The international X-linked hypophosphataemia (XLH) registry (NCT03193476) : rationale for and description of an international, observational study

Background X-linked hypophosphataemia (XLH) is a rare, hereditary, progressive and lifelong phosphate wasting disorder characterised by pathological elevations in fibroblast growth factor (FGF) 23 concentration and activity; XLH has an incidence of approximately 1 in 20-25,000 individuals. Excess FGF23 activity leads to increased phosphate excretion in the kidneys - mediated by downregulation of renal tubular phosphate transporters - and reduced phosphate absorption in the intestines - due to impaired vitamin D activation. This results in impaired bone growth and mineralisation, short and disproportionate stature, leg bowing, musculoskeletal pain, spontaneous dental abscesses, rickets, and osteomalacia. The spectrum of manifestations differs between paediatric and adult patients. Those involved in the treatment of this condition face many challenges, including a lack of robust natural history and demographic data. This multicentre, international, rare-disease patient registry (XLH Registry) was established to address the paucity of data in XLH and to help inform future clinical practice. Results The XLH Registry collects standard diagnostic and monitoring practice data, including (where applicable) diagnosis and disease progression history, treatment regimens and family history; the protocol does not mandate any interventions or clinical assessments. The XLH Registry aims to recruit 1200 paediatric and adult patients with XLH over 10 years, and several data analyses and peer-reviewed publications are expected to be generated throughout this period. A post-authorisation safety study for Bburosumab, for which the registry Sponsor is the marketing authorisation holder, will be nested as a sub-study within the XLH Registry via a subsequent protocol amendment. Conclusion The data collected within this rare-disease patient registry will be utilised to synthesise real-world evidence to inform the management of XLH, to improve the quality of life and standard of care of patients living with this rare debilitating disease.Peer reviewe

The international X-linked hypophosphataemia (XLH) registry (NCT03193476): rationale for and description of an international, observational study

Abstract Background X-linked hypophosphataemia (XLH) is a rare, hereditary, progressive and lifelong phosphate wasting disorder characterised by pathological elevations in fibroblast growth factor (FGF) 23 concentration and activity; XLH has an incidence of approximately 1 in 20–25,000 individuals. Excess FGF23 activity leads to increased phosphate excretion in the kidneys – mediated by downregulation of renal tubular phosphate transporters – and reduced phosphate absorption in the intestines – due to impaired vitamin D activation. This results in impaired bone growth and mineralisation, short and disproportionate stature, leg bowing, musculoskeletal pain, spontaneous dental abscesses, rickets, and osteomalacia. The spectrum of manifestations differs between paediatric and adult patients. Those involved in the treatment of this condition face many challenges, including a lack of robust natural history and demographic data. This multicentre, international, rare-disease patient registry (XLH Registry) was established to address the paucity of data in XLH and to help inform future clinical practice. Results The XLH Registry collects standard diagnostic and monitoring practice data, including (where applicable) diagnosis and disease progression history, treatment regimens and family history; the protocol does not mandate any interventions or clinical assessments. The XLH Registry aims to recruit 1200 paediatric and adult patients with XLH over 10 years, and several data analyses and peer-reviewed publications are expected to be generated throughout this period. A post-authorisation safety study for Bburosumab, for which the registry Sponsor is the marketing authorisation holder, will be nested as a sub-study within the XLH Registry via a subsequent protocol amendment. Conclusion The data collected within this rare-disease patient registry will be utilised to synthesise real-world evidence to inform the management of XLH, to improve the quality of life and standard of care of patients living with this rare debilitating disease

FGF23 and its role in X-linked hypophosphatemia-related morbidity

Background: X-linked hypophosphatemia (XLH) is an inherited disease of phosphate metabolism in which inactivating mutations of the Phosphate Regulating Endopeptidase Homolog, X-Linked (PHEX) gene lead to local and systemic effects including impaired growth, rickets, osteomalacia, bone abnormalities, bone pain, spontaneous dental abscesses, hearing difficulties, enthesopathy, osteoarthritis, and muscular dysfunction. Patients with XLH present with elevated levels of fibroblast growth factor 23 (FGF23), which is thought to mediate many of the aforementioned manifestations of the disease. Elevated FGF23 has also been observed in many other diseases of hypophosphatemia, and a range of animal models have been developed to study these diseases, yet the role of FGF23 in the pathophysiology of XLH is incompletely understood. Methods: The role of FGF23 in the pathophysiology of XLH is here reviewed by describing what is known about phenotypes associated with various PHEX mutations, animal models of XLH, and non-nutritional diseases of hypophosphatemia, and by presenting molecular pathways that have been proposed to contribute to manifestations of XLH. Results: The pathophysiology of XLH is complex, involving a range of molecular pathways that variously contribute to different manifestations of the disease. Hypophosphatemia due to elevated FGF23 is the most obvious contributor, however localised fluctuations in tissue non-specific alkaline phosphatase (TNAP), pyrophosphate, calcitriol and direct effects of FGF23 have been observed to be associated with certain manifestations. Conclusions: By describing what is known about these pathways, this review highlights key areas for future research that would contribute to the understanding and clinical treatment of non-nutritional diseases of hypophosphatemia, particularly XLH.Peer reviewe

Estimation of Reduction in Influenza Vaccine Effectiveness Due to Egg-Adaptation Changes—Systematic Literature Review and Expert Consensus

Background: Influenza vaccines are the main tool to prevent morbidity and mortality of the disease; however, egg adaptations associated with the choice of the manufacturing process may reduce their effectiveness. This study aimed to estimate the impact of egg adaptations and antigenic drift on the effectiveness of trivalent (TIV) and quadrivalent (QIV) influenza vaccines. Methods: Nine experts in influenza virology were recruited into a Delphi-style exercise. In the first round, the experts were asked to answer questions on the impact of antigenic drift and egg adaptations on vaccine match (VM) and influenza vaccine effectiveness (IVE). In the second round, the experts were presented with the data from a systematic literature review on the same subject and aggregated experts’ responses to round one questions. The experts were asked to review and confirm or amend their responses before the final summary statistics were calculated. Results: The experts estimated that, across Europe, the egg adaptations reduce, on average, VM to circulating viruses by 7–21% and reduce IVE by 4–16%. According to the experts, antigenic drift results in a similar impact on VM (8–24%) and IVE (5–20%). The highest reduction in IVE was estimated for the influenza virus A(H3N2) subtype for the under 65 age group. When asked about the frequency of the phenomena, the experts indicated that, on average, between the 2014 and 19 seasons, egg adaptation and antigenic drift were significant enough to impact IVE that occurred in two and three out of five seasons, respectively. They also agreed that this pattern is likely to reoccur in future seasons. Conclusions: Expert estimates suggest there is a potential for 9% on average (weighted average of “All strains” over three age groups adjusted by population size) and up to a 16% increase in IVE (against A(H3N2), the <65 age group) if egg adaptations that arise when employing the traditional egg-based manufacturing process are avoided

Commercial impact of adding real-world evidence to clinical trials at regulatory approval: A Markovian-like transition model

Regulatory use of real-world evidence (RWE) has been recognised as a useful supplement to clinical trial evidence and could benefit patients by reducing time to treatment. However, commercial benefits have not been documented. The aim was to determine commercial impact of regulatory RWE, using ambrisentan as an illustrative example. A Markovian-like transition model was constructed to simulate the drug development workflow across a simulation time of t = 20 years. RWE was assumed to be incorporated at pII - pIII and pII - pIII - pIV, and its multiplicative median transition rate was determined by biopharma expert opinion. Each model was subjected to ‘with’ and ‘without’ RWE rates. Commercial impact was estimated using potential decrease in time to launch. Time to first medicine adoption and potential lives saved were also estimated. Based on cumulative first prescriptions for ambrisentan among pulmonary arterial hypertension patients (N = 487), in comparison to standard drug development, RWE incorporation has the potential to expedite first medicine adoption by 10.4 weeks. The duration of market launch was estimated at 2.5–3.0 years earlier than standard, and approximately 9% of patients would benefit in survival. Potential earnings for an earlier launch would be GBP £43,597.86 per patient, with launch being brought forward from 2009 to 2007. Regulatory RWE has the potential to increase overall survival rates and potential earnings by reducing time to launch. This study provides further support for industry efforts to generate RWE in time for regulatory approval.</p

Successful Vaginal Delivery of a Male Infant During Extracorporeal Carbon Dioxide Removal: A Case Report

Extracorporeal carbon dioxide removal (ECCO2R) has become an effective strategy for the support of newborn infants with severe respiratory failure, but the survival rate for children and adults undergoing this procedure is only 50%. We initiated ECCO2R in a 20 year old, gravida 3, white female who developed severe respiratory distress after seeking treatment for a fever of four days duration and a nonproductive cough. Uterine contractions began shortly after ECCO2R was initiated. Nine hours later a male infant was delivered vaginally. Both mother and baby survived. To our knowledge, ECCO2R had never been used before to support a woman during labor and vaginal delivery

A simple core dataset for triglyceride-induced acute pancreatitis

ObjectiveThe objective of this study is to generate a core clinical dataset (CD) containing the minimum acceptable amount of information that should be collected for each patient presenting with triglyceride-induced acute pancreatitis within global treatment centres or sites.MethodThe Jandhyala Method, including systematic literature review and SMART interviews, was used to observe expert opinion from ten leaders in the treatment of triglyceride-induced acute pancreatitis (TG-IAP) across the US and EU.ResultsUsing the PRISMA Literature Review Protocol, data were extracted from 123 of the 6718 identified studies. A total of 243 items were identified from the data extracted from these studies and, combined with the unique items coded from the Awareness Round (1) survey, formed the Consensus Round (2) survey. One hundred and ninety-five of the 243 items (80%) met the consensus threshold and were included for appraisal in the SMART interview phase. A total of 109 items were agreed to form part of the current clinical diagnostic and monitoring procedure by all experts once the weights across all the stakeholder disciplines were balanced to eliminate bias. These items were further condensed to form the core dataset, comprising a total of 87 items.ConclusionOnce validated and adopted, the TG-IAP CD will improve the overall management of patients with TG-IAP by speeding up diagnosis and detecting changes in disease severity and subsequent disease progression, informing personalized patient management plans, and improving patient outcomes

FGF23 and its role in X-linked hypophosphatemia-related morbidity

BACKGROUND: X-linked hypophosphatemia (XLH) is an inherited disease of phosphate metabolism in which inactivating mutations of the Phosphate Regulating Endopeptidase Homolog, X-Linked (PHEX) gene lead to local and systemic effects including impaired growth, rickets, osteomalacia, bone abnormalities, bone pain, spontaneous dental abscesses, hearing difficulties, enthesopathy, osteoarthritis, and muscular dysfunction. Patients with XLH present with elevated levels of fibroblast growth factor 23 (FGF23), which is thought to mediate many of the aforementioned manifestations of the disease. Elevated FGF23 has also been observed in many other diseases of hypophosphatemia, and a range of animal models have been developed to study these diseases, yet the role of FGF23 in the pathophysiology of XLH is incompletely understood. METHODS: The role of FGF23 in the pathophysiology of XLH is here reviewed by describing what is known about phenotypes associated with various PHEX mutations, animal models of XLH, and non-nutritional diseases of hypophosphatemia, and by presenting molecular pathways that have been proposed to contribute to manifestations of XLH. RESULTS: The pathophysiology of XLH is complex, involving a range of molecular pathways that variously contribute to different manifestations of the disease. Hypophosphatemia due to elevated FGF23 is the most obvious contributor, however localised fluctuations in tissue non-specific alkaline phosphatase (TNAP), pyrophosphate, calcitriol and direct effects of FGF23 have been observed to be associated with certain manifestations. CONCLUSIONS: By describing what is known about these pathways, this review highlights key areas for future research that would contribute to the understanding and clinical treatment of non-nutritional diseases of hypophosphatemia, particularly XLH.status: publishe

A simple core dataset and disease severity score for hereditary transthyretin (ATTRv) amyloidosis

Hereditary transthyretin (ATTRv) amyloidosis is a progressive multisystemic disease of adult-onset that arises from an inherited mutation in the transthyretin gene. Currently available disease severity and progression evaluation tools only cover one single organ or system, impacting data collection uniformity and its use in clinical settings. The Jandhyala Method, including a systematic literature review and SMART interviews, was used to observe expert opinion from eight leaders in the treatment of ATTRv across Europe. The aim was to propose a multidisciplinary core dataset (CD) and disease severity scoring (DSS) tools. The multidisciplinary team of experts identified 140 indicators that form part of the standard diagnostic and monitoring practice (SDMP) and should be collected as the ATTRv CD. Thirty-one (22%) of these indicators informed disease severity and comprised the ATTRv DSS, whilst 25 (18%) were deemed to monitor disease progression. The resulting CD and DSS have different purposes. The ATTRv CD supports the collection of high-quality data for clinical research, whereas the ATTRv DSS can be rapidly conducted in a clinical setting and aid patient management.</p