Asfotase alfa for infants and young children with hypophosphatasia: 7 year outcomes of a single-arm, open-label, phase 2 extension trial.

BACKGROUND: Our previous phase 2, open-label study of 11 infants and young children with life-threatening perinatal or infantile hypophosphatasia showed 1 year safety and efficacy of asfotase alfa, an enzyme replacement therapy. We aimed to report the long-term outcomes over approximately 7 years of treatment. METHODS: We did a prespecified, end of study, 7 year follow-up of our single-arm, open-label, phase 2 trial in which children aged 3 years or younger with life-threatening perinatal or infantile hypophosphatasia were recruited from ten hospitals (six in the USA, two in the UK, one in Canada, and one in the United Arab Emirates). Patients received asfotase alfa (1 mg/kg three times per week subcutaneously, adjusted to 3 mg/kg three times per week if required) for up to 7 years (primary treatment period plus extension phase) or until the product became commercially available; dosage adjustments were made at each visit according to changes in the patient's weight. The primary objectives of this extension study were to assess the long-term tolerability of asfotase alfa, defined as the number of patients with one or more treatment-emergent adverse events, and skeletal manifestations associated with hypophosphatasia, evaluated using the Radiographic Global Impression of Change (RGI-C) scale (-3 indicating severe worsening, and +3 complete or near-complete healing). Respiratory support, growth, and cognitive and motor functions were also evaluated. All efficacy and safety analyses were done in all patients who received any asfotase alfa (full-analysis population). This study and extension phase are registered with ClinicalTrials.gov, number NCT01205152, and EudraCT, number 2009-009369-32. FINDINGS: 11 participants were recruited between Oct 6, 2008, and Dec 4, 2009. Ten patients completed a 6 month treatment period and entered the extension phase; nine received asfotase alfa for at least 6 years and completed the study, with four being treated for more than 7 years. Skeletal healing was sustained over 7 years of treatment; all evaluable patients had RGI-C scores of at least +2 at year 6 (n=9; median score +2·0 [range 2·0-3·0]) and year 7 (n=7; median score +2·3 [2·0-3·0]). No patient who completed the study required respiratory support after year 4. Weight Z scores improved to within normal range from year 3 to study end; length or height Z scores improved but remained below normal. Age-equivalent scores on gross motor, fine motor, and cognitive subscales of the Bayley Scales of Infant and Toddler Development also improved. All 11 patients had at least one treatment-emergent adverse event. The most common adverse events were pyrexia (eight [73%] of 11 patients), upper respiratory tract infection (eight [73%]), craniosynostosis (seven [64%]), and pneumonia (seven [64%]). Serious adverse events related to asfotase alfa occurred in three (27%) patients (severe chronic hepatitis; moderate immediate post-injection reaction; and severe craniosynostosis with severe conductive deafness). INTERPRETATION: Patients with perinatal or infantile hypophosphatasia treated with asfotase alfa for up to 7 years showed early, sustained improvements in skeletal mineralisation. Respiratory function, growth, and cognitive and motor function also improved, and asfotase alfa was generally well tolerated. FUNDING: Alexion Pharmaceuticals, Inc.

Effects of thyroxine exposure on the Twist 1 +/- phenotype: A test of gene-environment interaction modeling for craniosynostosis.

BACKGROUND: Craniosynostosis, the premature fusion of one or more of the cranial sutures, is estimated to occur in 1:1800 to 2500 births. Genetic murine models of craniosynostosis exist, but often imperfectly model human patients. Case, cohort, and surveillance studies have identified excess thyroid hormone as an agent that can either cause or exacerbate human cases of craniosynostosis. METHODS: Here we investigate the influence of in utero and in vitro exogenous thyroid hormone exposure on a murine model of craniosynostosis, Twist 1 +/-. RESULTS: By 15 days post-natal, there was evidence of coronal suture fusion in the Twist 1 +/- model, regardless of exposure. With the exception of craniofacial width, there were no significant effects of exposure; however, the Twist 1 +/- phenotype was significantly different from the wild-type control. Twist 1 +/- cranial suture cells did not respond to thyroxine treatment as measured by proliferation, osteogenic differentiation, and gene expression of osteogenic markers. However, treatment of these cells did result in modulation of thyroid associated gene expression. CONCLUSION: Our findings suggest the phenotypic effects of the genetic mutation largely outweighed the effects of thyroxine exposure in the Twist 1 +/- model. These results highlight difficultly in experimentally modeling gene-environment interactions for craniosynostotic phenotypes. Birth Defects Research (Part A) 106:803-813, 2016. © 2016 Wiley Periodicals, Inc.

Craniosynostosis Following Fetal Methotrexate Exposure.

Methotrexate (MTX) is an antimetabolite, folic acid antagonist that inhibits purine nucleotide production, DNA synthesis, and cellular proliferation. Despite widespread therapeutic uses, MTX remains a potent teratogen. Methotrexate embryopathy encompasses multiorgan system dysfunction, including intrauterine growth restriction as well as cardiac, craniofacial, renal, genital, and skeletal abnormalities. Effects of MTX exposure on fetal development continue to be described. This series of 4 patients with MTX-associated craniosynostosis represents the largest published association between prenatal MTX exposure and premature cranial suture closure.

Recombinant human bone morphogenetic protein-2-induced craniosynostosis and growth restriction in the immature skeleton.

BACKGROUND: Recombinant human bone morphogenetic protein-2 (rhBMP-2) delivered on an absorbable collagen sponge is a U.S. Food and Drug Administration-approved therapy effective at generating bone formation. In pediatric patients for whom other therapeutic options have been exhausted, rhBMP-2 is used off-label to address problematic bony defects. In the skeletally immature patient, the safety of rhBMP-2 therapy remains uncertain. Experiments are needed that investigate the effect of rhBMP-2 on growth and development in clinically relevant models. METHODS: Ten juvenile rabbits underwent creation of a parietal skull defect that was treated with either 0.2 mg/cc rhBMP-2/absorbable collagen sponge or a neutral buffer solution/absorbable collagen sponge. Amalgam markers were placed at suture confluences to track suture separation and skull growth. Cranial growth was assessed radiographically at 10, 25, 42, and 84 days of age. Means and standard deviations for the various craniofacial growth variables were calculated and compared. Mean differences were considered significant for values of p < 0.05. At 84 days, sutures were analyzed by means of micro-computed tomographic scanning and histologic staining. RESULTS: Treatment with rhBMP-2 resulted in fusion of the coronal sutures bilaterally, with variable fusion of the sagittal suture by cephalometric, radiographic, and histologic analysis. There were statistically significant changes to coronal suture growth, sagittal suture growth, skull height, craniofacial length, and intracranial volume (p < 0.05). CONCLUSIONS: The use of rhBMP-2 in this juvenile animal model resulted in skeletal changes that may be undesirable in a clinical setting. The appearance of these fused sutures suggested a direct effect of rhBMP-2. Further work is required to limit the effect of rhBMP-2 to the target defect when used in the immature skeleton.

Etiological heterogeneity and clinical characteristics of metopic synostosis: Evidence from a tertiary craniofacial unit.

Metopic synostosis (MS) accounts for approximately 10-15% of all craniosynostosis and is etiologically heterogeneous. This study aimed to examine the causes of MS, as observed in a tertiary craniofacial unit. We reviewed the case notes of 110 children with a diagnosis of MS, attending the craniofacial unit in Oxford between 1991 and 2008. Our results showed 38 children (38/110 or 34.6%) who had at least one additional structural abnormality or had a known syndromic diagnosis were classed as having syndromic MS. Chromosomal abnormalities were noted in 8/38 (21.4%) children: mosaic marker chromosome 2, 9p deletion (2/8), 11q deletion, 12pter deletion and duplication of 15q25 with other additional chromosomal abnormalities (3/8). Other syndromic diagnoses included Silver-Russell syndrome and Greig cephalopolysyndactyly. Prenatal exposure to sodium valproate (VPA) was noted in 8/110 children (7.8%), with the dose of the VPA being >or=1,000 mg/day in all cases. Other prenatal exposures reported in this study were: maternal diabetes (6/110), enoxaparin for hypercoagulable state (1/110), and thyroxine (1/110). The majority of patients (72/110 or 65.4%) had nonsyndromic MS. Speech delay was present in 11 children with nonsyndromic MS (11/72 or 15.3%) and 10 children with syndromic MS (10/38 or 26.3%). We conclude that approximately two-thirds of all MS is nonsyndromic. Prenatal exposure to VPA is a common cause of MS. Maternal diabetes, not previously linked to MS, was noted in 5.5% of cases. Chromosomal abnormalities account for about 6% of MS. An increased risk of speech delay is seen with both the syndromic and nonsyndromic forms.

Effects of recombinant human bone morphogenetic protein-2 on midsagittal sutural bone formation during expansion.

INTRODUCTION: The goal of this study was to evaluate whether human recombinant bone morphogenetic protein-2 (rhBMP-2) enhances sutural bone formation or causes premature sutural fusion. METHODS: Thirty 6-week-old rabbits underwent midsagittal sutural expansion. The animals were randomly assigned to receive 0 (control), 0.1 mg per milliliter, or 0.4 mg per milliliter of rhBMP-2, delivered by an absorbable collagen sponge placed over the suture. A 100-g constant force was delivered for 33 days by using a nickel-titanium spring to expand the suture between 2 miniscrew implants anchored in the frontal bone. At days 10, 20, and 30, sutural separation was evaluated and modeled over time as polynomials by using multilevel statistical procedures. Bone formation and sutural gaps were analyzed histomorphometrically between days 10 and 20 and days 20 and 30. RESULTS: The control group showed significantly greater overall sutural bone formation than did the 2 rhBMP-2 groups. Over time, bone formation decreased significantly in all groups. Between days 10 and 20, the 0.4 mg per milliliter group produced significantly more (58%) bone than did the 0.1 mg per milliliter group; there were no significant differences in bone formation between the 2 experimental groups between days 20 and 30. Both 0.1 and 0.4 mg per milliliter of rhBMP-2 in the absorbable collagen sponge caused premature fusion by forming a bony bridge connecting the ectocranial aspect of the sutural margins. Premature fusion significantly reduced sutural separation between 10 and 30 days (to 56% and 62% of control values for the 0.1 and 0.4 mg per milliliter groups, respectively). There were no significant differences in sutural separation between the 0.1 and 0.4 mg per milliliter groups. CONCLUSIONS: Compared with the 0.1 mg per milliliter group, 0.4 mg per milliliter of rhBMP-2 accelerated sutural bone formation between days 10 and 20. After 10 to 20 days, rhBMP-2 in the absorbable collagen sponge caused premature sutural fusion, despite the constant expansion forces.

Fetal sodium valproate exposure causes Baller-Gerold syndrome phenotype: both phenotypes in the same family.

Baller-Gerold syndrome (BGS) is characterized by craniosynostosis and preaxial upper-limb malformations, and it has an autosomal recessive inheritance. Valproate syndrome occurs after exposure to valproic acid in utero, and is characterized by trigonocephaly. Both syndromes can also present with other malformations. Herein, we report a female newborn and her brother who both had a history of fetal exposure to maternal anti-epileptic drugs, especially sodium valproate. On physical examination of the female patient, craniosynostosis, trigonocephaly, right radius aplasia and hypoplastic thumb, and cardiac and renal malformations were determined, and she was diagnosed with BGS phenotype. The brother's examination revealed trigonocephaly, polymastia and hypospadias, and he was diagnosed with valproate syndrome. Based on these patients, we aimed to add further evidence in the literature indicating that the use of sodium valproate alone and in combination with other anti-epileptic drugs throughout pregnancy can increase the risk of serious fetal congenital malformations depending on the doses.

Induced premaxillary suture fusion: class III malocclusion model.

The etiology of class III malocclusion remains unknown. The present study investigates the relationship between craniofacial morphology and premaxillary suture fusion to test the hypothesis that class III malocclusion may be related to premaxillary suture fusion. Cyanoacrylate was applied to immobilize the left premaxillary suture in the experimental group. Sham surgeries in rats were used for controls. Dental impressions and radiographs were taken before and after surgery for comparison of craniofacial differences between groups. Overall cranial base lengths, craniofacial widths, and craniofacial angulations related to the anterior base showed significant differences between groups. At the end of the experiment, the growth of the snout in the experimental group was inhibited and deviated to the treated side, while no obvious change was seen in the control group. The results show that induced premaxillary suture fusion can affect craniofacial morphology and indicate that premature premaxillary suture fusion may result in class III malocclusion.

First-trimester use of selective serotonin-reuptake inhibitors and the risk of birth defects.

BACKGROUND: The risk of birth defects after antenatal exposure to selective serotonin-reuptake inhibitors (SSRIs) remains controversial. METHODS: We assessed associations between first-trimester maternal use of SSRIs and the risk of birth defects among 9849 infants with and 5860 infants without birth defects participating in the Slone Epidemiology Center Birth Defects Study. RESULTS: In analyses of defects previously associated with SSRI use (involving 42 comparisons), overall use of SSRIs was not associated with significantly increased risks of craniosynostosis (115 subjects, 2 exposed to SSRIs; odds ratio, 0.8; 95% confidence interval [CI], 0.2 to 3.5), omphalocele (127 subjects, 3 exposed; odds ratio, 1.4; 95% CI, 0.4 to 4.5), or heart defects overall (3724 subjects, 100 exposed; odds ratio, 1.2; 95% CI, 0.9 to 1.6). Analyses of the associations between individual SSRIs and specific defects showed significant associations between the use of sertraline and omphalocele (odds ratio, 5.7; 95% CI, 1.6 to 20.7; 3 exposed subjects) and septal defects (odds ratio, 2.0; 95% CI, 1.2 to 4.0; 13 exposed subjects) and between the use of paroxetine and right ventricular outflow tract obstruction defects (odds ratio, 3.3; 95% CI, 1.3 to 8.8; 6 exposed subjects). The risks were not appreciably or significantly increased for other defects or other SSRIs or non-SSRI antidepressants. Exploratory analyses involving 66 comparisons showed possible associations of paroxetine and sertraline with other specific defects. CONCLUSIONS: Our findings do not show that there are significantly increased risks of craniosynostosis, omphalocele, or heart defects associated with SSRI use overall. They suggest that individual SSRIs may confer increased risks for some specific defects, but it should be recognized that the specific defects implicated are rare and the absolute risks are small.

Use of selective serotonin-reuptake inhibitors in pregnancy and the risk of birth defects.

BACKGROUND: Information regarding the safety of selective serotonin-reuptake inhibitors (SSRIs) in human pregnancy is sparse. Concern has been raised about the risk of congenital heart defects associated with the use of SSRIs in pregnancy. METHODS: We obtained data on 9622 case infants with major birth defects and 4092 control infants born from 1997 through 2002 from the National Birth Defects Prevention Study. Case infants were ascertained through birth-defects surveillance systems in eight U.S. states; controls were selected randomly from the same geographic areas. Mothers completed a standardized telephone interview regarding exposure to potential risk factors, including medications, before and during pregnancy. Exposure to SSRIs was defined as treatment with any SSRI from 1 month before to 3 months after conception. Birth defects were assigned to 26 categories and subcategories. RESULTS: There were no significant associations between maternal use of SSRIs overall during early pregnancy and congenital heart defects or most other categories or subcategories of birth defects. Maternal SSRI use was associated with anencephaly (214 infants, 9 exposed; adjusted odds ratio, 2.4; 95% confidence interval [CI], 1.1 to 5.1), craniosynostosis (432 infants, 24 exposed; adjusted odds ratio, 2.5; 95% CI, 1.5 to 4.0), and omphalocele (181 infants, 11 exposed; adjusted odds ratio, 2.8; 95% CI, 1.3 to 5.7). CONCLUSIONS: Maternal use of SSRIs during early pregnancy was not associated with significantly increased risks of congenital heart defects or of most other categories of birth defects. Associations were observed between SSRI use and three types of birth defects, but the absolute risks were small, and these observations require confirmation by other studies.

Noggin inhibits postoperative resynostosis in craniosynostotic rabbits.

UNLABELLED: Inhibition of bone formation after surgery to correct craniosynostosis would alleviate the need for secondary surgeries and decrease morbidity and mortality. This study used a single dose of Noggin protein to prevent resynostosis and improve postoperative outcomes in a rabbit model of craniosynostosis. INTRODUCTION: Craniosynostosis is defined as the premature fusion of one or more of the cranial sutures, which causes secondary deformations of the cranial vault, cranial base, and brain. Current surgical intervention involves extirpation of the fused suture to allow unrestricted brain growth. However, resynostosis of the extirpated regions often occurs. Several bone morphogenetic proteins (BMPs), well-described inducers of ossification, are involved in bone healing. This study tested the hypothesis that a postoperative treatment with Noggin, an extracellular BMP inhibitor, can inhibit resynostosis in a rabbit model of human familial nonsyndromic craniosynostosis. MATERIALS AND METHODS: Thirty-one New Zealand white rabbits with bilateral coronal suture synostosis were divided into three groups: (1) suturectomy controls (n = 13); (2) suturectomy with BSA in a slow-resorbing collagen vehicle, (n = 8); and (3) suturectomy with Noggin in a slow-resorbing collagen vehicle (n = 10). At 10 days of age, a 3 x 15-mm coronal suturectomy was performed. The sites in groups 2 and 3 were immediately filled with BSA-loaded gel or Noggin-loaded gel, respectively. Serial 3D-CT scan reconstructions of the defects and standard radiographs were obtained at 10, 25, 42, and 84 days of age, and the sutures were harvested for histological analysis. RESULTS: Radiographic analysis revealed that Noggin-treated animals had significantly greater coronal suture marker separation by 25 days and significantly greater craniofacial length at 84 days of age compared with controls. 3D-CT analysis revealed that Noggin treatment led to significantly greater defect areas through 84 days and to increased intracranial volumes at 84 days of age compared with other groups. Histological analysis supported CT data, showing that the untreated and BSA-treated groups had significant healing of the suturectomy site, whereas the Noggin-treated group had incomplete wound healing. CONCLUSIONS: These data support our hypothesis that inhibition of BMP activity using Noggin may prevent postoperative resynostosis in this rabbit model. These findings also suggest that Noggin therapy may have potential clinical use to prevent postoperative resynostosis in infants with craniosynostosis.

Fetal exposure to sodium valproate associated with Baller-Gerold syndrome: case report and review of the literature.

CASE REPORT: We report three patients with a history of maternal valproate use during pregnancy who presented with a combination of metopic suture synostosis and upper limb malformations, which could be diagnosed as Baller-Gerold syndrome (BGS). The patients underwent surgical treatment for the craniofacial deformity, during which standard frontocranial reconstruction was performed. REVIEW OF THE LITERATURE: Only 32 patients have been reported in the world literature and these cases support the emerging view that BGS is not a distinct syndrome, but should instead be considered to be an heterogeneous phenotype with variable etiology. CONCLUSIONS: Our case series suggests for the first time that fetal sodium valproate exposure may also cause this phenotype.

Maternal drug use, fertility problems, and infant craniostenosis.

OBJECTIVE: To test the hypothesis that maternal drug use or treatment for infertility is related to the occurrence of infant craniostenosis. DESIGN AND MATERIAL: Maternal drug use and infertility treatment were studied in 398 cases of craniostenosis, identified from various Swedish health registers. Exposure information was ascertained in early pregnancy, and comparisons after adjustment for some confounders were made with all infants born. In order to validate some findings, data from the Central-East France Registry were studied for first trimester drug exposure in 235 infants, and use of ovarian stimulation in 315 infants with craniostenosis. RESULTS: A statistically significant association between maternal use of anticonvulsants and infant craniostenosis was found (risk ratio [Swedish data], 6.9; 95% confidence interval, 1.10 to 7.94). With the Swedish data, an association was found with three nitrosatable drugs (risk ratio, 3.4; 95% confidence interval, 1.10 to 7.94), previously associated with the occurrence of craniostenosis, but this was based on only five exposures, and no such exposure occurred in the French data set. No association with subfertility (odds ratio, 0.72; 95% confidence interval, 0.60 to 1.86) or infertility treatment (odds ratio, 1.06; 95% confidence interval, 0.60 to 1.87) was found in the Swedish data and no statistically significant increase in the use of ovulation stimulation in the French data. CONCLUSIONS: A strong association was found between the maternal use of anticonvulsants and infant craniostenosis, and a tentative association was found with the use of nitrofurantoin and two other nitrosatable drugs. There was no association with maternal subfertility or infertility treatment.

Raman imaging demonstrates FGF2-induced craniosynostosis in mouse calvaria.

Craniosynostosis is a severe craniofacial disease where one or more sutures, the fibrous tissue that lies between the cranial bones, fuses prematurely. Some craniosynostosis syndromes are known to be caused by mutations in fibroblast growth factor (FGF) receptors. Mutated FGF receptors are thought to cause constitutive signaling. In this study, heparin acrylic beads released fibroblast growth factor 2 (FGF2) to mimic constitutive signaling by mutated receptors, delivering FGF2 in addition to already existing normal tissue amounts. Fetal day 18.5 mouse sutures were treated with FGF2-soaked beads and cultured in serum free media for 48 h. We have shown previously that this treatment leads to fusion and increased Msx2 expression, but here we use near-infrared Raman imaging to simultaneously examine the mineral components and matrix components of cranial tissue while providing light microscopic spatial information. FGF2-treated mouse sutures show increased v1 phosphate and v1 carbonate bandwidths, indicating a slightly chemically modified mineral being rapidly deposited. In addition, FGF2-treated mouse sutures show a marked increase in mineral-to-matrix ratios compared to control mouse sutures, typical of increased mineralization.

Craniosynostosis and fetal exposure to sodium valproate.

OBJECT: Fetal valproate syndrome affects one in 10 children born to mothers who ingest sodium valproate regularly during pregnancy. It has been described as producing a combination of typical dysmorphic features and major organ system anomalies. Trigonocephaly is caused by premature fusion of the metopic suture and has not previously been described as a typical feature of the syndrome. The authors reviewed the cases of 2,220 children with craniosynostosis to examine the effect of maternal sodium valproate use on the fetus. METHODS: Case files of all 2,220 children were reviewed. The type and severity of each patient's craniosynostosis was assessed. Information about maternal health and medication use was obtained, and family interviews were conducted. Children underwent mental development assessment performed using standard tests both pre- and postoperatively. Detailed maternal health information was obtained in 1,676 cases. Of these, 17 mothers were found to have undergone regular treatment with sodium valproate monotherapy at the time of their pregnancies. No other antiepileptic medical regimen was found. All 17 children exhibited trigonocephaly. These patients' intelligence quotients (JQs) at the time of the most recent follow-up examination ranged from 45 to 100, with a mean of 75; IQs were significantly higher in patients who underwent surgery before reaching 6 months of age. CONCLUSIONS: Ideally any pregnancy in a woman being treated for epilepsy should be planned, and both an obstetrician and a neurologist should be consulted. In children born with fetal valproate syndrome, it is important to be aware of the possibility of metopic suture synostosis, which we believe should be considered part of the syndrome, because early surgical intervention may improve cognitive outcome.

[Metopic suture craniosynostosis: sodium valproate teratogenic effect. Case report]. / Cranioestenose da sutura metópica: efeito teratogênico do valproato de sódio. Relato de caso.

OBJECTIVE: the aim of this report is to warn that sodium valproate used during pregnancy can produce craniosynostosis in the newborn, particularly trigonocephaly. METHOD: we describe a case of trigonocephaly in a six month-old girl, daughter of a young non-smoker couple, whose mother had used phenobarbital 100 mg daily and sodium valproate 500 mg twice daily during the whole pregnancy. We also review current literature about this topic. RESULT: bone sclerosis over the metopic suture was confirmed during surgery. Bibliographical review yields previous reports on valproate teratogenicity, mainly determining metopic suture craniosynostosis. CONCLUSION: sodium valproate used during pregnancy can produce craniosynostosis by teratogenic effect, specially trigonocephaly (premature fusion of metopic suture).