This study aims to investigate how much the market performance of drug therapies is influenced by their scientific evidence and price level. Compared to the seemingly simple objective, performing the analysis in the pharmaceutical industry makes the evaluation very complex. Examining the purchase decision process in the prescription drug market, besides the patient as the final consumer, the prescribing physician has the largest decision potential. In addition, the authors cannot ignore the healthcare system financing the therapy either, not to mention the interlacements of regulations, manufacturer interests, their marketing potential and marketing activities. This complexity makes it impossible to describe the pharmaceutical industry in uniform terms. The literature search also confirms that the mentioned complexity makes it hard to draw unambiguous conclusions. In spite of that –with a positivistic approach- the authors live with the assumption that scientific evidence (better efficacy and safety profile) should be awarded on the market on the aggregate level. It is inevitable to clarify at the very beginning that the authors investigate active pharmaceutical ingredients (APIs) and not brands in the recent study. With all this in mind, their intention is to introduce a novel approach for the evaluation of the relationship between the product characteristics (clinical evidence of APIs) and their market performance. In order to examine the relationship the authors involved APIs that belong to the same indication group, having the same mechanism of action and which have been in the generic competition for years after their patent have expired. As a model they perform the analysis with antihypertensive drug therapies. The authors consider that it is possible to rank the active ingredients of drug therapies on the basis of their efficacy and safety, based on relevant clinical literature. The result of ranking serves as the starting point of the analysis. Unequivocally, the authors do not forget about the additional factors that significantly influence the market performance of APIs, but deliberately do not involve these factors in the recent analysis. These factors are the different reimbursement and funding policies, marketing activity of the manufacturers, country-of-origin effect, the impact of clinical guidelines and clinical literature, and their effect on each other. There is one exception, since the article partially deals with the influence of price level on the market performance. In contrast with the majority of the available literature, this study aims to explore the identifiable patterns by investigating the European pharmaceutical market on system-level.