Overview of the clinical trials in Bulgaria - phases and designs

Abstract

Introduction Each and every year a high number of new medicines are developed and introduced to the medical practice by the pharmaceutical industry. Part of the way from the research lab to the market is a row of consecutive clinical trials that costs an immense investment of labor force, time and money. From approximately 50000 new synthesized compounds just about 5 reach the phase of research on humans. And only one of them shows an acceptable level of safety and efficacy to obtain ethics and regulatory approval (market authorization is granted) and then reaches the stages of production and use. In addition, every drug is approved for a specific indication, for the treatment of a very specific condition or set of conditions. The development of every single medicine is the result of a close interaction between the pharmaceutical industry and lead laboratories and clinics, regulatory agencies, health authorities, etc. Materials and Methods The purpose of the review is to provide a high-level overview of the types clinical trials and their representation in Bulgaria. Documentary and database research are the main or the principal research method. Documentary research in social science is a useful and underutilized approach that can be adopted by researchers, it is also a scientific method that requires strict adherence to research protocol. Results Globally, there are 14282 ongoing studies (Aug 23, 2016), conducted by the industry. The distribution of phases of these ongoing studies is the following: phase 0 – 90, phase I – 3099, phase II – 3907, phase III – 2395, phase IV – 1478. Therefore, it could be noted that the global trend is that phase II trials are currently the most numerous. Also, the number of trials in phase I, II and III is close. In Bulgaria there are 223 cur-rently ongoing trials (Aug 23, 2016). 178 of those are randomized. 171 of the ongoing clinical trials in Bulgaria are randomized clinical trials with parallel design. Regarding the phases – of these 171 – 11 are phase VI, 108 are phase III, 47 are phase II, 5 are phase I. According to the data posted on ClinicalTrials.gov currently in Bulgaria there are only 2 ongoing studies with crossover design. One of them is randomized, phase I and Bulgaria is the only country, where it is conducted. In Bulgaria, there are only 2 ongoing clinical trials with factorial design. One of them is phase IV and the other one is phase III.