34th EMWA Conference Clinical and Operational Challenges of Paediatric Clinical Trials (Seminar) Dr. med. Klaus Rose, M.D., M.S. Pediatric Drug Development & More klausrose Consulting klaus.rose@klausrose.net 1 Agenda • • • • • Children are different from adults: physiology Children are different from adults: ADME Pediatric clinical trials Existing & evolving structures for pediatric clinical trials Relevant international guidelines klaus.rose@klausrose.net 2 Agenda • • • • • Children are different from adults: physiology Children are different from adults: ADME Pediatric clinical trials Existing & evolving structures for pediatric clinical trials Relevant international guidelines klaus.rose@klausrose.net 3 Preterm Newborn: Phase of survival born at < 36 weeks of gestation Physiology: Large body surface Increased skin permeability Reduced surfactant synthesis Aortopulmonary shunts Immaturity of the brain stem No ciruclatory autoregulation Incomplete retinal vascularisation Very Preterm Newborn: Phase of survival born at < 36 weeks of gestation Pathophysiology: Respiratory distress Pulmonary hypertension Patent ductus arteriosus Apnea Intraventricular hemorrhage Retinopathy of prematurity (ROP) Bronchopulmonary dysplasia Term Newborn: Phase of Adaptation age: birth up to 1 month Physiology: Large body surface Increased skin permeability Increased body water Decreased blood brain barrier Incomplete neuronal maturation Increased hemolysis Term Newborn: Phase of Adaptation age: birth up to 1 month Pathophysiology: Sepsis Hyperbilirubinemia Seizures Hypocalcemia Hypoglycemia Malformations Infants and Toddler: Phase of proliferation and growth age: 22 days to 24 months Physiology: Small airways Ongoing cerebral myelination Naive (incompetent) immune system Large liver and kidney (increased clearances) Infants and Toddler: Phase of proliferation and growth age: 22 days to 24 months Pathophysiology: Otitis media Bronchiolitis Febrile seizures Rickets Children: Phase of Differentiation and Training age: 2 to 11 years Physiology: Slower growth rate Increased independence Increased school performance Shift to logical operations Children: Phase of Differentiation and Training age: 2 to 11 years Pathophysiology: Accidence Dysfunctions of the immune system: Asthma/allergy Juvenile rheumatoid arthritis Autoimmune diseases Neoplasm Hyperkinesia Enuresis Organ transplantations Epileptic syndromes Obesity Diabetes Adolescents: Sexual Maturation age: 12 to 17 years Physiology: Rapid body changes: growth spurt gonadal growth Emotional instability Adolescents: Sexual Maturation age: 12 to 17 years Pathophysiology: Acne vulgaris Endocrine dysfunctions Accidence Sexual transmitted diseases Drug addiction Doping Pre-term Infant Term Newborn Infant < 36 weeks of gestation Infant/Toddler Child Adolescent 28 days -23 months 2 - 11 years 12 - 17 years Growth Training Maturation 0-27 days Adaptation Survival Seyberth, in Pädiatrie, eds Speer/Gahr, 2005 Age Groups as per ICH E 11 Preterm newborn infants (0 - 27 days) Term newborn infants (0 - 27 days) Infants and toddlers (28 days to 23 months) Children (2 - 11 years) Adolescents 12-16/17 y - 18 18 Agenda • • • • • Children are different from adults: physiology Children are different from adults: ADMET Pediatric clinical trials Existing & evolving structures for pediatric clinical trials Relevant international guidelines klaus.rose@klausrose.net 19 Key Publication Kearns, 2003, NEJM • Absorption, Distribution, Metabolization, Excretion in children are different from adults • Maturation with age is not linear and not in parallel • Variability much higher 20 ADME In Children 21 Kearns et al, NEJM 2003 Drug Absorption • • • • • • • Gastric emptying delayed in infants < 6 mo of age Gastric acid production reaches adult levels by age 3 y Gastric mucosa less developed than adults In adults, gastric emptying biphasic Preterm infant emptying slow and linear Small infants require 6-8 hrs Gastrointestinal absorption comparable to adults by 3 months Distribution: Protein binding lower in newborns • Lower albumin and a1-acid glycoprotein • Decreased affinity of fetal albumin • Endogenous competitors (e.g., bilirubin) • Local anesthetics are less protein bound • May increase free fraction - increased risk for toxicity Distribution: Increased Total Body Water • Newborn: 70% body wt vs.. 55% in adult • Larger ECF (40% v. 20% in adults) • Larger volumes of distribution (Vd) • Lower peak blood level (but same at steady state) Neonatal Analgesic Clearance Delayed • Immature hepatic enzymes • Decreased during first weeks of life: – Renal blood flow – Glomerular filtration – Tubular secretion Renal Clearance Compared to Adults: • • • • Neonates - decreased Premature infants - decreased Toddlers - increased Children - increased Renal Elimination • Preterm infants generally need lower doses (mg/kg) to maintain similar steady-state concentrations • Requires 6-12 months for renal function to reach adult values Pharmacokinetic Differences Term & Preterm Infants Absorption: Gastric HCI-production Bile flow Bacterial intestinal growth Enterohepatic circulation Distribution: Body water Body fat Muscular mass Plasma protein binding Liver metabolism: Hydroxylation Glucoronidation Renale excretion: GFR Tubular function Dosage-principle in the NICU • Given: • Vd • Clearance • Result: • Loading dose (LD) • Maintenance dose (MD) • Examples: • Phenobarbital, Phenytoin, Methylxanthine, Digoxin, Aminoglykoside, Indometacin Chloramphenicol, Furosemide Toxicity Examples Early Infancy & Childhood Target/ Organ Drug Effect Teeth tetracyclines discoloration/ enamel dysplasia Genital tract cyclophosphamide infertility/ovarian failure Immune system tacrolimus Lymphoproliferation, diabetes Heart antracyclines alkylating agents methylphenidate cardiotoxicity heart failure cardiovascular events e.g. myocardial infarction CNS phenobarbital glucocorticoides methylphenidate cisplatin attention and memory dysfunction cerebral palsy stroke hearing loss Kidney furosemide nephrocalcinosis Bone glucocorticoids growth impairment Agenda • • • • • Children are different from adults: physiology Children are different from adults: ADME Pediatric clinical trials Existing & evolving structures for pediatric clinical trials Relevant international guidelines klaus.rose@klausrose.net 31 Types of Pediatric Studies 0. 1. 2. 3. 4. Extrapolation / Modelling & Simulation PK/PD: not in healthy children phase I only in pediatric patients! Controlled clinical trials (Phase II – IV) - Active control - Placebo control - No control (e.g. rare diseases) Diagnostic studies Non-interventional studies: long-term observation; registries; epidemiological studies Other categorisation: regulatory vs. Investigator initiated clin trials FDA Pediatric Study Decision Tree Reasonable to assume (pediatrics vs adults) 3 similar disease progression? 3 similar response to intervention? YES TO BOTH NO Reasonable to assume similar concentration-response (C-R) in pediatrics and adults? •Conduct PK studies •Conduct safety/efficacy trials* NO NO Is there a PD measurement** that can be use to predict efficacy? YES •Conduct PK studies to achieve levels similar to adults •Conduct safety trials YES •Conduct PK/PD studies to get C-R for PD measurement •Conduct PK studies to achieve target concentrations based on C-R •Conduct safety trials klaus.rose@klausrose.net 34 Patient Numbers • As many patients as necessary, as few as possible • Statistical significance and clinically relevant difference in the chosen endpoint must be reached with the chosen case numbers • Rare adverse events will only be found in much larger case numbers often not possible in children! • Design with repeated measurements in the same patient might reduce number of needed patients • Look for suitable surrogate endpoints, e.g. hospitalisation rate or Δ in glomelar filtration rate for renal function Parameters Requested in PIPs (Clinical Study Form) • • • • • • • • • • • • Type of study & study design Type of control (placebo/ active control), justification, Location (regions), Test products; dose; route of administration, Objective(s) of the study, Number of patients (M/F) and per age group Duration of treatment (incl post-study observation ) Main inclusion/exclusion criteria, Endpoints (primary, secondary) Sample size (more or less detailed as appropriate), Power calculation: describe effect size expected, Options in case of recruitment issues, interim analyses and stopping rules, • Statistical methods (Statistical methods to compare groups for primary outcome & for additional analyses if relevant). klaus.rose@klausrose.net 36 Endpoint Examples Drug Indication Surrogate Endpoint ACEi, ARB, βblockers Hypertension BP lowering effect (DBP vs. SBP) Statins Hyperlipidemia LDL lowering effect Atorvastatin Atherosclerosis in children Carotid IMT with lupus Enalapril Infant Single Ventricle Growth Mitral regurgitation post AVSD repair LV end-diastolic dimension Z-score Sildenafil Pulmonary hypertension Exercise tolerance Ataluren Duchenne’s muscular dystrophy 6 min walk test Operational Challenges Clinical Trials • Recruitment & consent of parents • Rule of the thumb: recruitment the easier the more severe the disease • > 90% of children with cancer participate in trials • Parents’ associations can help recruiting Operational Challenges Clinical Trials • Patients dislike placebo control recruitment ↓ • Facilities: if shabby, will hinder recruitment • If there is no space for healthy brother to play, mother will not return • If study personnel is unfriendly, mother will not return • Monitor: should have pediatric experience • Good monitoring as essential as good protocol Blood Withdrawals • • • • Justify every drop in protocol/ to ethics committee Define upfront maximum number of tries Define priorities of exams if not enough blood Offer anesthetic cream, but child/ parents decide! Informed Consent & Assent • Use different texts for different age groups • From around 7 years on, child will understand • Child’s signature is not legally binding, but should be asked for as a token of respect • Physician can override child’s dissent if there are serious medical reasons Ethics Committees / IRBs • • • • • Have essential place between plan & execution Should have sufficient pediatric experience Not all of them know about EU pediatric legislation Not all of them focus on ethical questions Can be easy or difficult in the dialogue Laboratory/ Central Laboratory • • • • Make sure they have normal values for all ages Central Laboratory: negotiate with senior officer Central lab should have pediatric experience Define upfront priorities if not enough blood Agenda • • • • • Children are different from adults: physiology Children are different from adults: ADME Pediatric clinical trials Existing & evolving structures for pediatric clinical trials Relevant international guidelines klaus.rose@klausrose.net 44 Structures for Pediatric Clinical Research • • • • EU network of networks: EnprEMA Commercial CROs Further academic research networks National, European, US-American and International disease-specific academic networks • ESDP (European Society of Developmental Pharmacology) • ICDRA (International Conference of Drug Regulatry Authorities), coordinated by WHO klaus.rose@klausrose.net 45 European Network of Paediatric Research at the European Medicines Agency (Enpr-EMA) • Academic clinical networks, coordinated by EMA • On EMA website: Enpr-EMA workshops; • Three membership categories 1. Networks fulfilling all minimum criteria 2. Networks currently undergoing clarification 3. Networks currently not qualifying • MCRN: medicines for children research network klaus.rose@klausrose.net 46 Category 1 • • • • • • • • • • • • • • • • • • European Cystic Fibrosis Society Clinical Trials Network (ECFS-CTN) European Network for Hyperkinetic Disorders (EUNETHYDIS) European Paed Oncology Off-patent Medicines Consortium (EPOC) Finnish Investigators Network for Pediatric Medicine (FINPEDMED) German Neonatal Network (GNN) Innovative Therapies for Children with Cancer (ITCC) International BFM Study Group (I-BFM-SG) Italian Paediatric Federation MCRN (FIMP - MCRN) MCRN The Netherlands (MCRN NL) Mother Infant Child Youth Research Network, Canada (MICYRN) NIHR Medicines for Children Research Network (MCRN UK) Newcastle CCLG Pharmacology Studies Group Paediatric European Network for the Treatment of AIDS (PENTA) Pediatric Rheumatology International Trials Organisation (PRINTO) Scottish MCRN (Scotmcn) United Kingdom Paediatric Vaccines Group (UKPVG) European Group for Blood and Marrow Transplantation (EBMT) Paediatric Network of Clinical Investigation Centers - CICPed klaus.rose@klausrose.net 47 Category 2 • Children Leukemia Group (CLG) (EORTC) • Network of Excellence for Research in Paediatric Clinical Care klaus.rose@klausrose.net 48 • • • • • • • • • • • • • • Category 3 Belgian Pediatric Drug Network – BPDN EuroNeoNet Eur Soc Paed Gastronenterology, Hepatol & Nutr (ESPGHAN) Futurenest Clinical Research International Pediatric Transplant Association (IPTA) Irish Paediatric Clinical Research Network (IPCRN) Juv Scleroerma Working Group - Paed Rheumatology Eur Soc National Center Child Health and Development (NCCHD) Japan Neocirculation Paed European Network for the Treatment of Infection (PENTI) Réseau d’Investigations Pédiatriques Produits de Santé (RIPPS) Swedish Pediatric Society (BLF) Paediatric Trial Network (AMIKI) Italian Neonatal Network (INN) klaus.rose@klausrose.net 49 Levels Of External Support In Pediatric Drug Development 1 Strategic level: Reflect potential use in children [same, similar, different from adult use]. Advise on pediatric epidemiology and mechanism of disease in different age groups Clinical specialists, consultants, 2 Designing pediatric development plan 3 CROs, medical writers, (general) & write PIP (EU) regulatory/ pediatric consultants, medical writers 3. Design individual projects, e.g. clinical PedResearch Networks studies, preclinical test batteries, (EnprEMA); reg/ ped technical formulation development etc consultants, CROs 4 Execute individual projects PedResearch Networks (EnprEMA), CROs Agenda • • • • • Children are different from adults: physiology Children are different from adults: ADME Pediatric clinical trials Existing & evolving structures for pediatric clinical trials Relevant guidelines klaus.rose@klausrose.net 51 Relevant Guidelines • • • • • • ICH E 11 Declaration of Helsinki (informed consent/ assent) ICH E 6 (GCP) ICH M 3 (Definition of safe contraception) And about ten thousand more … … and national guidelines & laws klaus.rose@klausrose.net 52 ICH E 11: Clinical Investigation of Medicinal Products in the Pediatric Population* • Binding agreement world wide between industry & authorities • 2.4 Type of studies: “When a medicinal product is to be used … for the same indication(s) as … in adults, the disease process is similar…, and the outcome of therapy is likely to be comparable, extrapolation from adult efficacy data may be appropriate.“ • And: “ … extrapolation of efficacy from older to younger pediatric patients may be possible.” • 2.4.2: “The principles in study design, statistical considerations & choice of control groups … generally apply to pediatric efficacy studies. There are, however, certain features unique to pediatric studies … it may be necessary to develop, validate, and employ different endpoints for specific age & developmental subgroups.” * 53 http://www.ich.org/fileadmin/Public_Web_Site/ICH_Products/Guidelines/Efficacy/E11/Step4/E11_Guideline.pdf ICH M 3: Non-Clinical Safety Studies For Human Clinical Trials For Pharmaceuticals • Women of Child Bearing Potential (WCBP): concern for unintentional exposure of an embryo/fetus; strong EU/ US / Japan differences in timing of repro tox studies before inclusion of WCBP in clinical trials. US require highly effective method of birth control as per ICH M 3 Note 3: • “Highly effective methods of birth control are defined as those, alone or in combination, that result in a low failure rate (i.e., less than 1% per year) when used consistently and correctly. For subjects using a hormonal contraceptive method, information regarding the product under evaluation and its potential effect on the contraceptive should be addressed.“ klaus.rose@klausrose.net 55 The Declaration of Helskinki Version 2008 • Does not contain the words ‘child’ or ‘minor’ • Addresses vulnerable and incompetent research subjects • Relevant §s: 9 & 28 klaus.rose@klausrose.net 56 JUST ANNOUNCED ! Joint DIA/ EFGCP/ EMA Paediatric Forum 2012 The EU paediatric regulation in its 6th year: From Learning to Adapting 26 & 27 September 2012 London, UK Programme Committee: Gesine Bejeuhr, VfA (Association of Researchbased Pharmaceutical Companies, Germany) Irja Lutsar, PDCO member for Estonia Cecile Ollivier, EMA, London, UK Thorsten Olski, EMA, London, UK Klaus Rose, klausrose Consulting, Switzerland Thomas Severin, Novartis, Switzerland Organised by : In partnership with : Conclusions • Pediatric drug development has different meanings • Academic lecturers focus on clinical pharmacology and therapeutic outcomes • Regulators focus on legal requirements • Most companies struggle to meet legal requirements • A few companies focus on medicines for children • Some barriers against research with children have fallen, others still need to be removed klaus.rose@klausrose.net 58 Thank You For Your Attention! klaus.rose@klausrose.net 59 Back-Ups klaus.rose@klausrose.net 60 klaus.rose@klausrose.net 61 Released May 2010 klaus.rose@klausrose.net 62