Drug Lag and Associated Factors for Approved Drugs in Korea Compared with the United States

(1) Background: Drug lag, the delay between the first global regulatory approval and approval by the national health authorities in other countries, impacts the accessibility of drugs. Although the Korean pharmaceutical market has grown significantly, most of its innovative drugs for public health depend on imports from foreign pharmaceutical markets. (2) Methods: We extracted data from the official websites of the Korean Ministry of Food and Drug Safety (MFDS) and the US Food and Drug Administration. Information on new molecule entity drugs, approved as imported drugs by MFDS from 2000 to 2019, was extracted. Multivariate Cox proportional hazard models on drug approval were estimated. (3) Results: In total, 424 drugs were analyzed. Orphan drugs designated by MFDS were less likely to receive approval (HR = 0.731, 95% CI: 0.572–0.934). The drugs with Korean MAHs were less likely to obtain drug approval than those with MAHs of subsidiaries of multinational pharmaceutical companies (HR = 0.524, 95% CI: 0.371–0.738). In the analyses for non-orphan drugs (n = 37), oncology drugs that need local clinical study (HR = 0.247, 95% CI: 0.093–0.657) and drugs that need more patients in a local clinical study (HR = 0.993, 95% CI: 0.988–0.999) were less likely to receive approval, with longer drug lag. The higher number of clinical studies in Korea was associated with a shorter drug lag (HR = 2.133, 95% CI: 1.196–3.805). (4) Conclusions: Our findings imply that Korean pharmaceutical companies should augment their research capabilities for new drug development. Furthermore, consideration of orphan drugs used in rare diseases is needed for drug approval to ensure the availability of these drugs in the market without approval delays.