Influence of Drug Lag on New Drug Label Revisions

Drug lag (DL) in Japan has decreased in the last few years as a result of the globalization of drug development in the past decade, and new molecule entities (NMEs) with short DL are on the rise. The purpose of this study was to investigate the influence of DL on postmarketing safety of NMEs, by comparing the length of DL and the chronological trend of package insert revisions. The number of label revisions occurring during 6 years after approval was investigated for 142 NMEs approved between 2000 and 2006. The NMEs were classified by the length of DL (2 years and 4 years), and the label revision trends by each label section and therapeutic categories were analyzed. The cumulative number of level revisions in the “Drug Interactions” and “Clinically Significant Adverse Reactions” sections in the first year after approval in the DL <2 years group was significantly greater than in the DL ≥2 years group. In the chemotherapeutic category that showed the shortest DL, the first label revision occurred in 33.3% within the first year and in 66.7% by the second year, and label revisions were performed earlier than in any other therapeutic categories. These results suggest that the package inserts of NMEs with a shorter DL tend to be revised earlier and more frequently, and it requires more careful monitoring of safety information after product launch