Development of a Weight-Band Dosing Approach for Vosoritide in Children with Achondroplasia Using a Population Pharmacokinetic Model.

BACKGROUND AND OBJECTIVE: Vosoritide is a recently approved therapy for achondroplasia, the most common form of disproportionate short stature, that has been shown to be well tolerated and effective in increasing linear growth. This study aimed to develop a population pharmacokinetic (PPK) model to characterize pharmacokinetics (PK) of vosoritide and establish a weight-band dosing regimen. METHODS: A PPK model was developed using data from five clinical trials in children with achondroplasia (aged 0.95-15 years) who received daily per-kg doses of vosoritide. The model was used to simulate expected exposures in children with a refined weight-band dosing regimen. Simulated exposure was compared with the observed exposure from the pivotal clinical trial to evaluate appropriateness of the weight-band dosing regimen. RESULTS: A one-compartment model with a change-point first-order absorption and first-order elimination accurately described PK of vosoritide in children with achondroplasia. Body weight was found to be a predictor of vosoritide's clearance and volume of distribution. Additionally, it was observed that dosing solution concentration and duration of treatment influenced bioavailability. The weight-band dosing regimen resulted in simulated exposures that were within the range demonstrated to be well tolerated and effective in the pivotal clinical trial and showed improved consistency in drug exposure across the achondroplasia population. CONCLUSIONS: The weight-band dosing regimen reduced the number of recommended dose levels by body weight and is expected to simplify dosing for children with achondroplasia and their caregivers. CLINICAL TRIAL REGISTRATION: NCT02055157, NCT02724228, NCT03197766, NCT03424018, and NCT03583697.

Vosoritide Therapy in Children with Achondroplasia: Early Experience and Practical Considerations for Clinical Practice.

INTRODUCTION: Vosoritide is the first precision medical therapy approved to increase growth velocity in children with achondroplasia. Sharing early prescribing experiences across different regions could provide a framework for developing practical guidance for the real-world use of vosoritide. METHODS: Two meetings were held to gather insight and early experience from experts in Europe, the Middle East, and the USA. The group comprised geneticists, pediatric endocrinologists, pediatricians, and orthopedic surgeons. Current practices and considerations for vosoritide were discussed, including administration practicalities, assessments, and how to manage expectations. RESULTS: A crucial step in the management of achondroplasia is to determine if adequate multidisciplinary support is in place. Training for families is essential, including practical information on administration of vosoritide, and how to recognize and manage injection-site reactions. Advocated techniques include establishing a routine, empowering patients by allowing them to choose injection sites, and managing pain. Patients may discontinue vosoritide if they cannot tolerate daily injections or are invited to participate in a clinical trial. Clinicians in Europe and the Middle East emphasized the importance of assessing adherence to daily injections, as non-adherence may impact response and reimbursement. Protocols for monitoring patients receiving vosoritide may be influenced by regional differences in reimbursement and healthcare systems. Core assessments may include pubertal staging, anthropometry, radiography to confirm open physes, the review of adverse events, and discussion of concomitant or new medications-but timing of these assessments may also differ regionally and vary across institutions. Patients and families should be informed that response to vosoritide can vary in both magnitude and timing. Keeping families informed regarding vosoritide clinical trial data is encouraged. CONCLUSION: The early real-world experience with vosoritide is generally positive. Sharing these insights is important to increase understanding of the practicalities of treatment with vosoritide in the clinical setting.

Novel therapies for growth disorders.

As we continue to understand more about the complex mechanism of growth, a plethora of novel therapies have recently been developed that aim to address barriers and optimize efficacy. This review aims to explore these novel therapies and provide a succinct review based on the latest clinical studies in order to introduce clinicians to therapies that will soon constitute the future in the field of short stature.  Conclusion: The review focuses on long-acting growth hormone formulations, a novel growth hormone oral secretagogue, novel treatments for children with achondroplasia, and targeted therapies for rare forms of skeletal dysplasias. What is Known: • Recombinant human growth hormone has been the mainstay of treatment for children with short stature for years. • Such therapy is not always effective based on the underlying diagnosis (e.g achondroplasia, Turner syndrome). Compliance with daily injections is challenging and can directly affect efficacy. What is New: • Recent development of long-acting growth hormone regimens and oral secretagogues can overcome some of these barriers, however several limitations need to be taken into consideration. • Newer therapies for achondroplasia, and other rare forms of skeletal dysplasias introduce us to a new era of targeted therapies for children with short stature. Clinicians ought to be aware of pitfalls and caveats before introducing these novel therapies to every day practice.

Vosoritide therapy in children with achondroplasia aged 3-59 months: a multinational, randomised, double-blind, placebo-controlled, phase 2 trial.

BACKGROUND: Vosoritide is a recombinant C-type natriuretic peptide analogue that increases annualised growth velocity in children with achondroplasia aged 5-18 years. We aimed to assess the safety and efficacy of vosoritide in infants and children younger than 5 years. METHODS: This double-blind, randomised, placebo-controlled, phase 2 trial was done in 16 hospitals across Australia, Japan, the UK, and the USA. Children younger than 60 months with a clinical diagnosis of achondroplasia confirmed by genetic testing and who had completed a baseline growth study or observation period were enrolled into one of three sequential cohorts based on age at screening: 24-59 months (cohort 1); 6-23 months (cohort 2); and 0-5 months (cohort 3). Each cohort included sentinels who received vosoritide to determine appropriate daily drug dose, with the remainder randomly assigned (1:1) within each age stratum (except in Japan, where participants were randomly assigned within each cohort) to receive daily subcutaneous injections of vosoritide (30·0 µg/kg for infants aged 0-23 months; 15·0 µg/kg for children aged 24-59 months) or placebo for 52 weeks. Participants, caregivers, investigators, and the sponsor were masked to treatment assignment. The first primary outcome was safety and tolerability, assessed in all participants who received at least one study dose. The second primary outcome was change in height Z score at 52 weeks from baseline, analysed in all randomly assigned participants. This trial is registered with EudraCT, 2016-003826-18, and ClinicalTrials.gov, NCT03583697. FINDINGS: Between May 13, 2018, and March 1, 2021, 75 participants were recruited (37 [49%] females). 11 were assigned as sentinels, whereas 32 were randomly assigned to receive vosoritide and 32 placebo. Two participants discontinued treatment and the study: one in the vosoritide group (death) and one in the placebo group (withdrawal). Adverse events occurred in all 75 (100%) participants (annual rate 204·5 adverse events per patient in the vosoritide group and 73·6 per patient in the placebo group), most of which were transient injection-site reactions and injection-site erythema. Serious adverse events occurred in three (7%) participants in the vosoritide group (decreased oxygen saturation, respiratory syncytial virus bronchiolitis and sudden infant death syndrome, and pneumonia) and six (19%) participants in the placebo group (petit mal epilepsy, autism, gastroenteritis, vomiting and parainfluenza virus infection, respiratory distress, and skull fracture and otitis media). The least-squares mean difference for change from baseline in height Z score between the vosoritide and placebo groups was 0·25 (95% CI -0·02 to 0·53). INTERPRETATION: Children with achondroplasia aged 3-59 months receiving vosoritide for 52 weeks had a mild adverse event profile and gain in the change in height Z score from baseline. FUNDING: BioMarin Pharmaceutical.

Cell-based screen identifies porphyrins as FGFR3 activity inhibitors with therapeutic potential for achondroplasia and cancer.

Overactive fibroblast growth factor receptor 3 (FGFR3) signaling drives pathogenesis in a variety of cancers and a spectrum of short-limbed bone dysplasias, including the most common form of human dwarfism, achondroplasia (ACH). Targeting FGFR3 activity holds great promise as a therapeutic approach for treatment of these diseases. Here, we established a receptor/adaptor translocation assay system that can specifically monitor FGFR3 activation, and we applied it to identify FGFR3 modulators from complex natural mixtures. An FGFR3-suppressing plant extract of Amaranthus viridis was identified from the screen, and 2 bioactive porphyrins, pheophorbide a (Pa) and pyropheophorbide a, were sequentially isolated from the extract and functionally characterized. Further analysis showed that Pa reduced excessive FGFR3 signaling by decreasing its half-life in FGFR3-overactivated multiple myeloma cells and chondrocytes. In an ex vivo culture system, Pa alleviated defective long bone growth in humanized ACH mice (FGFR3ACH mice). Overall, our study presents an approach to discovery and validation of plant extracts or drug candidates that target FGFR3 activation. The compounds identified by this approach may have applications as therapeutics for FGFR3-associated cancers and skeletal dysplasias.

Burden and Treatment of Achondroplasia: A Systematic Literature Review.

BACKGROUND: Achondroplasia is the most common form of skeletal dysplasia. Recent advances in therapeutic options have highlighted the need for understanding the burden and treatment landscape of the condition. This systematic literature review (SLR) aimed to identify health-related quality of life (HRQoL)/utilities, healthcare resource use (HCRU), costs, efficacy, safety and economic evaluation data in achondroplasia and to identify gaps in the research. METHODS: Searches of MEDLINE, Embase, the University of York Centre for Reviews and Dissemination (CRD), the Cochrane Library and grey literature were performed. Articles were screened against pre-specified eligibility criteria by two individuals and study quality was assessed using published checklists. Additional targeted searches were conducted to identify management guidelines. RESULTS: Fifty-nine unique studies were included. Results demonstrated a substantial HRQoL and HCRU/cost-related burden of achondroplasia on affected individuals and their families throughout their lifetimes, particularly in emotional wellbeing and hospitalisation costs and resource use. Vosoritide, growth hormone (GH) and limb lengthening all conferred benefits for height or growth velocity; however, the long-term effects of GH therapy were unclear, data for vosoritide were from a limited number of studies, and limb lengthening was associated with complications. Included management guidelines varied widely in their scope, with the first global effort to standardise achondroplasia management represented by the International Achondroplasia Consensus Statement published at the end of 2021. Current evidence gaps include a lack of utility and cost-effectiveness data for achondroplasia and its treatments. CONCLUSIONS: This SLR provides a comprehensive overview of the current burden and treatment landscape for achondroplasia, along with areas where evidence is lacking. This review should be updated as new evidence becomes available on emerging therapies.

Current and emerging therapies for Achondroplasia: The dawn of precision medicine.

Achondroplasia is a rare disease affecting bone growth and is caused by a missense mutation in the fibroblast growth factor receptor 3 (FGFR3) gene. In the past few years, there were multiple experimental drugs entering into clinical trials for treating achondroplasia including vosoritide, the first precision medicine approved for this indication. This perspective presents the mechanism of action, benefit, and potential mechanistic limitation of the drugs currently being evaluated in clinical trials for achondroplasia. This article also discusses the potential impact of those drugs not only in increasing the growth of individuals living with achondroplasia but also in improving their quality of life.

Parents' Experience of Administering Vosoritide: A Daily Injectable for Children with Achondroplasia.

INTRODUCTION: Vosoritide is the first approved pharmacological treatment for achondroplasia and is indicated for at-home injectable administration by a trained caregiver. This research aimed to explore parents' and children's experience of initiating vosoritide and administering this treatment at home. METHODS: Qualitative telephone interviews were conducted with parents of children being treated with vosoritide in France and Germany. Interviews were transcribed and analysed using thematic analysis. RESULTS: Fifteen parents participated in telephone interviews in September and October 2022. The median age of children in this sample was 8 years old (range 3-13 years) and children had been taking treatment from 6 weeks to 13 months. Four themes document families' experience with vosoritide: (1) awareness of vosoritide treatment, uncovering that parents first heard of vosoritide through their own research, patient advocacy groups, or through their physicians; (2) treatment understanding and decision-making, which found that their decision to take treatment is based on a desire to relieve future medical complications and increase height for improved independence, and they consider the extent to which the treatment has severe side effects; (3) training and initiation, which showed that the hospital initiation and training sessions varied considerably both across and within countries, with different treatment centres taking different approaches; and (4) managing treatment at home brings psychological and practical challenges, which are ultimately overcome with perseverance and available support. CONCLUSIONS: Parents and children are resilient to challenges posed by a daily injectable treatment and highly motivated to improve their quality of life. Parents are prepared to overcome short-term treatment challenges for future gains in terms of health and functional independence for their children. Greater support could ensure they have the right information to initiate treatment and manage treatment at home, which will improve parents' and children's experience.

CurQ+, a Next-Generation Formulation of Curcumin, Ameliorates Growth Plate Chondrocyte Stress and Increases Limb Growth in a Mouse Model of Pseudoachondroplasia.

Mutations in cartilage oligomeric matrix protein (COMP) causes protein misfolding and accumulation in chondrocytes that compromises skeletal growth and joint health in pseudoachondroplasia (PSACH), a severe dwarfing condition. Using the MT-COMP mice, a murine model of PSACH, we showed that pathological autophagy blockage was key to the intracellular accumulation of mutant-COMP. Autophagy is blocked by elevated mTORC1 signaling, preventing ER clearance and ensuring chondrocyte death. We demonstrated that resveratrol reduces the growth plate pathology by relieving the autophagy blockage allowing the ER clearance of mutant-COMP, which partially rescues limb length. To expand potential PSACH treatment options, CurQ+, a uniquely absorbable formulation of curcumin, was tested in MT-COMP mice at doses of 82.3 (1X) and 164.6 mg/kg (2X). CurQ+ treatment of MT-COMP mice from 1 to 4 weeks postnatally decreased mutant COMP intracellular retention, inflammation, restoring both autophagy and chondrocyte proliferation. CurQ+ reduction of cellular stress in growth plate chondrocytes dramatically reduced chondrocyte death, normalized femur length at 2X 164.6 mg/kg and recovered 60% of lost limb growth at 1X 82.3 mg/kg. These results indicate that CurQ+ is a potential therapy for COMPopathy-associated lost limb growth, joint degeneration, and other conditions involving persistent inflammation, oxidative stress, and a block of autophagy.

Juvenile toxicity study of PF-07256472/recifercept, a recombinant human soluble fibroblast growth factor receptor 3, in 2-3-month-old cynomolgus monkeys.

Achondroplasia is an autosomal disorder caused by point mutation in the gene encoding fibroblast growth factor receptor 3 (FGFR3) and resulting in gain of function. Recifercept is a potential disease modifying treatment for achondroplasia and functions as a decoy protein that competes for ligands of the mutated FGFR3. Recifercept is intended to restore normal bone growth by preventing the mutated FGFR3 from negative inhibitory signaling in pediatric patients with achondroplasia. Here we evaluated the potential effects of twice weekly administration of recifercept to juvenile cynomolgus monkeys (approximately 3-months of age at the initiation of dosing) for 6-months. No adverse effects were noted in this study, identifying the high dose as the no-observed-adverse-effect-level and supporting the use of recifercept in pediatric patients from birth. Considering that juvenile toxicity studies in nonhuman primates are not frequently conducted, and when they are conducted they typically utilize animals ≥9 months of age, this study demonstrates the feasibility of executing a juvenile toxicity study in very young monkeys prior to weaning.

Clinical Manifestations and Outcomes of 20 Korean Hypochondroplasia Patients with the FGFR3 N540K variant.

BACKGROUND: Hypochondroplasia is a skeletal dysplasia caused by activating pathologic variants of FGFR3. The N540K variant accounts for 60-70% of reported cases and is associated with severe manifestations. Here, we analyze the clinical manifestations and outcomes of Korean patients with hypochondroplasia harboring the FGFR3 N540K variant. METHODS: Medical records of 20 unrelated patients with genetically confirmed N540K-related hypochondroplasia were retrospectively reviewed. All individuals were diagnosed with hypochondroplasia by Sanger sequencing for FGFR3, or target-panel sequencing for skeletal dysplasia. The effectiveness of growth hormone therapy was analyzed in 16 patients treated with growth hormones. RESULTS: Among 20 patients (7 men, 13 women), the mean age at first visit was 3.5±1.0 years, and the mean follow-up duration was 6.8±0.6 years. The patients presented with a short stature and/or short limbs. Genu varum, macrocephaly, and developmental delay were observed in 11 (55.0%), 9 (45.0%), and 5 (25.0%) patients, respectively. Of the 12 patients who underwent neuroimaging, five (41.7%) showed abnormal findings (one required operation for obstructive hydrocephalus). Among 16 growth-hormone-treated patients (two were growth-hormone deficient), the increase in height standard deviation scores was significant after a mean 5.4±0.7 years of treatment (+0.6 and+1.8 using growth references for healthy controls and achondroplasia children, respectively). Four patients underwent surgical limb lengthening at a mean age of 8.8±3.3 years. CONCLUSIONS: Neurodevelopmental abnormalities are frequently observed in patients with N540K-related hypochondroplasia. Close monitoring of skeletal manifestations and neurodevelopmental status is necessary for hypochondroplasia.

Novel Treatment Options in Childhood Bone Diseases.

BACKGROUND: Several novel treatment options have recently become available in childhood bone diseases. The purpose of this article is to provide an update on some of the therapeutic agents used in the treatment of pediatric osteoporosis, X-linked hypophosphatemic rickets, and achondroplasia (ACH). SUMMARY: Vitamin D3 and Ca supplementation remains the basis of childhood osteoporosis treatment. Bisphosphonate (BP) therapy is the main antiresorptive therapeutic option, while denosumab, a human monoclonal IgG2 antibody with high affinity and specificity for a primary regulator of bone resorption - RANKL, represents a possible alternative. Its potent inhibition of bone resorption and turnover process leads to continuous increase of bone mineral density throughout the treatment also in the pediatric population. With a half-life much shorter than BPs, its effects are rapidly reversible upon discontinuation. Safety and dosing concerns in children remain. Novel treatment options have recently become available in two rare bone diseases. Burosumab, a monoclonal antibody against FGF-23, has been approved for the treatment of children with X-linked hypophosphatemic rickets older than 1 year. It presents an effective, more etiology-based treatment for rickets compared to conventional therapy, without the need for multiple daily oral phosphate supplementation. Its long-term efficacy and safety are currently being investigated. After years of anticipation, a novel treatment option for ACH has become available. C-type natriuretic peptide analog vosoritide effectively increases proportional growth and has a reasonable safety profile in children >2 years. Its effect on other features of the disease and the final height is yet to be determined. Several other treatment options for ACH exploring different therapeutic approaches are currently being investigated. KEY MESSAGES: Denosumab is effective in the treatment of childhood-onset osteoporosis; however, further studies are necessary to determine the optimal treatment protocol. Burosumab is more etiology-based and convenient in comparison to conventional treatment of X-linked hypophospha--temic rickets in children and adults. Vosoritide importantly changes the natural course of achondroplasia, at least in the short term.

Alerta monitoramento do horizonte tecnológico: Vosoritida para o tratamento de Acondroplasia / Technological horizon monitoring alert: Vosoritida for the treatment of Achondroplasia

A TECNOLOGIA: Descrição da tecnologia: A vosoritida é uma molécula análoga ao peptídeo natriurético do tipo C (CNP ­ do inglês: C-type natriuretic peptide), um hormônio natural que regula o crescimento linear dos ossos. Esse medicamento inibe a via da proteína quinase, que ativa a jusante do receptor do fator de crescimento de fibroblastos 3 (FGFR3). Como resultado, a vosoritida atua como um regulador positivo da ossificação endocondral, uma vez que promove a proliferação e diferenciação dos condrócitos. Condição clínica: A acondroplasia é uma doença genética rara descrita como a displasia esquelética primária mais comum em humanos. Essa forma de displasia é responsável por mais de 90% dos casos de baixa estatura desproporcional, também conhecida como nanismo. Etimologicamente, o termo acondroplasia significa "sem formação de cartilagem" e é categorizada como uma displasia fisária (da placa de crescimento). A acondroplasia ocorre em aproximadamente 1:20.000 a 1:30.000 nascidos vivos por ano. Por difícil que seja determinar a prevalência global dessa condição, estima-se que ela afete aproximadamente 1 a 9 indivíduos por 100.000 da população geral. Um extenso estudo epidemiológico de base populacional europeu calculou a prevalência em 3,72 por 100.000 nascimentos (8). Esse estudo demonstrou que a prevalência foi estável ao longo do tempo, contudo, foram observadas diferenças regionais. INFORMAÇÕES REGULATÓRIAS: Informações sobre registro: A vosoritida foi registrada em 29/11/2021 na Agência Nacional de Vigilância Sanitária (Anvisa) como um produto novo, cumprindo com o disposto na RDC nº 55/2010 para o registro de produtos biológicos novos. Por se tratar de uma necessidade médica não atendida atualmente, este produto foi priorizado de acordo com os critérios da RDC nº 204/2017 e nas agências reguladoras internacionais para as seguintes indicações clínicas: Agência Nacional de Vigilância Sanitária (Anvisa): indicado para o tratamento de acondroplasia (ACH) em pacientes a partir de 2 anos de idade e cujas epífises não estão fechadas. O diagnóstico de acondroplasia deve ser confirmado por teste genético apropriado. U.S. Food and Drug Administration (FDA): é indicado para aumentar o crescimento linear em pacientes pediátricos com acondroplasia com 5 anos de idade ou mais com epífises abertas. Essa é uma autorização contingente, o que significa que para ser mantida, os benefícios clínicos deverão ser confirmados por ensaio clínico. European Medicines Agency (EMA): é indicado para o tratamento da acondroplasia em crianças a partir dos dois anos de idade até o fechamento das placas de crescimento. Pharmaceuticals and Medical Devices Agency (PMDA): é indicado para o tratamento de crianças de todas as idades que ainda não tiveram o fechamento das placas de crescimento. PANORAMA DE DESENVOLVIMENTO: Estratégia de busca: A estratégia de busca foi composta por duas etapas. A primeira objetivou identificar os registros de estudos clínicos do vosoritida para o tratamento de acondroplasia no ClinicalTrials.gov e no Cortellis. A busca no Cortellis foi realizada em 17 de agosto de 2022 com o termo 'vosoritide'. Já a busca no ClinicalTrials foi realizada em 19 de agosto de 2022 com os termos 'vosoritide' e 'achondroplasia'. Foram incluídos ensaios clínicos, randomizados ou não, a partir da fase 2, em que o vosoritida tenha sido utilizado para o tratamento da acondroplasia. Não houve restrição quanto ao idioma. Não foram incluídas análises post hocs, pool analysis. Na segunda etapa, foi realizada busca nas bases Medline e PMC (via PubMed) e Embase (via Portal Periódicos Capes) com o objetivo de localizar estudos publicados e não publicados referentes aos ensaios clínicos conduzidos que utilizaram o vosoritida no tratamento da acondroplasia. Desta forma, foram construídas estratégias de busca utilizando termos controlados e seus respectivos sinônimos (Apêndice 1). Estas buscas foram realizadas em 5 de setembro de 2022. CONSIDERAÇÕES FINAIS: A acondroplasia é causada por mutações no gene do receptor 3 do fator de crescimento de fibroblastos, que levam à ossificação endocondral prejudicada. O medicamento vosoritida é um análogo do peptídeo natriurético tipo C, que foi desenvolvido para o tratamento de crianças portadoras dessa doença. Os resultados disponíveis, até a última atualização deste alerta, foram promissores e subsidiaram o registro da vosoritida em vários países, inclusive no Brasil. Mas é importante destacar que devido à variabilidade do crescimento e ao menor pico de crescimento durante a puberdade, em crianças com acondroplaisa, os efeitos a longo prazo da vosoritida só serão conhecidos quando as crianças atingirem a altura adulta final.

Vosoritide para acondroplasia con epífisis abierta / Vosoritide for achondroplasia with epiphysis open

INTRODUCCIÓN: La acondroplasia es la causa más común de baja estatura desproporcionada. Es causada por una mutación patogénica en el gen del receptor 3 del factor de crecimiento de fibroblastos (FGFR3, siglas del inglés Fibroblast Growth Factor Receptor 3), que codifica un receptor transmembrana importante en la regulación del crecimiento lineal de los huesos largos. Esto resulta en una alteración de la osificación endocondral, provocando un crecimiento desproporcionado, donde el crecimiento del tronco no se ve tan gravemente afectado como el de las extremidades y el cráneo. En el 80% de los casos es producida por una mutación genética de novo, siendo de herencia autosómica dominante. Cuando ambos padres tienen acondroplasia, la probabilidad de que cada uno de sus futuros hijos pueda tener una estatura promedio es del 25%, tener acondroplasia es del 50% y finalmente tener acondroplasia homocigota (que suele ser letal) es del 25%. La acondroplasia afecta el crecimiento de casi todos los huesos del cuerpo, incluidos el cráneo, la columna vertebral, los brazos y las piernas, lo que da como resultado una estatura muy baja con una apariencia característica: acortamiento predominantemente proximal (humero, fémur) de los huesos largos de las extremidades (rizomelia); de los dedos de las manos secundario a huesos metacarpianos cortos (braquidactilia), cifosis (deformidad convexa de la unión torácica-lumbar), compresión cervicomedular (debido al estrechamiento en la parte superior de la columna secundario al estrechamiento del foramen magnum); macrocefalia y rasgos faciales caracterizado por prominencia frontal y retrusión del tercio medio facial. Las personas afectadas pueden sufrir alguna de las complicaciones adicionales: hidrocefalia; estenosis del canal vertebral (pacientes después de su segunda o tercera década de vida); obstrucción de la vía aérea superior/apnea obstructiva del sueño (secundario a la reducción del espacio de las vías respiratorias por la retrusión de la parte media de la cara junto con el agrandamiento de adenoides y amígdalas); deformidades óseas (genu varum: desviación hacia afuera debido al arqueamiento); malformación de Arnold-Chiari; microftalmos, y disfunción del oído medio, obesidad, hipertensión arterial, problemas de movilidad, dolor crónico y baja actividad física. OBJETIVO: El objetivo del presente informe es evaluar la evidencia disponible acerca de la eficacia, seguridad, aspectos económicos, recomendaciones de sociedades científicas y las políticas de cobertura (PC) para el uso del vosoritide para personas con acondroplasia y epífisis abierta. DESCRIPCIÓN DE LA TECNOLOGÍA: El vosoritide (BMN 111) es un péptido natriurético humano tipo C recombinante modificado que es producido en células de Escherichia coli mediante tecnología de ADN recombinante. En los pacientes con acondroplasia, el gen FGFR3 que regula el crecimiento está "activado" permanentemente, impidiendo el crecimiento normal de los huesos por lo que terminan siendo más cortos de lo habitual.33 Vosoritide actúa uniéndose a un receptor denominado receptor del péptido natriurético tipo B, que reduce la actividad de FGFR3, y esto, promueve la proliferación y diferenciación de condrocitos y el crecimiento óseo endocondral. MÉTODOS: Las búsquedas se llevaron a cabo en las principales bases de datos bibliográficas: PUBMED, CRD (Centre for Reviews and Dissemination), Cochrane, TRIPdatabase (TRIP: Turning Research Into Practice), Epistemonikos, BRISA (Base Regional de Informes de Evaluación de Tecnologías en Salud de las Américas), LILACS (Literatura Latinoamericana y del Caribe en Ciencias de la Salud), INAHTA (International Network of Agencies for Health Technology Assessment), PROSPERO (International Prospective Register Of Systematic Reviews), en buscadores genéricos de internet y en sitios web de financiadores de salud. Se realizó una búsqueda sistemática de información publicada con fecha límite hasta el 29 de junio sobre el uso del vosoritide en pacientes con Acondroplasia y epífisis abierta. Se priorizó para la búsqueda inicial, la identificación de Revisiones Sistemáticas (RS) y Metaanálisis (MA), Evaluaciones de Tecnologías Sanitarias (ETS), Evaluaciones Económicas (EE), Guías de Práctica Clínica (GPC), políticas de cobertura (PC) de diferentes sistemas de salud y ensayos clínicos aleatorizados (ECA), se realizó una búsqueda con los filtros metodológicos correspondientes. RESULTADOS: Como resultado de la búsqueda bibliográfica, se recuperaron 12 estudios: ocho en curso, cuatro finalizados (estudio 111-101 [NCT01590446], estudio 111-202 [NCT02055157], Savarirayan y cols. 2020 [111-301, NCT03197766] y Savarirayan y cols. 2021 [111-302, NCT03424018]; tres Evaluaciones de Tecnologías Sanitarias (ETS); una revisión sistemática en curso; cinco Guías de Práctica Clínica (GPC) / Consensos / Recomendaciones. No se han hallado estudios primarios con comparación "cabeza-cabeza" entre el vosoritide versus cirugía de alargamiento u hormona de crecimiento. CONCLUSIONES: Al momento, no está autorizada su comercialización en Argentina, pero está en evaluación por el Registro de Especialidades Médicas. No se han encontrado estudios primarios con comparación "cabeza-cabeza" entre el vosoritide versus cirugía de alargamiento u hormona de crecimiento. No se recuperó evidencia relacionado con la tasa de complicaciones graves como: estrechez de la unión cérvico-medular; macrocefalia/hidrocefalia; estenosis del canal vertebral; obstrucción de la vía aérea superior; deformidades óseas; malformación de Arnold-Chiari; microftalmos. No hubo diferencias clínicamente significativas en la calidad de vida relacionada con la salud, ni tampoco en la independencia funcional para vosoritide frente a placebo en personas de 5 a 18 años de edad con acondroplasia y epífisis abierta (certeza alta ⨁⨁⨁⨁). Aumenta la velocidad de crecimiento anualizada (1,57 cm/año más alto), aunque se desconoce si se sostiene en el tiempo para vosoritide frente a placebo en personas de 5 a 18 años de edad con acondroplasia y epífisis abierta (certeza alta ⨁⨁⨁⨁). Aumenta la puntuación Z a 52 semanas de seguimiento (cambio medio de mínimos cuadrados 0.28 más alto), aunque se desconoce si se sostiene en el tiempo, para vosoritide frente a placebo en personas de 5 a 18 años de edad con acondroplasia y epífisis abierta (certeza alta ⨁⨁⨁⨁). No hay diferencias en la proporción de segmentos corporales superiores e inferiores entre el inicio y el final de seguimiento, para vosoritide frente a placebo en personas de 5 a 18 años de edad con acondroplasia y epífisis abierta (certeza alta ⨁⨁⨁⨁). Si bien probablemente no aumente el riesgo de eventos adversos serios, y aumenta el riesgo de cualquier evento adverso (certeza alta ⨁⨁⨁⨁). No se recuperaron Guías de Práctica Clínica que recomienden su utilización y la mayoría de las políticas de cobertura relevadas no la mencionan en la indicación evaluada. Si bien no existen evaluaciones económicas locales, se estima que podría ser NO costoefectiva en Argentina. Se estimó que el impacto en términos de costo de oportunidad requeriría sumar 32.870 gastos en salud per cápita por año, o limitaría el pago de 1.232 haberes jubilatorios mínimos anuales.

Efficacy of vosoritide in the treatment of achondroplasia.

Achondroplasia is the commonest form of dwarfism and results from a mutation in the fibroblast growth factor receptor 3 (FGFR3) gene on chromosome 4p16.3. The mutation is at nucleotide 1138 resulting in a G-to-A transition (134934.0001). This condition is characterized by full penetration meaning that everyone with this genetic mutation will exhibit the phenotypic characteristics of achondroplasia. It is a gain-of function mutation that causes increased inhibition of cartilage formation. C-type natriuretic peptide (CNP) acts on the growth plate through the natriuretic peptide receptor-B (NPR-B) causing the transformation of guanosine 5'-triphosphate into cyclic guanosine monophosphate. However, CNP cannot be used in the treatment of achondroplasia because it is rapidly degraded by neutral endopeptidase. Vosoritide is a modified recombinant human CNP and has a half-life 10 times that of CNP. Clinical trials have demonstrated that vosoritide is effective in significantly increasing the annualized growth velocity in children with achondroplasia before the fusion of the epiphyses.

A long-acting C-natriuretic peptide for achondroplasia.

The C-natriuretic peptide (CNP) analog vosoritide has recently been approved for treatment of achondroplasia in children. However, the regimen requires daily subcutaneous injections in pediatric patients over multiple years. The present work sought to develop a long-acting CNP that would provide efficacy equal to or greater than that of vosoritide but require less frequent injections. We used a technology for half-life extension, whereby a drug is attached to tetra-polyethylene glycol hydrogels (tetra-PEG) by ß-eliminative linkers that cleave at predetermined rates. These hydrogels-fabricated as uniform ∼60-µm microspheres-are injected subcutaneously, where they serve as a stationary depot to slowly release the drug into the systemic circulation. We prepared a highly active, stable CNP analog-[Gln6,14]CNP-38-composed of the 38 C-terminal amino acids of human CNP-53 containing Asn to Gln substitutions to preclude degradative deamidation. Two microsphere [Gln6,14]CNP-38 conjugates were prepared, with release rates designed to allow once-weekly and once-monthly administration. After subcutaneous injection of the conjugates in mice, [Gln6,14]CNP-38 was slowly released into the systemic circulation and showed biphasic elimination pharmacokinetics with terminal half-lives of ∼200 and ∼600 h. Both preparations increased growth of mice comparable to or exceeding that produced by daily vosoritide. Simulations of the pharmacokinetics in humans indicated that plasma [Gln6,14]CNP-38 levels should be maintained within a therapeutic window over weekly, biweekly, and likely, monthly dosing intervals. Compared with vosoritide, which requires ∼30 injections per month, microsphere [Gln6,14]CNP-38 conjugates-especially the biweekly and monthly dosing-could provide an alternative that would be well accepted by physicians, patients, and patient caregivers.

Literature review and expert opinion on the impact of achondroplasia on medical complications and health-related quality of life and expectations for long-term impact of vosoritide: a modified Delphi study.

BACKGROUND: Achondroplasia is associated with disproportionate short stature and significant and potentially severe medical complications. Vosoritide is the first medicine to treat the underlying cause of achondroplasia and data from phase 3 and phase 2 extension studies showed effects on growth and body proportions. However, there are currently no long-term data available on the direct impact on endpoints such as medical complications and health-related quality of life (HRQoL). This study explored the perceived impact of achondroplasia on medical complications, HRQoL, healthcare resource use and mortality, and potential modifying effects of vosoritide, based on published evidence and expert opinion. Structured expert opinion was obtained by an international modified Delphi study among 14 experts in managing achondroplasia performed on a virtual platform and consisting of an explorative phase followed by an anonymous individual rating round. RESULTS: Overall, the panelists expect that in individuals starting long-term treatment between 2 years of age and puberty, growth velocity increases observed in the clinical trials will be maintained until final height is reached (92% agreement) and will likely result in clinically meaningful improvements in upper-to-lower body segment ratio (85%). Earlier treatment initiation will likely result in a greater final height (100%) and more likely improve proportionality (92%) than later treatment. Although current data are limited, ≥ 75% of panelists find it conceivable that the earlier long-term treatment is started, the greater the probability of a positive effect on the lifetime incidence of symptomatic spinal stenosis, kyphosis, obstructive sleep apnea, and foramen magnum stenosis. These are among the most clinically important complications of achondroplasia because of their high impact on comorbidity, mortality, and/or HRQoL. A positive effect of vosoritide on the incidence of surgeries through lifetime was considered more likely with earlier long-term treatment (90%). CONCLUSIONS: This explorative study, based on international expert opinion, provides further insight into the medical and functional impacts of achondroplasia and how these might be modified through long-term use of vosoritide. The results can be used to guide the direction and design of future research to validate the assumptions and to discuss potential treatment outcomes with disease modifying therapies with families and clinicians.

Treatment Goals for Achondroplasia: A Qualitative Study with Parents and Adults.

INTRODUCTION: Achondroplasia is characterized by disproportionate short stature accompanied by other changes to the musculoskeletal system. Individuals with this condition typically experience a variety of medical complications. As pharmacologic treatments continue to be developed for the treatment of achondroplasia, it is important to understand treatment goals among those affected by achondroplasia and the factors that shape their goals. METHODS: This qualitative study is based on semi-structured interviews with 19 parents of children with achondroplasia and five adults with achondroplasia in the USA. We employed thematic analysis using an iterative process to identify themes across the interviews. RESULTS: Participants had two goals for pharmacologic treatment of achondroplasia: ameliorating complications associated with the condition and increasing stature to overcome functional limitations and psychosocial challenges. Complications of particular concern were chronic pain and surgeries to repair spinal, ear, nose, and throat (ENT) problems, and neurological sequelae. Increased height would enhance independence, help individuals to fit in socially, and avoid social stigma. Countervailing factors included the importance of stature to their identity and the concern that the condition would remain despite treatment. CONCLUSIONS: This study offers evidence about how individuals affected by achondroplasia think about the pharmacologic treatment of this condition, including both the benefits of ameliorating complications and increasing height. The findings can offer practical insights for parents of children considering treatment, treating physicians, and decision-makers evaluating coverage decisions for treatment of achondroplasia.

New Drug Treats Pediatric Achondroplasia.

The Food and Drug Administration has granted accelerated approval to vosoritide (Voxzogo) to treat children ages five years and older with achondroplasia who still have open epiphyses.Children prescribed vosoritide should have a meal and 240 to 300 mL of fluid in the hour prior to drug administration to prevent hypotensive episodes.