Clinical trials, also known as research studies, compare a new or different type of treatment with the best treatment currently available (if there is one). They may also look at possible ways to prevent illnesses, for example by testing new vaccines. Before a medicine can be licensed as safe, effective and of good quality it must go through clinical trials before its benefits and risks can really be known.
Trials aim to find out if treatments used in health care:
• Are safe
• Have side effects
• Work better than the treatment used currently
• Help people feel better
To determine these factors, clinical trials are conducted in phases each phase having a different purpose, helping scientists answer different questions:
Phase I trials, test an experimental drug or treatment in a small group of people (20-80) for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
In Phase II trials, the experimental study drug or treatment is given to a larger group of people (100-300) to see if it is effective and to further evaluate its safety.
In Phase III trials, the experimental study drug or treatment is given to large groups of people (1,000-3,000) to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the experimental drug or treatment to be used safely.
In Phase IV trials, post marketing studies delineate additional information including the drug's risks, benefits, and optimal use.
Clinical trials are needed to improve treatment and care for patients now and in the future. Many of the treatments now commonly used in the NHS have been tested through clinical trials. For example, in cancer care, trials have been used to try out new treatments – radiotherapy, chemotherapy, surgery and complementary therapies. Trials have also been used to find out the best ways of using these treatments. This means that many people with illnesses such as cancer and HIV/AIDS have been able to live longer and have a better quality of life.
Key messages
• Pfizer is committed to improving both the transparency and accessibility of clinical trial information. Over the past three years, we have worked closely with many key stakeholders to establish common international standards and databases for the registration of clinical trials and the disclosure of clinical trial results.
• Pfizer has had a policy of making clinical trial data available, and recently adopted the industry-wide approach of publishing our study results on the PHARMA website www.clinicalstudyresults.org, an industry-sponsored database for disclosing summaries of clinical trial results via a common database and in a common format.
• Pfizer has always disclosed the detailed results of all of its clinical trials to the FDA and other regulatory authorities around the world. These regulatory authorities carefully balance the risks and benefits of each medication, and reflect all important safety and efficacy information in the approved product labelling. Pfizer is governed by strict codes of ethics and conduct. The pharmaceutical industry is one of the most regulated industries in the world.
• No matter where they take place, Pfizer clinical trials are conducted in accordance with recognised international standards, as well as local laws and regulations. A qualified Independent Ethics Committee or Institutional Review Board reviews each trial protocol prior to it commencing, and independent drug safety monitoring boards are appointed to continuously monitor the safety of individual patients within a trial. When Pfizer clinicians design a clinical study, the safety of patients is always their paramount concern.