and Ids knock-out mice (TFRC-KI/Ids-KO), an animal model of MPS II, following intravenous administration. Given the impossibility of measuring GAG accumulation in the brains of human patients with MPS II, we hypothesized that GAG content in the cerebrospinal fluid (CSF) might serve as an indicator of brain GAG burden. To test this hypothesis, we optimized a high-sensitivity method for quantifying HS and DS in low-volume samples by combining acidic methanolysis and liquid chromatography-tandem mass spectrometry (LC/MS/MS). We employed this method to quantify HS and DS in samples from TFRC-KI/Ids-KO mice and revealed that HS but not DS accumulated in the central nerve system (CNS). Moreover, concentrations of HS in CSF correlated with those in brain. Finally, intravenous treatment with JR-141 reduced levels of HS in the CSF and brain in TFRC-KI/Ids-KO mice. These results suggest that CSF HS content may be a useful biomarker for evaluating the brain GAG accumulation and the therapeutic efficacy of drugs in patients with MPS II.

Continuing efforts to standardize measured serum growth hormone values in Japan.

Determination of serum growth hormone (GH) levels is mandatory for diagnosis of GH deficiency and excess. In the present study, we, the Study Committee for GH and Its Related Factors, The Foundation for Growth Science, Japan measured GH values in serum samples using all the commercially available kits in Japan. Significant discrepancies in the GH values were observed among the kits in spite of using the unified recombinant human GH-based standards. To deal with the discrepancies, we established a formula using a linear structural relationship model and were able to standardize the GH values. We propose to use the formula to diagnose GH deficiency and excess in Japan.

Standardized centile curves and reference intervals of serum insulin-like growth factor-I (IGF-I) levels in a normal Japanese population using the LMS method.

Measurements of insulin-like growth factor-I (IGF-I) are useful not only for diagnosis and management of patients with growth hormone (GH)-related disorders but also for assessing nutritional status. We reported population-based references of serum IGF-I in 1996. However, they did not properly reflect data in the transition period from puberty to maturity. The aim of the present study was to re-establish a set of normative data for IGF-I for the Japanese population. The study included 1,685 healthy Japanese subjects (845 males, 840 females) from 0 to 83 years old. Subjects suffering from diseases that could affect IGF-I levels were excluded. Obese or extremely thin adult subjects were also excluded. IGF-I concentrations were determined by commercially available immunoradiometric assays. The reference intervals were calculated using the LMS method. Median IGF-I levels reached 310 ng/mL in males at the age of 14 years and 349 ng/mL in females at the age of 13 years, falling to 124 ng/mL and 103 ng/mL, respectively, by the age of 70 years. The mean pretreatment IGF-1 SD scores in patients with severe GH deficiency (GHD) obtained from the database of the Foundation for Growth Science and from clinical studies for adult GHD were -2.1±1.6 and -4.9±2.5, respectively. The present study established age- and gender-specific normative IGF-I data for the Japanese population and showed the utility of these references for screening patients with severe GHD.

A novel mutation in the GATA3 gene in a family with HDR syndrome (Hypoparathyroidism, sensorineural Deafness and Renal anomaly syndrome).

We report here on a girl and her father with HDR syndrome (Hypoparathyroidism, sensorineural Deafness and Renal anomaly syndrome). The proband, an 11 year-old girl, complained of periodic tetany lasting for 6 years, and also used a hearing aid because of sensorineural hearing impairment. Furthermore, she had hemimegalencephaly, and had been taking an anti-epileptic agent to treat psychomotor seizures for 6 years. Endocrine assessment showed modest hypocalcemia, hyperphosphatemia and hypophosphaturia with lower normal parathyroid hormone concentration, and she had no renal abnormalities. Her father, who was 40 years old at the time of the investigation, had sensorineural hearing impairment, a lower than normal calcium level and normal renal function. Direct sequencing after PCR amplification of genomic DNA revealed a novel insertional mutation (405insC) in the GATA3 gene of both patients. This mutation was hypothesized to disrupt dual zinc fingers as well as one transactivating domain. The present findings lend additional support to the notion that the phenotype cannot be precisely estimated from the genotype in HDR syndrome.

Results of long-term follow-up after treatment of central precocious puberty with leuprorelin acetate: evaluation of effectiveness of treatment and recovery of gonadal function. The TAP-144-SR Japanese Study Group on Central Precocious Puberty.

We evaluated the effect of leuprorelin treatment on adult height (AH) and followed recovery of reproductive function in 63 girls and 13 boys with central precocious puberty (CPP). Mean treatment durations were 3.8 +/- 2.0 and 4.1 +/- 2.5 yr, and posttreatment follow-up durations were 3.5 +/- 1.3 and 2.6 +/- 1.1 yr for girls and boys, respectively. AH was 154.5 +/- 5.7 cm for girls, and 89.5% of girls reached AH within their target height range. For boys, AH was 163.2 +/- 13.0 cm, and 90.9% reached target height range. It appeared that the Bayley-Pinneau method, modified for Japanese children, using a table for advanced bone age (BA), overestimated AH in CPP; and this method, using a table for average BA and projected height for BA, was suitable for prediction of AH in CPP. Menarche or remenarche occurred in 96.8% of girls at the age of 13.1 +/- 1.5 yr. Of 11 girls who contributed urine samples, all seven idiopathic and two organic cases were considered to have ovulation. Serum testosterone levels reached normal adult level in all boys. In conclusion, long-term leuprorelin treatment for children with CPP improved AH and had no adverse effects on recovery of reproductive function.

Cytochrome P450 oxidoreductase gene mutations and Antley-Bixler syndrome with abnormal genitalia and/or impaired steroidogenesis: molecular and clinical studies in 10 patients.

We report on molecular and clinical findings in 10 Japanese patients (four males and six females) from eight families (two pairs of siblings and six isolated cases) with Antley-Bixler syndrome accompanied by abnormal genitalia and/or impaired steroidogenesis. Direct sequencing was performed for all the 15 exons of cytochrome P450 oxidoreductase gene (POR), showing two missense mutations (R457H and Y578C), a 24-bp deletion mutation resulting in loss of nine amino acids and creation of one amino acid (L612_W620delinsR), a single bp insertion mutation leading to frameshift (I444fsX449), and a silent mutation (G5G). R457H has previously been shown to be a pathologic mutation, and computerized modeling analyses indicated that the 15A>G for G5G could disturb an exonic splicing enhancer motif, and the remaining three mutations should affect protein conformations. Six patients were compound heterozygotes, and three patients were R457H homozygotes; no mutation was identified on one allele of the remaining one patient. Clinical findings included various degrees of skeletal features, such as brachycephaly, radiohumeral synostosis, and digital joint contractures in patients of both sexes, normal-to-poor masculinization during fetal and pubertal periods in male patients, virilization during fetal life and poor pubertal development without worsening of virilization in female patients, and relatively large height gain and delayed bone age from the pubertal period in patients of both sexes, together with maternal virilization during pregnancy. Blood cholesterol was grossly normal, and endocrine studies revealed defective CYP17A1 and CYP21A2 activities. The results suggest that Antley-Bixler syndrome with abnormal genitalia and/or impaired steroidogenesis is caused by POR mutations, and that clinical features are variable and primarily explained by impaired activities of POR-dependent CYP51A1, CYP17A1, CYP21A2, and CYP19A1.

Frequencies of spontaneous breast development and spontaneous menarche in Turner syndrome in Japan.

The Growject® database on human GH treatment in Turner syndrome was analyzed in the Turner Syndrome Research Collaboration, and the relationships of the frequencies of spontaneous breast development and spontaneous menarche with karyotype and GH treatment were investigated. One hundred and three cases started GH treatment with 0.5 IU/kg/ week (0.5 IU group), and their dose was increased to 0.35 mg/kg/wk midway through the treatment course. Another 109 cases started GH at a dose of 0.35 mg/kg/wk (0.35 mg group). Spontaneous breast development was observed in 77 (36.3%) of the 212 patients, and spontaneous menarche occurred in 31 patients (14.6%). The frequency of spontaneous breast development was significantly lower in patients with the 45,X karyotype and significantly higher in patients with a structural abnormality of the second X chromosome. The frequency of spontaneous menarche was significantly higher in patients with mosaicism characterized by X monosomy and a cellular line with no structural abnormality of the X chromosome. No significant differences in frequencies of spontaneous breast development and spontaneous menarche were observed between the two dose groups, indicating that GH treatment does not increase the frequency of spontaneous puberty.

Clinical assessment and mutation analysis of Kallmann syndrome 1 (KAL1) and fibroblast growth factor receptor 1 (FGFR1, or KAL2) in five families and 18 sporadic patients.

We report on the clinical and molecular findings in 25 males and three females with Kallmann syndrome (KS) aged 10-53 yr. Ten males were from five families, and the remaining 15 males and three females were apparently sporadic cases. Molecular studies were performed for Kallmann syndrome 1 (KAL1) and fibroblast growth factor receptor 1 (FGFR1, also known as KAL2) by sequence analysis for all the coding exons, by PCR-based deletion analysis, and by fluorescence in situ hybridization (FISH) analysis, showing six novel and two recurrent intragenic KAL1 mutations in seven familial and four sporadic male cases and two novel intragenic FGFR1 mutations in two sporadic male cases. In addition, submicroscopic deletions at Xp22.3 involving VCX-A, STS, KAL1, and OA1 were identified in three familial cases and one sporadic male case affected by a contiguous gene syndrome. Clinical assessment in the 15 males with KAL1 mutations showed normal and borderline olfactory function in two males and right-side dominant renal lesion in seven males, in addition to variable degrees of hypogonadotropic hypogonadism (HH) in all the 15 males and olfactory dysfunction in 13 males. The two males with FGFR1 mutations had HH and anosmia and lacked other features. Clinical features in the remaining 11 cases with no demonstrable KAL1 or FGFR1 mutations included right renal aplasia in one female, cleft palate in one male, cleft palate and perceptive deafness in one male, and dental agenesis and perceptive deafness in one male, in addition to a variable extent of HH and olfactory dysfunction. The results suggest the following: 1) KAL1 mutations might be more prevalent in the Japanese patients than previously estimated in the Caucasian patients and can be associated with apparently normal olfactory function; 2) FGFR1 mutations account for approximately 10% of KS patients, as previously reported in the Caucasian patients, and can result in HH and olfactory dysfunction-only phenotype; and 3) renal aplasia, which is characteristic of KAL1 mutations, and cleft palate and dental agenesis, which are characteristic of FGFR1 mutations, can occur in patients without KAL1 and FGFR1 mutations.

Ovarian function in three female patients with McCune-Albright syndrome with persistent autonomous ovarian activity.

Autonomous ovarian activity persists throughout adolescence in some patients with McCune-Albright syndrome (MAS). There have been few studies of longitudinal assessment of ovarian function in these patients. We investigated the first morning voided urinary gonadotropin and ovarian steroid levels consecutively in three patients aged 3 to 7 years after withdrawal of therapy for precocious puberty. They had the triad of MAS with onset of menses within the first 3 years of life. Excessively elevated urinary estrogen levels with one or two peaks per cycle were found in all patients. In two patients, café-au-lait spots and dysplastic bones were located unilaterally. These two patients showed significantly increased urinary pregnanediol levels, suggesting ovulation, with low levels of gonadotropins in one patient and moderately low levels with an LH surge in the other. Thus, only a unilateral ovary was anticipated to be mutated with persistent autonomous ovarian activity. In the remaining patient with bilateral involvement of tissues, relatively high LH and low FSH levels throughout a cycle were found with no rise in urinary pregnanediol.

Favorable impact of growth hormone treatment on cholesterol levels in turner syndrome.

BACKGROUND: Patients with Turner syndrome (TS) are prone to having metabolic abnormalities, such as obesity, dyslipidemia, hypertension, hyperinsulinemia and type 2 diabetes mellitus, resulting in increased risks of developing atherosclerotic diseases. OBJECTIVE: To determine the effect of growth hormone (GH) therapy on serum cholesterol levels in prepubertal girls with TS enrolled in the Turner syndrome Research Collaboration (TRC) in Japan. PATIENTS AND METHODS: Eighty-one girls with TS were enrolled in the TRC, and their total cholesterol (TC) levels before GH therapy were compared with reported levels of healthy school-aged Japanese girls. TC levels after 1, 2 and 3 yr of GH treatment were available for 28 of the 81 patients with TS. GH was administered by daily subcutaneous injections, 6 or 7 times/wk, with a weekly dose of 0.35 mg/kg body weight. RESULTS: Baseline TC levels revealed an age-related increase in TS that was in contrast to healthy girls showing unchanged levels. During GH therapy, TC decreased significantly after 1 yr of GH treatment and remained low thereafter. CONCLUSIONS: Girls with untreated TS showed an age-related increase in TC that was a striking contrast to healthy girls, who showed unchanged levels. GH therapy in girls with TS brought about a favorable change in TC that indicates the beneficial impact of GH on atherogenic risk.

Dose-dependent changes in body composition during growth hormone (GH) treatment in Japanese patients with adult GH deficiency: a randomized, placebo-controlled trial.

OBJECTIVE: A clinical study was carried out to investigate the efficacy and safety of two doses of GH treatment on adult growth hormone deficiency (AGHD) patients in Japan. Dose-responsiveness between GH doses and changes of body composition was examined. DESIGN: A 24-week, randomized, placebo-controlled, double-blind clinical study in 96 Japanese AGHD patients followed by a 48-week, open-label, long-term study. RESULTS: During the double-blind study, serum insulin-like growth factor (IGF)-I SDS and lean body mass increased and total fat mass and serum total cholesterol decreased similarly in both GH treated groups. Mean changes in IGF-I SDS were 3.63+/-1.67, 1.97+/-1.27, and -0.13+/-0.55 in high-dose (HD) group (0.012 mg/kg/day), low-dose (LD) group (0.006 mg/kg/day), and placebo group, respectively. Trunk fat mass decreased significantly (p<0.001) in HD group and LD group but not in placebo group (mean changes in percent trunk fat mass were -4.6+/-2.6%, -3.0+/-2.5% and 0.2+/-2.1% in HD group, LD group and placebo group, respectively). Serum LDL-cholesterol decreased in both GH treated groups but significantly only in HD group. Statistically significant dose-responsiveness was shown among three groups (p<0.001) with regards to IGF-I SDS, trunk fat mass, total fat mass, and lean body mass. The changes in serum IGF-I SDS, body composition, total cholesterol, and LDL-cholesterol at the end of double-blind study persisted throughout the open-label study. In addition, there was no clinically relevant adverse event during the both studies. CONCLUSIONS: GH treatment significantly improved serum levels of IGF-I and body composition in a dose-responsive manner in Japanese AGHD patients. Total cholesterol and LDL-cholesterol levels also decreased. GH treatment was safe and generally well tolerated.

Adult heights of 258 girls with turner syndrome on low dose of growth hormone therapy in Japan.

Growth hormone (GH) therapy was approved in 1999 for only GH-deficient Turner syndrome (TS) in Japan. It was subsequently approved for all cases of TS regardless of GH secretory status since 1999. The dose of GH is 1.0 u (0.35 mg)/kg/wk at present, but it was 0.5 u (0.175 mg)/kg/wk before 1999. The adult height in patients with TS on the dose of 0.5 u/kg/wk was studied from the report on of Foundation for Growth Science in 2000. GH therapy was registered for 920 cases, and 258 cases reached adult height. The mean adult height was 145.7 cm. The adult height in patients with TS without GH therapy was reported to be 138 cm in Japan. Thus, the height gain by GH treatment was 7.7 cm. The mean age at the start of GH therapy was 12.0 yr old. The mean duration of GH therapy was 5.6 yr. The mean age at the start of estrogen therapy was 17.0 yr old. Patients in Japan were older at the start of GH and estrogen therapy than in the US and Europe at that time. The adult height and gain of height SD were not correlated with age at the start GH therapy in this study. This may be the result of the older age at the start of GH therapy and the low dose of the GH therapy. Patients are beginning to start GH therapy at a much earlier age and the dose has been doubled in Japan. We expect that the recent data concerning adult height in the patients with TS after GH therapy will improve better than this report.

Evaluation of Quality of Life in Children with GH Deficiency and Idiopathic Short Stature Using the Child Behavior Checklist.

The quality of life (QoL) of short children is an important issue that has been studied in Western countries, but not fully in Japan. We assessed the psychosocial profiles of Japanese children with short stature using the Japanese version of the Child Behavior Checklist (CBCL). A higher score in the CBCL means a lower QoL. A total of 116 children with idiopathic short stature (ISS) and 127 children with GH deficiency (GHD), aged 4 to 15 yr, were enrolled in the study. The total CBCL scores of the children in the GHD/ISS group were found to be higher than those of the normal children group. The QoL subscales for social problems and attention problems of the young (4-11 yr) children in the GHD/ISS group were significantly higher than those of the group of children of normal height. The proportion of children with GHD/ISS classified into the borderline/abnormal range was significantly higher than that of normal children. Children with ISS tended to have higher total scores and more subscale problems, and a greater proportion of these children was classified in the borderline/abnormal range than the children with GHD, although the difference was not significant. These results suggest that QoL is impaired in Japanese children due to short stature.

Standardization of blood growth hormone levels measured by different kits using a linear structural relationship.

Accurate and reliable determination of blood growth hormone level is essential in the diagnosis and treatment of short stature children. However, measured levels differed considerably among measurement kits available in Japan until 2003. Therefore, standardization of the measured values was attempted by measuring growth hormone levels in a sample of healthy adult individuals every year using the different kits. A standardization equation was developed for each kit through linear structural relationship with the mean values of the used kits and measured values in each kit as random variables. A Pearson's correlation coefficient between the mean values of all kits and the measured values from each kit was also obtained. Sources for the marked discrepancies amongst the measured values in the different kits were also explored. The obtained values for slopes and intercepts in the equations varied considerably, but the standard values obtained from these equations after the measured values for each kit were transformed into standard values served well as the standard. The standard solutions in the respective measurement kits were found to be the source of variability in the measured values among the kits.

Molecular analysis of the CLCNKB gene in Japanese patients with classic Bartter syndrome.

Deletions or mutations in the gene encoding the basolateral chloride channel CLC-Kb (CLCNKB) cause classic Bartter syndrome (MIM 602023), which is characterized by hypokalemic metabolic alkalosis, hyperreninemic hyperaldosteronism and hypercalciura. These patients are usually diagnosed during infancy or childhood due to failure to thrive and growth retardation. The purpose of this study was to investigate the underlying mutations in Japanese patients with classic Bartter syndrome. Seven Japanese patients from seven different families diagnosed as having classic Bartter syndrome were studied. Analysis of CLCNKB demonstrated a large deletion in two patients, a partial deletion in one patient and two mutations (DeltaL130 in exon 4 and W610X in exon 16) in the remaining four patients. DeltaL130 is a novel mutation, but W610X was previously reported in three unrelated Japanese patients. Six out of the seven patients were diagnosed due to typical characteristics of classic Bartter syndrome such as failure to thrive and poor weight gain however, one patient was asymptomatic with mild hypokalemia. In conclusion, we identified a novel mutation of the CLCNKB gene, DeltaL130. We did not determine whether the W610X mutation in our patients was from a common ancestor or if this mutation is frequent in Japan.