Early initiation of treatment with oral propranolol for infantile hemangioma improves success rate.

BACKGROUND/OBJECTIVES: Early referral and treatment of infantile hemangioma (IH) is a major challenge for treatment success. However, there is a lack of data supporting a specific threshold for initiating treatment with oral propranolol. The aim of this analysis was to find factors, such as age at treatment initiation, leading to a higher success rate with oral propranolol treatment. METHODS: Based on data from the pivotal phase 2-3 clinical trial of oral propranolol in IH, we used Generalized Additive Model (GAM) charts with Generalized Linear Models (GLM), then a rule discovery algorithm, to identify sub-groups presenting a high probability of occurrence of the predefined outcome (i.e., success [complete or nearly complete resolution of the target hemangioma] at 6 months of treatment). RESULTS: Our analyses identified that patients who started oral propranolol 3 mg/kg/day before the age of 10 weeks had a success rate of 86%, higher than the 60% success rate for all patients that received the same regimen commencing after 10 weeks of age. CONCLUSIONS: Treatment initiation before 10 weeks of age was associated with a significantly higher rate of treatment success with oral propranolol 3 mg/kg/day. Infants with IH requiring treatment should be referred to an expert center and treated as soon as possible.

Medical management of vascular anomalies of the head and neck.

Depending on impairment, treatment of vascular anomalies is decided on a case-by-case basis in pluridisciplinary consultations. Interventional treatments, especially surgery and sclerotherapy, are usually partially efficient and management of patients with vascular anomalies increasingly involves the use of medical drugs. The most common vascular tumor is infantile hemangioma where first-line medical treatment, when necessary, is propranolol. Kasabach-Merritt phenomenon is now largely treated with sirolimus whereas first-line treatment of coagulation disorders associated with venous malformations is based on low-molecular-weight heparins or direct anticoagulants. Sirolimus is the standard treatment for painful inflammatory manifestations of low-flow vascular malformations such capillary, venous, and lymphatic malformations that can occur singly or in combination but PIK3CA inhibitors, originally developed in oncology, have shown promising results in patients with PIK3CA-related overgrowth spectrum. Currently, medical treatments are poorly developed for high-flow malformations such as arteriovenous malformations. However, new research aimed at delineating the different arteriovenous malformations based on molecular findings has given new hope for future development of targeted therapies.

Is Infantile Hemangioma a Neuroendocrine Tumor?

Infantile hemangioma (IH) is the most common infantile tumor, affecting 5-10% of newborns. Propranolol, a nonselective ß-adrenergic receptor (ADRB) antagonist, is currently the first-line treatment for severe IH; however, both its mechanism of action and its main cellular target remain poorly understood. Since betablockers can antagonize the effect of natural ADRB agonists, we postulated that the catecholamine produced in situ in IH may have a role in the propranolol response. By quantifying catecholamines in the IH tissues, we found a higher amount of noradrenaline (NA) in untreated proliferative IHs than in involuted IHs or propranolol-treated IHs. We further found that the first three enzymes of the catecholamine biosynthesis pathway are expressed by IH cells and that their levels are reduced in propranolol-treated tumors. To study the role of NA in the pathophysiology of IH and its response to propranolol, we performed an in vitro angiogenesis assay in which IH-derived endothelial cells, pericytes and/or telocytes were incorporated. The results showed that the total tube formation is sensitive to propranolol only when exogenous NA is added in the three-cell model. We conclude that the IH's sensitivity to propranolol depends on crosstalk between the endothelial cells, pericytes and telocytes in the context of a high local amount of local NA.

Sirolimus (Rapamycin) for Slow-Flow Malformations in Children: The Observational-Phase Randomized Clinical PERFORMUS Trial.

IMPORTANCE: Sirolimus is increasingly being used to treat various vascular anomalies, although evidence of its efficacy is lacking. OBJECTIVE: To assess the efficacy and safety of sirolimus for children with slow-flow vascular malformations to better delineate the indications for treatment. DESIGN, SETTING AND PARTICIPANTS: This multicenter, open-label, observational-phase randomized clinical trial included 59 children aged 6 to 18 years with a slow-flow vascular malformation who were recruited between September 28, 2015, and March 22, 2018, in 11 French tertiary hospital centers. Statistical analysis was performed on an intent-to-treat basis from December 4, 2019, to November 10, 2020. INTERVENTIONS: Patients underwent an observational period, then switched to an interventional period when they received oral sirolimus (target serum levels, 4-12 ng/mL). The switch time was randomized from month 4 to month 8, and the whole study period lasted 12 months for each patient. MAIN OUTCOMES AND MEASURES: The primary outcome was change in the volume of vascular malformations detected on magnetic resonance imaging scan (with centralized interpretation) per unit of time (ie, between the interventional period and the observational period). Secondary outcomes included subjective end points: pain, bleeding, oozing, quality of life, and safety. RESULTS: Among the participants (35 girls [59.3%]; mean [SD] age, 11.6 [3.8] years), 22 (37.3%) had a pure venous malformation, 18 (30.5%) had a cystic lymphatic malformation, and 19 (32.2%) had a combined malformation, including syndromic forms. Variations in the volume of vascular malformations detected on magnetic resonance imaging scans associated with the duration period were not overall significantly different between the interventional period and the observational period (all vascular malformations: mean [SD] difference, -0.001 [0.007]; venous malformations: mean [SD] difference, 0.001 [0.004]; combined malformations: mean [SD] difference, 0.001 [0.009]). However, a significant decrease in volume was observed for children with pure lymphatic malformations (mean [SD] difference, -0.005 [0.005]). Overall, sirolimus had positive effects on pain, especially for combined malformations, and on bleeding, oozing, self-assessed efficacy, and quality of life. During sirolimus treatment, 56 patients experienced 231 adverse events (5 serious adverse events, none life-threatening). The most frequent adverse event was an oral ulcer (29 patients [49.2%]). CONCLUSIONS AND RELEVANCE: This observational-phase randomized clinical trial allows for clarifying the goals of patients and families when starting sirolimus therapy for children older than 6 years. Pure lymphatic malformations seem to be the best indication for sirolimus therapy because evidence of decreasing lymphatic malformation volume per unit of time, oozing, and bleeding and increasing quality of life was found. In combined malformations, sirolimus significantly reduced pain, oozing, and bleeding. Benefits seemed lower for pure venous malformations than for the 2 other subgroups, also based on symptoms. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02509468; clinicaltrialsregister.eu Identifier: 2015-001096-43.

Critical role of Aquaporin-1 and telocytes in infantile hemangioma response to propranolol beta blockade.

Propranolol, a nonselective ß-adrenergic receptor (ADRB) antagonist, is the first-line therapy for severe infantile hemangiomas (IH). Since the incidental discovery of propranolol efficacy in IH, preclinical and clinical investigations have shown evidence of adjuvant propranolol response in some malignant tumors. However, the mechanism for propranolol antitumor effect is still largely unknown, owing to the absence of a tumor model responsive to propranolol at nontoxic concentrations. Immunodeficient mice engrafted with different human tumor cell lines were treated with anti-VEGF bevacizumab to create a model sensitive to propranolol. Proteomics analysis was used to reveal propranolol-mediated protein alteration correlating with tumor growth inhibition, and Aquaporin-1 (AQP1), a water channel modulated in tumor cell migration and invasion, was identified. IH tissues and cells were then functionally investigated. Our functional protein association networks analysis and knockdown of ADRB2 and AQP1 indicated that propranolol treatment and AQP1 down-regulation trigger the same pathway, suggesting that AQP1 is a major driver of beta-blocker antitumor response. Examining AQP1 in human hemangioma samples, we found it exclusively in a perivascular layer, so far unrecognized in IH, made of telocytes (TCs). Functional in vitro studies showed that AQP1-positive TCs play a critical role in IH response to propranolol and that modulation of AQP1 in IH-TC by propranolol or shAQP1 decreases capillary-like tube formation in a Matrigel-based angiogenesis assay. We conclude that IH sensitivity to propranolol may rely, at least in part, on a cross talk between lesional vascular cells and stromal TCs.

Congenital haemangiomas: a single-centre retrospective review.

OBJECTIVE: Congenital haemangiomas (CHs) are rare, benign vascular tumours that are fully developed at birth. Three subtypes of CHs have been described based on clinical behaviour: rapidly involuting CHs (RICHs), non-involuting CHs (NICHs) and partially involuting CHs (PICHs). We explore in our study clinical, evolutionary and paraclinical characteristics of the three CH subtypes. DESIGN: Children with CH attending our department of paediatric dermatology at Bordeaux University Hospital over a 13-year period were retrospectively included. Epidemiological, clinical and evolutionary data, photographs and imaging results were reviewed. All available tissue samples were histologically examined. RESULTS: We included 57 patients: 22 with RICH, 22 with NICH and 13 with PICH. Males predominated (ratio 1.7); the most common CH location was on the limbs. RICH, NICH and PICH exhibited overlapping characteristics; all were single telangiectatic lesions with pale peripheral halos. At birth, NICHs were flat but RICHs and PICHs bulky. The median age at complete RICH involution was 12 months. One-third of CHs that appeared RICH-like at birth underwent incomplete involution to become PICHs. Heart failure and thrombocytopenia were rare complications. PICHs were frequently ulcerated. Pain was common for NICH and PICH. The imaging and histological data of the three CH subtypes were rather similar. CONCLUSIONS: We describe the characteristics and evolution of the three CH subtypes using a case series. Certain overlapping features were apparent, reinforcing the hypothesis that RICH, NICH and PICH lie on the same pathological spectrum.

Cutaneous Infantile Haemangiomas with Intracranial and Intraspinal Involvement: A European Multicentre Experience and Review.

Infantile haemangiomas are very common benign tumours in the first months of life. They are mostly cutaneous; however, extracutaneous lesions are possible, and occur in very rare cases in the central nervous system. A European multicentre observational retrospective study was conducted in the last 5 years. Seven patients with intracranial or intraspinal infantile haemangiomas were selected and treated with oral propranolol. Propranolol was interrupted after complete or almost complete resolution of infantile haemangiomas. All patients tolerated the treatment well without side-effects. Central nervous system infantile haemangiomas are probably underestimated due to the frequent absence of symptoms and their spontaneous involution. However, they should be investigated in case of segmental cutaneous infantile haemangiomas, particularly on the head, neck, upper trunk, lumbar or sacral area in order to diagnosis intra-central nervous system involvement at an early stage.

The Infantile Hemangioma Referral Score: A Validated Tool for Physicians.

OBJECTIVES: Infantile hemangiomas (IHs) are common; some cases require timely referral and treatment to prevent complications. We developed and validated a reliable instrument for timely and adequate referral of patients with IH to experts by nonexpert primary physicians. METHODS: In this multicenter, cross-sectional, observational study, we used a 3-stage process: (1) development of the Infantile Hemangioma Referral Score (IHReS) tool by IH experts who selected a representative set of 42 IH cases comprising images and a short clinical history, (2) definition of the gold standard for the 42 cases by a second independent committee of IH experts, and (3) IHReS validation by nonexpert primary physicians using the 42 gold standard cases. RESULTS: A total of 60 primary physicians from 7 different countries evaluated the 42 gold standard cases (without reference to the IHReS tool); 45 primary physicians evaluated these cases using the IHReS questionnaire, and 44 completed retesting using the instrument. IHReS had a sensitivity of 96.9% (95% confidence interval 96.1%-97.8%) and a specificity of 55.0% (95% confidence interval 51.0%-59.0%). The positive predictive value and negative predictive value were 40.5% and 98.3%, respectively. Validation by experts and primary physicians revealed substantial agreement for interrater reliability and intrarater repeatability. CONCLUSIONS: IHReS, a 2-part algorithm with a total of 12 questions, is an easy-to-use tool for primary physicians for the purpose of facilitating correct and timely referral of patients with IH. IHReS may help practitioners in their decision to refer patients to expert centers.

Topical sirolimus 0.1% for treating cutaneous microcystic lymphatic malformations in children and adults (TOPICAL): protocol for a multicenter phase 2, within-person, randomized, double-blind, vehicle-controlled clinical trial.

BACKGROUND: Cutaneous microcystic lymphatic malformations (CMLMs) are rare conditions in children and adults. They present as clusters of vesicles full of lymph and blood to various extents, inducing maceration, esthetic impairment, pain, and impaired quality of life. The treatment is challenging. Sirolimus is an inhibitor of mammalian target of rapamycin (mTOR) involved in angio-lymphangiogenesis. Topical sirolimus has recently been reported as effective in a few reports of patients with CMLMs. The objective is to compare the efficacy and safety of a 12-week application of 0.1% topical sirolimus versus topical vehicle in CMLMs in children and adults. METHODS: This French blinded multicenter within-person randomized controlled phase 2 trial aims to include 55 patients aged ≥ 6 years who have a primary CMLM. The CMLM will be divided into two equal areas that will be randomly allocated to 0.1% topical sirolimus or topical vehicle applied for 12 weeks. At the end of the 12-week period, the patient/parent will treat the whole area of CMLM with 0.1% topical sirolimus on remaining lesions, for eight more weeks. Patients will be seen at week 20 (treatment will be stopped) and at month 12 to evaluate long-term efficacy. The primary outcome will be improvement of the CMLM in the area treated with topical sirolimus compared to the area treated with topical vehicle by the investigator physician (blinded to the treatment) with the Physician Global Assessment score at week 12. Secondary outcomes will include: assessment of efficacy by independent experts on the basis of standardized photographs; impact on quality of life; efficacy for oozing, bleeding, erythema, and thickness evaluated by the investigators; and global efficacy as well as efficacy for functional and aesthetic impairment evaluated by the patient. Systemic passage of sirolimus will be measured at weeks 6, 12, and 20, and at week 16 for CMLMs ≥ 900 cm2. DISCUSSION: For patients with CMLMs, topical sirolimus could be a non-invasive and well-tolerated therapeutic option. If the trial demonstrates efficacy and safety of this treatment, this result will lead to a real change in the management of this condition, and 0.1% sirolimus cream would become the first-line treatment. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03972592. Registered on 3 June 2019. EU Clinical Trials Register EudraCT, 2018-001359-11.

Propranolol pharmacokinetics in infants treated for Infantile Hemangiomas requiring systemic therapy: Modeling and dosing regimen recommendations.

Propranolol has become the first choice therapy for complicated Infantile Hemangiomas (IH). The pharmacokinetics of propranolol were evaluated after repeated oral administration of a new pediatric solution of propranolol at 3 mg kg-1 day-1 given twice daily (BID) in infants (77-243 days) with IH. A population model was built to describe the pharmacokinetics of propranolol in infants and to simulate different dosing regimens. One hundred and sixty-seven plasma concentrations from 22 infants were used in the population analysis. Weight effect was tested on apparent clearance and volume of distribution. Monte-Carlo simulations were performed for 4 dosing regimens: BID dosing with irregular or strict 12-hour intervals and 2 different 3 time daily dosing (TID) regimens. The best model was a one-compartment model with first-order absorption and elimination rates. The weight affected the clearance but not the volume. Typical oral clearance was estimated at 3.06 L hour-1 kg-1 (95% CI: 1.14-8.61 L hour-1 kg-1), close to adult clearance data. When regular BID dosing was compared to TID or irregular BID regimens, simulated median Cmin and Cmax were <20% different. To conclude, a model using a weight allometric function on clearance was established and confirmed that the dose in mg/kg should be used without adaptation by range of age in treatment of complicated IH. The simulations support the use of a BID dosing preferably to a TID dosing thanks to close Cmin and Cmax at steady state between both regimen and showed the possibility of irregular BID dosing, allowing early administration in the evening when needed.

[Benign aggressive vascular anomalies in children]. / Anomalies vasculaires bénignes agressives de l'enfant et de l'adolescent.

Superficial vascular anomalies constitute a large group of malformative and tumoral conditions developed from all types of vessels. Vascular tumors are the result of cellular hyperplasia, whereas vascular malformations (VMs) are constituted of dysplastic vessels. The classification from International Society for the Study of Vascular Anomalies (ISSVA) is based on this pathogenic difference. The most common vascular tumor is infantile hemangioma, which treatment, when necessary, is propranolol. Congenital hemangiomas and tumors that might be complicated with Kasabach-Merritt phenomenon, i.e. deep thrombocytopenia, are much rarer. Management of Kasabach-Merritt phenomenon is now largely based on sirolimus. Low-flow VMs include capillary, venous and lymphatic malformations; arteriovenous malformations are high-flow malformations. These different types of VMs might be combined. Currently, there is an increasing work in delineating the different entities based on molecular findings. Treatment of VMs depends on the impairment linked to them, and is decided case by case, in pluridisciplinary consultations. Interventional treatments, especially surgery and sclerotherapy, are usually partially efficient, and management of patients with VMs increasingly involves medical drugs. First-line treatment of coagulation disorders associated with venous malformations is based on low molecular weight heparin; sirolimus seems efficient in hemorrhagic complications refractory to usual treatment. Sirolimus is about to become the standard treatment in painful inflammatory manifestations of mixed and/or complicated lymphatic malformations.

Lessons of a day hospital: Comprehensive assessment of patients with albinism in a European setting.

Albinism is a rare genetic disease, comprising syndromic and non-syndromic forms. We assessed clinical and genetic characteristics in a prospective evaluation of 64 patients (33 children and 31 adults) seen at a specialized day hospital. Causative genetic mutations were found in TYR (23/64, 35.9%), OCA2 (19/64, 29.7%), TYRP1 (1/64, 1.6%), SLC45A2 (12/64, 18.7%), C10orf11 (1/64, 1.6%), HPS1 (3/64, 4.7%), HPS5 (1/64, 1.5%), HPS6 (1/64, 1.6%) and GPR143 (2/64, 3.1%). Causative mutations remained undetermined for one patient (1.6%). Heterogeneity for hair and skin phenotype was noted across and within the different genotypes. Skin and hair hypopigmentation did not correlate with visual impairment. The diagnosis of unrecognized syndromic forms and of cases of ocular albinism in this prospective and comprehensive series of patients with albinism in a European setting is remarkable. Photoprotection was overall good but not optimal.

Germline Loss-of-Function Mutations in EPHB4 Cause a Second Form of Capillary Malformation-Arteriovenous Malformation (CM-AVM2) Deregulating RAS-MAPK Signaling.

BACKGROUND: Most arteriovenous malformations (AVMs) are localized and occur sporadically. However, they also can be multifocal in autosomal-dominant disorders, such as hereditary hemorrhagic telangiectasia and capillary malformation (CM)-AVM. Previously, we identified RASA1 mutations in 50% of patients with CM-AVM. Herein we studied non-RASA1 patients to further elucidate the pathogenicity of CMs and AVMs. METHODS: We conducted a genome-wide linkage study on a CM-AVM family. Whole-exome sequencing was also performed on 9 unrelated CM-AVM families. We identified a candidate gene and screened it in a large series of patients. The influence of several missense variants on protein function was also studied in vitro. RESULTS: We found evidence for linkage in 2 loci. Whole-exome sequencing data unraveled 4 distinct damaging variants in EPHB4 in 5 families that cosegregated with CM-AVM. Overall, screening of EPHB4 detected 47 distinct mutations in 54 index patients: 27 led to a premature stop codon or splice-site alteration, suggesting loss of function. The other 20 are nonsynonymous variants that result in amino acid substitutions. In vitro expression of several mutations confirmed loss of function of EPHB4. The clinical features included multifocal CMs, telangiectasias, and AVMs. CONCLUSIONS: We found EPHB4 mutations in patients with multifocal CMs associated with AVMs. The phenotype, CM-AVM2, mimics RASA1-related CM-AVM1 and also hereditary hemorrhagic telangiectasia. RASA1-encoded p120RASGAP is a direct effector of EPHB4. Our data highlight the pathogenetic importance of this interaction and indicts EPHB4-RAS-ERK signaling pathway as a major cause for AVMs.

Infantile haemangioma.

With a prevalence of 4·5%, infantile haemangiomas are the most common benign tumours of infancy, arising in the first few weeks of life and exhibiting a characteristic sequence of growth and spontaneous involution. Most infantile haemangiomas do not require therapy. However, to identify at-risk haemangiomas, close follow-up is crucial in the first weeks of life; 80% of all haemangiomas reach their final size by 3 months of age. The main indications for treatment are life-threatening infantile haemangioma (causing heart failure or respiratory distress), tumours posing functional risks (eg, visual obstruction, amblyopia, or feeding difficulties), ulceration, and severe anatomic distortion, especially on the face. Oral propranolol is now the first-line treatment, which should be administered as early as possible to avoid potential complications. Haemangioma shrinkage is rapidly observed with oral propranolol, but a minimum of 6 months of therapy is recommended.

Blue Rubber Bleb Nevus (BRBN) Syndrome Is Caused by Somatic TEK (TIE2) Mutations.

Blue rubber bleb nevus syndrome (Bean syndrome) is a rare, severe disorder of unknown cause, characterized by numerous cutaneous and internal venous malformations; gastrointestinal lesions are pathognomonic. We discovered somatic mutations in TEK, the gene encoding TIE2, in 15 of 17 individuals with blue rubber bleb nevus syndrome. Somatic mutations were also identified in five of six individuals with sporadically occurring multifocal venous malformations. In contrast to common unifocal venous malformation, which is most often caused by the somatic L914F TIE2 mutation, multifocal forms are predominantly caused by double (cis) mutations, that is, two somatic mutations on the same allele of the gene. Mutations are identical in all lesions from a given individual. T1105N-T1106P is recurrent in blue rubber bleb nevus, whereas Y897C-R915C is recurrent in sporadically occurring multifocal venous malformation: both cause ligand-independent activation of TIE2, and increase survival, invasion, and colony formation when expressed in human umbilical vein endothelial cells.