FOUR NEW SQUARE LINCOLN’S INN THE CHANGING SHAPE OF PHARMACEUTICAL RISK PETER FELDSCHREIBER
A Brief History • 120 B.C: Mithradatum/Galene – global panacea, efficacy and safety trials on condemned prisoners • 1450: manufacture supervised by 4 inspectors appointed under Apothecary, Wares, Drugs and Stuffs Act (c 32 Henry VIII c. 40 for Physicians and their privileges). • 1665: The Great Plague; Royal College of Physician’s advice: ‘..for the cure of the plague and preventing infection, treat with plaster of galene applied three times daily…’ • 1746: Criticism of efficacy, last reference in the London Pharmacopeia
History (2) • 1853 – 1871: Following increasing concerns as to safety of smallpox vaccination, local authorities employed vaccination officers to ensure quality.Commons select committee investigating efficiency of vaccination system recorded concern regarding transmission of syphilis. • BMA statement : ‘The duty of the Association, at once, without any necessary delay is to satisfy the public that all is being done to discover the means by which anaesthesia may be rendered safe for the future.’
History (3) • 1907: Board of Trade issue manufacturing licenses to control quality of Salvarsan. Each batch submitted to MRC for approval prior to marketing • 1917: Venereal Diseases Act • 1922: Salvarsan sub-committee of Parliamentary Select Committee on Patent Medicines investigate Salvarsan induced jaundice: ‘The Committee hope that a statement of the rare fatalities and other untoward effects of arsenobenzol may encourage the communication to the Ministry of Health of details concerning such accidents for it is only in the light of such information that investigation and measures to their presentation can be undertaken.’ • 1925: Therapeutic Substances Act Part 1 introduced regulation of manufacture of biological substances • 1939: Cancer Act; prohibited public advertisements and promotion of drugs in order to protect sufferers from inadequate or unsuitable treatment and fraudulent claims of efficacy • 1956: Part II added to control, sale and supply of medicinal products. Schedule 1 included sera toxins and antibodies.
Overview 120 B.C. - 1956 • Predominantly control of quality, although sporadic references and concerns regarding safety and efficacy. However latter directed towards ‘manufacturing defects’. • No consistent systematic attempt to define and evaluate intrinsic safety and efficacy of new medicines even in face of major developments on pharmacology e.g. insulin, antibiotics, neurochemical transmitters etc. No regulatory concept of risk : benefit assessment
And then came Thalidomide • 1953 – 1956: Synthesis and manufacture in West Germany: ‘ • 1957 Advertisement: ‘Does not damage either mother or child’ • 1959: neuropathy reported during early use • 1960: CNS toxicity • 1961: McBride letter, Australia • 10,000 babies world wide with phocomelia
Manufacturer’s response • Denied any causal relationship despite the scale of the disaster • Postulated causes included watching television, radioactive fall out from atomic bomb tests • Recent drug withdrawals have prompted similar responses
Regulatory and clinical responses • 2nd December 1961: Drug withdrawn from UK • 9 months later wave of malformations disappeared • 1962 Joint Sub-Committee of the English and Scottish Standing Medical Advisory Committees • Identified need for adequate pharmacology and safety and efficacy testing before release of new medicines into general use. Also need for early detection of adverse effects arising after release and to keep doctors informed
1961 - 1963 • UK accept key recommendations: • Responsibility for experimental animal testing prior to clinical trials remains with pharma manufacturer • Expert advisory body to review evidence and offer advice on toxicity of new drugs • June 1963 Committee on Safety of Drugs formed
1965 - 1966 • Manufacturers challenge right of CSD to require evidence of efficacy. Committee reiterate that for serious diseases failure of efficacy constitutes unacceptable risk – first expression of risk : benefit assessment • Phenacetin: high doses recognised as cause of renal damage • Committee recognises problems of drug interactions: adrenaline interacting with MAOI anti-depressants
1966 onwards • Voluntary reporting of yellow cards and computerised adverse reactions on-line information systems • Identified methyl dopa as cause of haemolytic anaemia • Pressurised aerosols of broncholdilators for asthma become prescription only medicines. • Withdrawal of pronethalol and phenopropazine • Ibufenac withdrawn due to hepatotoxicity • 1968 – oral contraceptives induced thromboembolism
Medicines Act 1968 • Comprehensive measures to replace most previous legislation re control of medicines • Now consistent with European Law
Scientific developments post thalidomide • Greater sophistication in assessing risk : benefit: improved clinical trial methodology and statistical techniques • Evaluation of causality • Pharmacogenomics – uses genetic information to predict individual responses to drugs. • International harmonisation of clinical trials
Regulatory Structure and Function post-thalidomide (1) • Current framework only 50 years old and has developed piecemeal. • Function of the regulator is to: - protect the public health by allowing only medicines which have a satisfactory risk : benefit profile to be marketed and remain so;- to provide information to prescribers so that these products can be used safely and effectively; - not to put unnecessary hurdles in the way of the development of innovative products
Regulatory Structure and Function post-thalidomide (2) • Regulation must follow science • Drug development has changed out of all recognition in the last 50 years • Regulators now recognise that, at the time of licensing, the risk-benefit profile may not be the same as when the drug has been in extensive use in the population at large. Risk : benefit has to be assessed iteratively during its life cycle.
Ongoing problems and challenges • Cox 2 inhibitors: Withdrawal of these, e.g. Vioxx, is an important watershed in terms of medicine regulation. Emphasises the importance of mandatory pharmaco-vigilance and risk minimisation strategies. • Monoclonal antibodies: Herceptin, now recognise changing risk-benefit depending on indication for use; Cardiotoxicity of herceptin may be acceptable in advanced breast cancer but use in early cancer may pose unacceptable risk of cardiac damage.TGN1412, the Northwick Park catastrophe: need for better pre-clinical assessment of mechanisms of action and more appropriately designed pre-clinical studies
Re-emergence of Thalidomide • 1998: Approved for complications of leprosy • Available ‘off – label’ HIV/AIDS related conditions, autoimmune diseases, cancer – multiple myeloma, primary brain tumours • Current research in Crohn’s disease, rheumatoid arthritis • Need to monitor exposure in women of child-bearing age • Ethical issues in marketing known teratogen
Lessons to be learnt • Current regulatory system may have intrinsic defects of structure and function • Structure: System may not be able to accommodate requirements of consumer protection legislation as regards product liability. • Function: methodology for evaluating risk : benefit may not be sufficiently robust for assessment of new therapeutic modes of action, e.g. monoclonal antibodies. Need for ‘bespoke’ risk assessment from earliest stages of drug development
Improvement of the Regulatory system • Two stage approach: • Objective evaluation of risk : benefit by scientific experts followed by • Patient/lay representation in final approval of marketing authorisation
Epilogue • The risk has not changed • The perception of the risk and risk-benefit of new medicines is constantly changing • How can society improve the mechanisms of understanding and accepting risk so that new, potentially life saving medicines can be brought to the population?
THE CHANGING SHAPE OF PHARMACEUTICAL RISK PETER FELDSCHREIBER