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Dive into the research topics where Michael Frost is active.

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Featured researches published by Michael Frost.


The Lancet | 2013

Efficacy and safety of everolimus for subependymal giant cell astrocytomas associated with tuberous sclerosis complex (EXIST-1): a multicentre, randomised, placebo-controlled phase 3 trial

David Neal Franz; Elena Belousova; Steven Sparagana; E. Martina Bebin; Michael Frost; Rachel Kuperman; Olaf Witt; Michael Kohrman; J. Robert Flamini; Joyce Y. Wu; Paolo Curatolo; Petrus J. de Vries; Vicky Whittemore; Elizabeth A. Thiele; James Ford; Gaurav D. Shah; Helene Cauwel; David Lebwohl; Tarek Sahmoud; Sergiusz Jozwiak

BACKGROUND Tuberous sclerosis complex is a genetic disorder leading to constitutive activation of mammalian target of rapamycin (mTOR) and growth of benign tumours in several organs. In the brain, growth of subependymal giant cell astrocytomas can cause life-threatening symptoms--eg, hydrocephalus, requiring surgery. In an open-label, phase 1/2 study, the mTOR inhibitor everolimus substantially and significantly reduced the volume of subependymal giant cell astrocytomas. We assessed the efficacy and safety of everolimus in patients with subependymal giant cell astrocytomas associated with tuberous sclerosis complex. METHODS In this double-blind, placebo-controlled, phase 3 trial, patients (aged 0-65 years) in 24 centres in Australia, Belgium, Canada, Germany, the UK, Italy, the Netherlands, Poland, Russian Federation, and the USA were randomly assigned, with an interactive internet-response system, in a 2:1 ratio to oral everolimus 4·5 mg/m(2) per day (titrated to achieve blood trough concentrations of 5-15 ng/mL) or placebo. Eligible patients had a definite diagnosis of tuberous sclerosis complex and at least one lesion with a diameter of 1 cm or greater, and either serial growth of a subependymal giant cell astrocytoma, a new lesion of 1 cm or greater, or new or worsening hydrocephalus. The primary endpoint was the proportion of patients with confirmed response--ie, reduction in target volume of 50% or greater relative to baseline in subependymal giant cell astrocytomas. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00789828. FINDINGS 117 patients were randomly assigned to everolimus (n=78) or placebo (n=39). 27 (35%) patients in the everolimus group had at least 50% reduction in the volume of subependymal giant cell astrocytomas versus none in the placebo group (difference 35%, 95% CI 15-52; one-sided exact Cochran-Mantel-Haenszel test, p<0·0001). Adverse events were mostly grade 1 or 2; no patients discontinued treatment because of adverse events. The most common adverse events were mouth ulceration (25 [32%] in the everolimus group vs two [5%] in the placebo group), stomatitis (24 [31%] vs eight [21%]), convulsion (18 [23%] vs ten [26%]), and pyrexia (17 [22%] vs six [15%]). INTERPRETATION These results support the use of everolimus for subependymal giant cell astrocytomas associated with tuberous sclerosis. Additionally, everolimus might represent a disease-modifying treatment for other aspects of tuberous sclerosis. FUNDING Novartis Pharmaceuticals.


The Lancet | 2013

Everolimus for angiomyolipoma associated with tuberous sclerosis complex or sporadic lymphangioleiomyomatosis (EXIST-2): a multicentre, randomised, double-blind, placebo-controlled trial

John J. Bissler; J. Christopher Kingswood; Elzbieta Radzikowska; Bernard A. Zonnenberg; Michael Frost; Elena Belousova; Matthias Sauter; Norio Nonomura; Susanne Brakemeier; Petrus J. de Vries; Vicky Whittemore; David Chen; Tarek Sahmoud; Gaurav D. Shah; Jeremie Lincy; David Lebwohl; Klemens Budde

BACKGROUND Angiomyolipomas are slow-growing tumours associated with constitutive activation of mammalian target of rapamycin (mTOR), and are common in patients with tuberous sclerosis complex and sporadic lymphangioleiomyomatosis. The insidious growth of these tumours predisposes patients to serious complications including retroperitoneal haemorrhage and impaired renal function. Everolimus, a rapamycin derivative, inhibits the mTOR pathway by acting on the mTOR complex 1. We compared the angiomyolipoma response rate on everolimus with placebo in patients with tuberous sclerosis or sporadic lymphanioleiomyomatosis-associated angiomyolipomata. METHODS In this double-blind, placebo-controlled, phase 3 trial, patients aged 18 years or older with at least one angiomyolipoma 3 cm or larger in its longest diameter (defined by radiological assessment) and a definite diagnosis of tuberous sclerosis or sporadic lymphangioleiomyomatosis were randomly assigned, in a 2:1 fashion with the use of an interactive web response system, to receive oral everolimus 10 mg per day or placebo. The primary efficacy endpoint was the proportion of patients with confirmed angiomyolipoma response of at least a 50% reduction in total volume of target angiomyolipomas relative to baseline. This study is registered with ClinicalTrials.gov number NCT00790400. RESULTS 118 patients (median age 31·0 years; IQR 18·0–61·0) from 24 centres in 11 countries were randomly assigned to receive everolimus (n=79) or placebo (n=39). At the data cutoff, double-blind treatment was ongoing for 98 patients; two main reasons for discontination were disease progression (nine placebo patients) followed by adverse events (two everolimus patients; four placebo patients). The angiomyolipoma response rate was 42% (33 of 79 [95% CI 31–53%]) for everolimus and 0% (0 of 39 [0–9%]) for placebo (response rate difference 42% [24–58%]; one-sided Cochran-Mantel-Haenszel test p<0·0001). The most common adverse events in the everolimus and placebo groups were stomatitis (48% [38 of 79], 8% [3 of 39], respectively), nasopharyngitis (24% [19 of 79] and 31% [12 of 39]), and acne-like skin lesions (22% [17 of 79] and 5% [2 of 39]). INTERPRETATION Everolimus reduced angiomyolipoma volume with an acceptable safety profile, suggesting it could be a potential treatment for angiomyolipomas associated with tuberous sclerosis. FUNDING Novartis Pharmaceuticals.


The Journal of Pediatrics | 1980

X-linked mental retardation, macro-orchidism, and the Xq27 fragile site

Gillian Turner; Art Daniel; Michael Frost

Twenty-three families with X-linked mental retardation were examined for the presence of a fragil site on the long arm of the X chromosome (Xq27 fra). Specific culture media were necessary to demonstrate this site. In only seven of the families was the Xq fragile site observed; in these, all of the affected males had both the fragile X and macro-orchidism. Macro-orchidism was not observed in the remaining 16 families. In the families with Xq27 fra segregating the fraes. This correlated with the age of the carrier. The 25 affected males with macro-orchidism and Xq27 fra had some minor clinical features in common: there was an increase in birth weight, high forehead, prognathism, pale irides, big ears, and an increased head circumference in infancy and childhood which did not persist into adult life. The majority of the affected individuals were moderately retarded.


Epilepsia | 2002

Vagus Nerve Stimulation in Children with Refractory Seizures Associated with Lennox–Gastaut Syndrome

Michael Frost; John R. Gates; Sandra L. Helmers; James W. Wheless; Paul Levisohn; Carmelo Tardo; Joan A. Conry

Summary:  Purpose: Vagus nerve stimulation (VNS) is approved for use for refractory partial seizures. Nevertheless, information regarding VNS therapy for special populations, including Lennox–Gastaut syndrome (LGS) is limited. We discuss the effectiveness, tolerability, and safety of VNS therapy in patients with LGS.


Journal of Child Neurology | 2001

Vagus nerve stimulation therapy in pediatric patients with refractory epilepsy: retrospective study.

Sandra L. Helmers; James W. Wheless; Michael Frost; John Gates; Paul Levisohn; Carmelo Tardo; Joan A. Conry; Dilek Yalnızoğlu; Joseph R. Madsen

This six-center, retrospective study evaluated the effectiveness, tolerability, and safety of vagus nerve stimulation in children. Data were available for 125 patients at baseline, 95 patients at 3 months, 56 patients at 6 months, and 12 patients at 12 months. The typical patient, aged 12 years, had onset of seizures at age 2 years and had tried nine anticonvulsants before implantation. Collected data included preimplant history, seizures, implant, device settings, quality of life, and adverse events. Average seizure reduction was 36.1% at 3 months and 44.7% at 6 months. Common adverse events included voice alteration and coughing during stimulation. Rare adverse events, unique to this age group, included increased drooling and increased hyperactivity. Quality of life improved in alertness, verbal communication, school performance, clustering of seizures, and postictal periods. We concluded that vagus nerve stimulation is an effective treatment for medically refractory epilepsy in children. (J Child Neurol 2001;16:843—848).


Lancet Oncology | 2014

Everolimus for subependymal giant cell astrocytoma in patients with tuberous sclerosis complex: 2-year open-label extension of the randomised EXIST-1 study

David Neal Franz; Elena Belousova; Steven Sparagana; E. Martina Bebin; Michael Frost; Rachel Kuperman; Olaf Witt; Michael Kohrman; J. Robert Flamini; Joyce Y. Wu; Paolo Curatolo; Petrus J. de Vries; Noah Berkowitz; Oezlem Anak; Julie Niolat; Sergiusz Jozwiak

BACKGROUND In the EXIST-1 trial, initiated on Aug 10, 2009, more than 35% of patients with subependymal giant cell astrocytoma (SEGA) associated with tuberous sclerosis complex had at least 50% reduction in SEGA volume after 9·6 months of treatment with everolimus. In this Article, we report interim data (up to Jan 11, 2013) to support longer-term tolerability and efficacy of everolimus from the continuing 4-year extension phase of EXIST-1. METHODS We assessed data from a prospective, open-label extension of a multicentre, phase 3, randomised, double-blind, placebo-controlled study in patients with tuberous sclerosis complex who had SEGA that was growing and needed treatment. In this extension study, we included all patients who had been assigned everolimus during the double-blind, randomised phase of the trial and those patients who crossed over from the placebo group to receive everolimus during the randomised phase or at the start of the extension phase. All patients received oral everolimus at a starting dose of 4·5 mg/m(2) per day. Everolimus dose was subsequently adjusted subject to tolerability to attain blood trough concentrations of 5-15 ng/mL. An independent central radiology review team assessed SEGA response (at least a 50% reduction from baseline in total volume of all target SEGAs; the primary endpoint) by MRI at 12, 24, and 48 weeks, then every year thereafter in all patients who received at least one dose of everolimus. This study was registered with ClinicalTrials.gov, number NCT00789828. FINDINGS Of the original 117 randomly assigned patients, 111 were given everolimus between Aug 20, 2009, and Jan 11, 2013 (date of data cutoff); we included these patients in our longer-term analysis. Median duration of everolimus exposure was 29·3 months (IQR 19·4-33·8). Median follow-up was 28·3 months (IQR 19·3-33·0). 54 (49%) patients had a response of 50% or greater reduction in SEGA volume (95% CI 39·0-58·3), and duration of response was between 2·1 and 31·1 months (median not reached). SEGA volume was reduced by 50% or more in 39 (37%) of 105 patients at 24 weeks, 48 (46%) of 104 patients at 48 weeks, 36 (47%) of 76 patients at 96 weeks, and 11 (38%) of 29 patients at 144 weeks. Stomatitis (48 [43%] patients) and mouth ulceration (33 [30%] patients) were the most frequent treatment-related adverse events; infections were the most commonly reported treatment-related serious adverse event, occurring in 15 (14%) patients. 35 (32%) patients reported treatment-related grade 3 or 4 adverse events, the most common of which were stomatitis (nine [8%]) and pneumonia (nine [8%]). 18 (16%) patients had treatment-related serious adverse events. Six (5%) patients withdrew because of adverse events. INTERPRETATION These results support the longer-term use of everolimus in patients who have few treatment options and who need continued treatment for tuberous sclerosis complex and its varied manifestations. Reduction or stabilisation of tumour volume with everolimus will hopefully provide long-term clinical benefit in patients with SEGA. FUNDING Novartis Pharmaceuticals.


Epilepsia | 2009

Magnetic resonance imaging abnormalities associated with vigabatrin in patients with epilepsy

James W. Wheless; Lionel Carmant; Martina Bebin; Joan A. Conry; Catherine Chiron; Roy D. Elterman; Michael Frost; Juliann M. Paolicchi; W. Donald Shields; Elizabeth A. Thiele; Mary L. Zupanc; Stephen D. Collins

Purpose:  Vigabatrin used to treat infantile spasms (IS) has been associated with transient magnetic resonance imaging (MRI) abnormalities. We carried out a retrospective review to better characterize the frequency of those abnormalities in IS and in children and adults treated with vigabatrin for refractory complex partial seizures (CPS).


Nephrology Dialysis Transplantation | 2016

Everolimus for renal angiomyolipoma in patients with tuberous sclerosis complex or sporadic lymphangioleiomyomatosis: extension of a randomized controlled trial

John J. Bissler; John C. Kingswood; Elzbieta Radzikowska; Bernard A. Zonnenberg; Michael Frost; Elena Belousova; Matthias Sauter; Norio Nonomura; Susanne Brakemeier; Petrus J. de Vries; Noah Berkowitz; Sara Miao; Scott Segal; Severine Peyrard; Klemens Budde

BACKGROUND Mammalian target of rapamycin (mTOR) inhibitors are recommended as first-line treatment of renal angiomyolipoma associated with tuberous sclerosis complex (TSC) or sporadic lymphangioleiomyomatosis (sporadic LAM), but follow-up is limited. Longer term efficacy and tolerability data from a Phase 3, double-blind, placebo-controlled trial are presented. METHODS Following favorable results from the primary analysis (data cutoff 30 June 2011) of the EXIST-2 trial, patients still receiving study treatment were allowed to enter an open-label extension. Everolimus was initiated at 10 mg once daily and titrated based on tolerability. The primary outcome was angiomyolipoma response rate (≥ 50% reduction from baseline in target lesion volumes). Safety was a secondary endpoint. RESULTS As of the cutoff date (1 May 2013), 112 patients had received everolimus, and the response rate in 107 patients with angiomyolipoma (median duration of medication exposure of 28.9 months) was 54%. The proportion of patients achieving angiomyolipoma reductions of ≥ 30% and ≥ 50% increased over time, reaching 81.6% (62/76) and 64.5% (49/76), respectively, by Week 96. No everolimus-treated patients experienced renal bleeding. The long-term safety profile was consistent with previous reports; adverse events (AEs) were mostly Grade 1/2, and there were no new safety issues. The frequency of emerging AEs and severe AEs lessened over time. CONCLUSIONS Longer term everolimus treatment appeared safe and effective in patients with TSC- or sporadic LAM-associated renal angiomyolipoma not requiring surgical intervention. Continued reduction in angiomyolipoma volume was demonstrated, and there was no angiomyolipoma-related bleeding; AEs were predictable and generally manageable. TRIAL REGISTRATION clinicaltrialsgov identifier: NCT00790400 (http://clinicaltrials.gov/ct2/show/NCT00790400).


Nephrology Dialysis Transplantation | 2014

The effect of everolimus on renal angiomyolipoma in patients with tuberous sclerosis complex being treated for subependymal giant cell astrocytoma: subgroup results from the randomized, placebo-controlled, Phase 3 trial EXIST-1

J. Chris Kingswood; Sergiusz Jozwiak; Elena Belousova; Michael Frost; Rachel Kuperman; E. Martina Bebin; Bruce R. Korf; J. Robert Flamini; Michael Kohrman; Steven Sparagana; Joyce Y. Wu; Thomas Brechenmacher; Karen Stein; Noah Berkowitz; John J. Bissler; David Neal Franz

BACKGROUND Tuberous sclerosis complex (TSC) is characterized by benign tumours in multiple organs, including the brain, kidneys, skin, lungs and heart. Our objective was to evaluate everolimus, an mTOR inhibitor, in the treatment of angiomyolipoma in patients with subependymal giant cell astrocytoma (SEGA) associated with TSC. METHODS EXamining everolimus In a Study of Tuberous Sclerosis Complex-1 (NCT00789828), a prospective, double-blind, randomized, placebo-controlled, Phase 3 study, examined everolimus in treating SEGA associated with TSC. Patients with serial SEGA growth from pre-baseline to baseline scans were randomly assigned (2:1) to receive 4.5 mg/m(2)/day everolimus (target blood trough: 5-15 ng/mL; n = 78) or placebo (n = 39). Angiomyolipoma response rates were analysed in patients (n = 44) with target baseline angiomyolipoma lesions (≥1 angiomyolipoma; longest diameter ≥1.0 cm). An angiomyolipoma response rate, defined as the proportion of patients with confirmed angiomyolipoma response, was assessed by kidney CT or MRI screening at baseline, at 12, 24 and 48 weeks and annually. RESULTS Angiomyolipoma response rates were 53.3% (16/30) and 0% (0/14) for everolimus- and placebo-treated patients, respectively. Angiomyolipoma reductions ≥50% in the sum of volumes of all target lesions were seen only in everolimus-treated patients (56.5, 78.3 and 80.0%) compared with placebo-treated patients (0% at each time point) at Weeks 12, 24 and 48, respectively. Greater percentages of everolimus-treated patients had angiomyolipoma reductions ≥30% at these same time points (82.6, 100 and 100% versus 8.3, 18.2 and 16.7% for everolimus versus placebo, respectively). CONCLUSIONS Everolimus showed efficacy in reducing angiomyolipoma lesion volume in patients with SEGA associated with TSC.The trial is registered with ClinicalTrials.gov, number NCT00789828; http://clinicaltrials.gov/ct2/show/NCT00789828?term=EXIST-1&rank=1.


The Lancet | 2018

Cannabidiol in patients with seizures associated with Lennox-Gastaut syndrome (GWPCARE4): a randomised, double-blind, placebo-controlled phase 3 trial

Elizabeth A. Thiele; Eric D. Marsh; Jacqueline A French; Maria Mazurkiewicz-Bełdzińska; Selim R Benbadis; Charuta Joshi; Paul D. Lyons; Adam Taylor; Claire Roberts; Kenneth W. Sommerville; Boudewjin Gunning; Jacek Gawlowicz; Pawel Lisewski; Maria Mazurkiewicz Beldzinska; Krystyna Mitosek Szewczyk; Barbara Steinborn; Marta Zolnowska; Elaine Hughes; Ailsa McLellan; Selim R. Benbadis; Michael A. Ciliberto; Gary G. Clark; Dennis J. Dlugos; Francis M. Filloux; Robert Flamini; Jacqueline A. French; Michael Frost; Sheryl R. Haut; Siddarth Kapoor; Sudha Kilaru Kessler

BACKGROUND Patients with Lennox-Gastaut syndrome, a rare, severe form of epileptic encephalopathy, are frequently treatment resistant to available medications. No controlled studies have investigated the use of cannabidiol for patients with seizures associated with Lennox-Gastaut syndrome. We therefore assessed the efficacy and safety of cannabidiol as an add-on anticonvulsant therapy in this population of patients. METHODS In this randomised, double-blind, placebo-controlled trial done at 24 clinical sites in the USA, the Netherlands, and Poland, we investigated the efficacy of cannabidiol as add-on therapy for drop seizures in patients with treatment-resistant Lennox-Gastaut syndrome. Eligible patients (aged 2-55 years) had Lennox-Gastaut syndrome, including a history of slow (<3 Hz) spike-and-wave patterns on electroencephalogram, evidence of more than one type of generalised seizure for at least 6 months, at least two drop seizures per week during the 4-week baseline period, and had not responded to treatment with at least two antiepileptic drugs. Patients were randomly assigned (1:1) using an interactive voice response system, stratified by age group, to receive 20 mg/kg oral cannabidiol daily or matched placebo for 14 weeks. All patients, caregivers, investigators, and individuals assessing data were masked to group assignment. The primary endpoint was percentage change from baseline in monthly frequency of drop seizures during the treatment period, analysed in all patients who received at least one dose of study drug and had post-baseline efficacy data. All randomly assigned patients were included in the safety analyses. This study is registered with ClinicalTrials.gov, number NCT02224690. FINDINGS Between April 28, 2015, and Oct 15, 2015, we randomly assigned 171 patients to receive cannabidiol (n=86) or placebo (n=85). 14 patients in the cannabidiol group and one in the placebo group discontinued study treatment; all randomly assigned patients received at least one dose of study treatment and had post-baseline efficacy data. The median percentage reduction in monthly drop seizure frequency from baseline was 43·9% (IQR -69·6 to -1·9) in the cannibidiol group and 21·8% (IQR -45·7 to 1·7) in the placebo group. The estimated median difference between the treatment groups was -17·21 (95% CI -30·32 to -4·09; p=0·0135) during the 14-week treatment period. Adverse events occurred in 74 (86%) of 86 patients in the cannabidiol group and 59 (69%) of 85 patients in the placebo group; most were mild or moderate. The most common adverse events were diarrhoea, somnolence, pyrexia, decreased appetite, and vomiting. 12 (14%) patients in the cannabidiol group and one (1%) patient in the placebo group withdrew from the study because of adverse events. One patient (1%) died in the cannabidiol group, but this was considered unrelated to treatment. INTERPRETATION Add-on cannabidiol is efficacious for the treatment of patients with drop seizures associated with Lennox-Gastaut syndrome and is generally well tolerated. The long-term efficacy and safety of cannabidiol is currently being assessed in the open-label extension of this trial. FUNDING GW Pharmaceuticals.

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Elena Belousova

Russian National Research Medical University

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John J. Bissler

University of Tennessee Health Science Center

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David Neal Franz

Cincinnati Children's Hospital Medical Center

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Steven Sparagana

Texas Scottish Rite Hospital for Children

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