Medicines play an important role in public health, bringing enormous benefits to patients in the fight against disease, but the use of medicines is not without inherent risk and no drug is completely safe. Ideally, a medicine would target only the disease that it is meant to treat and would not have any other effect. In reality, however, despite the best efforts of scientists, such a medicine does not yet exist and all medicines have possible side effects that some patients might experience. The safety of a medicine must therefore be described and evaluated in terms of the benefits it offers in the treatment of disease relative to the potential risk of unwanted side effects (the “benefit/risk profile”.) The benefits of a medicine must be weighed against its side effects and the acceptable level of risk decided upon by the company developing the therapy, by the regulators who approve it for marketing and ultimately by healthcare professionals, in consultation with their patients. The level of risk that is considered acceptable will depend, among other things, on the type of disease being treated – for example, in treating life-threatening diseases such as cancer, potentially serious side effects may be judged acceptable because of the desired beneficial effect of the medicine in saving or extending life. It also depends on an individual patient’s ability to tolerate a particular medicine and to comply with a treatment regime. The risks associated with alternative treatments, or no treatment at all, are also important considerations.
We aim to minimise the risks and maximise the benefits of each of our medicines - starting with our discovery of a potential new medicine and continuing throughout the medicine’s lifecycle.
In discovery research, thousands of compounds are investigated for their potential to become a new medicine. Only a small number succeed because of the demanding criteria of the ongoing selection process, which centres on safety and how well the medicine works. We aim to eliminate candidate medicines with potentially unacceptable benefit/risk profiles as early as possible. In pre-clinical development, regulatory authorities around the world require safety data from animal studies before permission is granted to begin testing a potential new medicine in humans (clinical development). Drug safety is a core focus of all our clinical trials and clinical safety data are collected and continuously evaluated throughout clinical development. In addition to our own internal resources, for some studies we also use independent external safety data monitoring boards to strengthen further the safety evaluation process. Once we have satisfied ourselves that a new medicine has an acceptable benefit/risk profile, we submit comprehensive information, including clinical trial data, to the regulatory authorities responsible for approving medicines in each country. Approval for marketing will only be granted if, after rigorous review of our submissions, the authorities decide that a medicine’s benefits in treating a particular disease outweigh its risks. After launch, we actively monitor the use of all our medicines to ensure that we become aware of any side effects not identified during the development process. Clinical trials, although extensive, cannot replicate the complete range of patient circumstances that exist among much larger and more diverse patient populations. Rare side effects can often only be identified after a medicine has been launched and used in far greater numbers of patients and over longer periods of time. We have comprehensive and rigorous systems in place for detecting and rapidly evaluating such effects, including mechanisms for highlighting those that require immediate attention. We also strive to identify whether particular types of patients may be more susceptible to the risks associated with a particular treatment, and what the early indicators of this might be, so that side effects can be avoided or minimised in these patients.
Information regarding possible side effects comes into AstraZeneca through a number of different sources, including healthcare professionals, patients, medical journals, our own ongoing clinical trials, and from regulatory agencies, who also monitor the use of medicines on the market. Whilst we make comprehensive efforts to collect all available information, not all side effects that occur are necessarily reported to us – for example, those that are not easily linked to the treatment. We have a dedicated global clinical drug safety database, which is designed to gather this information centrally for those responsible for drug safety across the organisation, at all levels, and for regulatory agencies. As well as the formal routine and ad-hoc safety review and evaluation process, our monitoring systems include mechanisms for highlighting those events that require immediate attention. If information received suggests that there is a change to a medicine’s benefit/risk profile, actions taken (alongside appropriate discussions with regulatory agencies) can include carrying out further clinical trials, modifying the prescribing information, and communicating with healthcare professionals and others who need to know of the change. In certain situations, it may be appropriate to stop an ongoing clinical trial or withdraw a product from the market.
We have an experienced, in-house team of over 500 clinical drug safety professionals working across AstraZeneca and dedicated to the task of ensuring that we meet our commitment to drug safety throughout the processes described above. Each of our products (whether in development or on the market) has an assigned global drug safety physician who, supported by a team of drug safety scientists, is responsible for that product’s continuous safety surveillance. Drug safety managers in each of our national companies have local responsibility for product safety within their respective countries.
Our Chief Medical Officer has overall accountability for the benefit/risk profiles of the products we have in development and those on the market. He provides medical oversight and ensures that appropriate risk assessment processes are in place to enable informed decisions to be made about safety as quickly as possible. His responsibilities include chairing a group of internal experts from both our Discovery and Development organisations, who critically evaluate our candidate drugs prior to first-time-in-man studies.
As part of the approval process, we work with regulators to develop prescribing information that provides healthcare professionals with the benefit/risk information they need to make prescribing decisions, including indications for use, dosing recommendations, warnings and contra-indications, and what side effects might be experienced. We also make information available to patients, as appropriate, about our medicines and how they should be taken.
We continue to provide information about the safe and effective use of each of our medicines to support appropriate prescribing decisions throughout a product’s life.
The content of this page was externally assured by Bureau Veritas, February 2008 |