Content - Trial conduct

Development, procedure and evaluation


On the basis of a given observation, academic researchers or scientists who work for pharmaceutical companies present a hypothesis, which is then investigated in a study. The objectives of a clinical study must be carefully defined in the study protocol, i.e. the study plan. The protocol summarizes study results to date and precisely describes the objectives of the new study. It also defines the number, time and scope of the tests, as well as the nature, time, duration and level of dosing with the active substance. The inclusion and exclusion criteria for participation in the study are listed in the protocol, which also states the number of patients needed for reliable conclusions to be drawn on the basis of statistically relevant study results. The study must have sufficient participants in order for the sought-after improvement to be actually observed with sufficient certainty. The researchers apply for permission to carry out the study from the authorities and ethics committees.



On the basis of the protocol approved by the authorities, the efficacy and safety of the new treatment is then investigated in patients at hospitals and in private practices. In randomized Phase II and Phase III studies, the participating patients are assigned in a randomization process to groups, so-called study arms, which are treated according to different treatment plans. In these studies, the efficacy of a new treatment is studied in comparison with that of standard therapy. To prevent the results from being influenced by the expectations of patients and doctors, it is occasionally necessary to carry out a study double-blind, i.e. neither the patient nor the doctor knows who is receiving which treatment. The patients are treated and tested according to the requirements defined in the protocol.



At the end of the study, statisticians analyse the values obtained in order to answer the question as to whether a treatment is effective and safe or which of several treatments is now also really measurably better. The results are also regularly monitored during the study. If one of the treatment methods shows excessive side effects or a lack of efficacy, the study is immediately stopped. If it already emerges during the course of the study that a treatment is clearly better, the study is likewise stopped and this treatment method made available to all patients. This is monitored by the study management and the regulatory authorities. Study results are published in scientific journals. Before this, the study design, analysis and conclusions are assessed and critically reviewed by other experts in the research field concerned. Only when their questions and suggestions for improvement have been taken into account to the satisfaction of the experts and scientific editorial board of the journal, can publication go ahead. This peer review is a process aimed at the quality assurance of scientific work by independent experts.