Generic atorvastatin and rosuvastatin in the South Korean market: time of introduction in relation to manufacturer characteristics.

Background: The competition for and market dynamics of generic medicines can be understood by analyzing manufacturers' behavior. In this study, we analyzed the various types of generic atorvastatin and rosuvastatin that were introduced onto the South Korean market from 2002 to 2018 and their corresponding manufacturers.
Methods: Based on publicly available data, we selected drugs containing atorvastatin and rosuvastatin as active ingredients for the analysis. We calculated the time between the date of marketing approval for the first generic and that of the remaining generics. Then, we categorized manufacturers that marketed generics into first movers and latecomers.
Results: We confirmed that many manufacturers have marketed generic drugs in South Korea and that manufacturers can be categorized as first movers and latecomers. Interestingly, latecomers account for a large portion of the manufacturers of generics, and they have entered the market steadily, even after the market matured with a number of manufacturers. Additionally, the characteristics of the manufacturers were closely related to manufacturers' behaviors in the market. Conclusions: The order-of-entry effect, which is commonly observed in other markets, is marginal in the South Korean market, and this phenomenon is mainly explained by the rare price competition among generic manufacturers.