Biovigilance and pharmacovigilance for haemophilia

Christopher Ludlam Drug therapy aims to maximize therapeutic efficacy and minimize the risk of harm. Treatment is monitored by patient and physician after its initiation. For individuals with life-long conditions, it is important that the cumulative adverse risks of frequently repeated treatment do not exceed the benefits of long-term therapy. The short-term benefits of therapy may be self evident, whereas the potential accumulation of adverse events may take a long time to become manifest. The time to quantify adverse events may be reduced by surveying and monitoring large numbers of patients, often many thousands of individuals, simultaneously. To do this for a rare disorder such as haemophilia requires extensive, often international, collaboration between haemophilia centres serving patients often living in very different social and environmental conditions. To collect and interpret, these data pose considerable challenges. For most successful surveillance, it is necessary to identify, in advance, potential adverse events which can be ‘logged’, e.g. inhibitor development in haemophilia, but this may overlook new unexpected events, e.g. new infectious agent. The latter has been especially challenging in haemophilia therapy because most of the blood-borne infections are clinically ‘silent’ for prolonged periods. It is therefore especially important to have effective monitoring of potentially infectious agents in the blood-donor community, so that infectious donations do not contribute to the plasma pool from which the clotting factor concentrate is manufactured. In addition to surveillance for expected adverse events, it is also desirable to have some form of ‘open-ended’ monitoring for other events. This is sometimes complicated by it being unclear whether the event is part of the underlying disease process, an alternative medical disorder or a side effect of therapy. One way to collect open-ended data is by recording causes of death. To analyse these, it is often necessary to relate the causes to what is found in the local general population. This can be challenging when the surveyed patients live in different communities in different geographical areas. The challenge, therefore, is to arrange the collection of data that can be interpreted in a way that can be useful in guiding future therapy and managing the underlying medical condition. Some of the current schemes for haemophilia are outlined below. Ideas for improving surveillance, especially using information that is already being collected possibly for other purposes, are also considered. Mark Weinstein The US Advisory Committee on Blood Safety and Availability has defined ‘biovigilance’ as a comprehensive and integrated national patient safety programme to collect, analyse and report the outcomes of collection and transfusion and/or transplantation of blood components and derivatives, cells, tissues and organs [1]. Here, we are using the term pharmacovigilance to apply to plasma dirivatives and their recombinant analogues. To the haemophilia and rare bleeding disorders community, the need for blood product phamacovigilance, and biovigilance which includes haemovigilance is self evident, given the challenges to patient and donor safety we have experienced over the past 30 years. These include problems with donor screening and testing; blood product manufacture; adverse events associated with product administration and receipt and threats of counterfeiting and terrorism. The major focus of haemovigilance programmes in the United States and other countries is to assure the safety and supply of transfusible blood components, including whole blood, platelets, red blood cells and plasma. These products are not pathogen inactivated in the United States, are widely used, have inherent biological variability and are susceptible to shortages based on donor availability. This is not to say that pharmacovigilance with regard to plasma derivatives and recombinant analogues is neglected in any way, but that the expanding scope of haemovigilance activities directed toward blood components is greater, given their wide use and potential to transmit injections diseases. Pharmacovigilance and biovigilance are needed to identify whether an emerging infectious agent is transmissible by a blood product. Examples of biovigilance in this area include identifying and understanding the nature and epidemiology of HIV, West Nile Virus and variant CJD. Through epidemiological studies and before specific tests are developed, biovigilance can help establish donor eligibility and deferral criteria, based on identifying potential sources of pathogen exposure. Once tests are developed to detect the agent, biovigilance can identify how many donors, patients and products are actually exposed to the pathogen, and whether current manufacturing procedures mitigate infectious disease risk. Pharmacovigilance is needed to identify blood derivative products that are contaminated with pathogens or foreign material through failures in product manufacturing or through deliberate acts of counterfeiting or terrorism. For example, biovigilance identified a failure in good manufacturing practices, where patients developed sepsis through receipt of albumin contaminated with bacteria because of cracks in the product vial [2]. Deliberate acts of sabotage include adulteration of immune globulin [3] and heparin [4]. Biovigilance can reveal whether the manufacturing process for a given product is capable of clearing a known or emerging pathogen. As one example of phamacovigilance in this category, examination of adverse event data and reports from a patient organization showed that patients acquired hepatitis A from one brand of factor IX. This led to manufacturing changes in the product that reduced the potential of hepatitis A transmission [5]. Pharmacovigilance can be used to identify products that have an intrinsic defect or cause an unexpected number of adverse events that are unrelated to pathogen contamination or manufacturing deviations. For example, on rare occasions, patients receiving a lot of immune globulin have experienced more than the expected rate of allergic reactions to the product for unknown reasons. Mark Weinstein To address these challenges, pharmacovigilance and biovigilance programmes should provide mechanisms for surveillance, sentinel identification, traceability, exchange of information among stakeholders and analysis and interpretation of data. Biovigilance has many different aspects that involve a variety of data collection methods, analysis and resolution. In the United States, biovigilance programmes are only now becoming centralized. Coordinated safety and public health efforts are shared by various divisions of Health and Human Services agencies including the Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), the National Institutes of Health (NIH) and Centers for Medicare and Medicaid Services (CMS), with input from trade, academic, industrial and patient groups. In the US, the CDC has the primary responsibility for conducting national disease surveillance and developing epidemiological and laboratory tools to enhance surveillance. CDC’s emerging infectious disease working group gathers information from multiple sources, including state health surveillance, literature reports and reports from regulatory authorities worldwide. CDC shares information about pathogens that might affect blood products with relevant offices within the FDA, and other governmental agencies as appropriate, such as the Department of Defense. FDA assesses the risk of potential pathogen transmission by blood products and develops a risk mitigation strategy depending on the nature of the pathogen. The Centers for Disease Control and Prevention’s National Healthcare Safety Network (NHSN) has worked with the AABB (formerly the American Association of Blood Banks), a trade organization, to develop a web-based haemovigilance system that collects data from hospitals to detect adverse transfusion events such as reactions to blood products, process problems and medical errors. The information, collected using standardized data collection tools, can be used to create benchmarks for trending purposes, provide opportunities for data-driven intervention, including validation, quality control and impact measurement. The first module of this programme, that became operational in February, 2010, is designed to collect information about recipients of blood product transfusions; a second module on blood donors will be implemented shortly. Other CDC surveillance programmes include the Universal Data Collection project to monitor the safety of the nation’s blood supply for persons with bleeding disorders being treated with blood products, as well as to monitor the occurrence of joint complications experienced by persons with haemophilia. CDC also has a programme to monitor for any emergence of Creutzfeldt–Jakob disease. The Food and Drug Administration has a number of different surveillance programmes for blood products that vary according to the type of product under scrutiny, e.g. blood components such as whole blood, cells or plasma, or manufactured products such as plasma derivatives. The Food and Drug Administration leads biovigilance related to blood fatality surveillance for transfusions and donations. A blood collecting or transfusing facility must notify the FDA’s Center for Biologics Evaluation and Research’s (CBER) Office of Compliance and Biologics Quality (OCBQ) when a blood donor or recipient dies, and the death is possibly related to the donation or transfusion. Besides fatality reports, OCBQ receives biological product deviation reports on distributed biological products about any event associated with the manufacturing of blood, blood components or plasma derivatives that deviates from current good manufacturing practices, regulations, standards or specifications that may affect the safety, purity or potency of the product. OCBQ also receives reports about unexpected or unforeseeable events that may affect the safety, purity or potency of these products. Summary results are available at http://www.fda.gov/BiologicsBloodVaccines/SafetyAvailability/ReportaProblem/BiologicalProductDeviations The Food and Drug Administration’s postmarketing safety surveillance programme for all approved drug and biological drug products (except blood and blood components) is supported by the Adverse Event Reporting System (AERS), a computerized information database. The FDA receives adverse drug event reports from manufacturers as required by regulation. Additionally, health care professionals and consumers send reports voluntarily through the MedWatch programme. Although MedWatch and AERS are the formal information systems for submitting suspected side effect reports to FDA, such information occasionally comes to light through other channels. Examples include direct informal consumer or health care professional contact with FDA’s Office of Communication, Outreach and Development (OCOD) or clinical trial data received by the Office of Blood Research and Review. The Food and Drug Administration also collects information from large data sources such as CMS claims data, the Department of Defense and the Veterans Administration among others. FDA’s Sentinel Initiative that is currently under development will strengthen FDA’s ability to monitor postmarket product performance by expanding our access to existing automated healthcare data. Information from large data sources is used for biological product safety hypothesis testing and surveillance within defined populations. One example of the use of survey information from large databases might be examining CMS claims data for the occurrence of Transfusion Related Acute Lung Injury (TRALI) among US elderly inpatients. Non-governmental organizations such as AABB, the Plasma Protein Therapeutics Association and the American Thrombosis and Hemostasis Network also have a role in monitoring and reporting adverse events. Efforts are now underway to expand our surveillance capability and increase cooperation amongst stakeholders. In Canada, the Transfusion Transmitted Injuries Surveillance System (TTISS) of the Public Health Agency of Canada (PHAC) collects haemovigilance data. Hospitals report adverse incidents to provincial/territorial blood offices on standard forms, using standard definitions. The local offices report a subset of data to the PHAC that excludes minor incidents and incorrect blood component transfusion information. The PHAC also receives voluntary and mandatory reporting information, including deaths and severe reactions from plasma and blood manufacturers. The PHAC validates the data, assuring completeness and accuracy and compliance with standard definitions. An analysis of the data is reported annually. It includes information about adverse transfusion events by type of product, number of blood components transfused, diagnosis of adverse transfusion events by type of blood component or plasma derivative and fatalities. Mike Makris The demonstration of safety of the treatments relies on pharmacovigilance, a term used to describe surveillance, monitoring and investigation of adverse drug reactions. The two main aspects of pharmacovigilance are: Voluntary reporting by health professionals (and patients) to regulatory authorities. This ideal is not however often followed, and some of the reasons for this failure are outlined in Table 1. Without an established process, voluntary reporting of adverse events in haemophilia has so far not worked well. Currently available reporting schemes such as Serious Hazards of Transfusion (SHOT) and Serious Adverse Blood Reactions and Events (SABRE) record only events in relation to unfractionated plasma products and specifically exclude clotting factor concentrates. Mandatory reporting from manufacturers. Formal studies evaluating new concentrates in terms of efficacy and safety required to obtain marketing authorisation involve small numbers of patients followed for a short period of time. The usage of these concentrates in real-life situations involves large numbers of patients of different ethnic and genetic backgrounds using the products over many years. Postmarketing surveillance studies are required to document frequent as well as rare adverse effects that may escape or fail to reach statistical significance in small cohort studies. Most postmarketing pharmacovigilance studies in haemophilia initiated by manufacturers have also been small, rarely recruiting more than a hundred patients. In Europe, the Paediatric Network for Haemophilia Management (PEDNET) is a group of 23 European paediatricians who since 2000 are enrolling all their new patients with haemophilia and following them prospectively for the development of inhibitors. The number of patients enrolled, however (250) is relatively small [6]. The primary aim of this group is to identify the incidence of inhibitors in untreated patients and investigate the role of factors in their development. While this is the most intensively studied group of patients, the number involved is relatively small. The only sizeable surveillance project in Europe currently is the UK Haemophilia Centre Doctors Organisation (UKHCDO) national database that only covers the UK. For the last 20 years, there has been a paper-based surveillance system for regular reporting of inhibitors, thromboses and infections. The only analysis performed and reported on from this surveillance system concerned the development of inhibitors [7]. The problem with this national system is that the introduction of national contracting has meant that all patients will be exposed to only a very limited number of concentrates and the value of the surveillance will thus be limited. The only other European country with a central AERS is the Netherlands, but no data from this system have been formally reported. No central haemophilia AERS is available in the other European Countries. Recently, a European AERS called European Haemophilia Surveillance System (EUHASS) has been initiated. European Haemophilia Surveillance System is a prospective adverse and serious event reporting system. A total of 56 haemophilia centres caring for 18 000 patients with inherited bleeding disorders in 27 European countries are taking part. The system is electronic, in English, and events are reported live as they occur or 3 monthly at the latest. The reported events are allergic/acute reactions, transfusion transmitted infections, inhibitors, thromboses, malignancies and deaths. As centres report data on the exposed population, incident rates can be calculated. In the first year of surveillance, 167 events have been reported. A total of 56 different clotting factor concentrates were used in the participating centres. EUHASS has the potential to provide pharmacovigilance information on large numbers of exposed persons with inherited bleeding disorders. As this is a dynamic cohort, a new method has been developed to calculate the inhibitor risk in patients with <50 exposures. Further information on EUHASS can be found at the project website http://www.euhass.org. Mark Weinstein The World Health Organization (WHO) is interested in developing a global haemovigilance network. In December 2007, the WHO Global Collaboration for Blood Safety (GCBS) met and agreed on the need to support such a network. A global consortium consisting of WHO, Canada, International Society of Blood Transfusion, European Haemovigilance Network and the USPHS agreed to form a multilateral steering committee to support collaborative efforts and develop a work plan. The Global Steering Committee for Haemovigilance (GloSCH) will: ‘provide an ongoing, international forum to develop and promote global haemovigilance; function as a forum for dialogue, advice and information gathering; promote standardized global haemovigilance reporting tools and determine whether these tools are useful and relevant; and share information concerning haemovigilance data among member organizations.’ The GloSCH is currently working on two documents: ‘Development of WHO Recommendations on Establishment of National Haemovigilance Systems’; and a technical and/or guidance document to support standardization of haemovigilance reporting. The EUHASS project has received funding from the European Union, in the framework of the Public Health Programme. Dr. Peter Gancz, Director, Centre for Biologics Evaluation, Biologics and Genetic Therapies, Health Canada, has kindly provided information about the haemovigilance in Canada, and the work of GCBS. For M. Weinstein, the findings and conclusions in this presentation have not been formally disseminated by the Food and Drug Administration and should not be construed to represent any Agency determination or policy.

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