The speed of drug regulatory agencies in the United States and Europe is often a source of discussion. The objective of this research was to assess regulatory review duration of first and supplementary indications approved between 2011 and 2020 in the United States and Europe (European Union [EU] and Switzerland) and differences in submission times between the United States and Europe. Descriptive statistics were applied to review times between the jurisdictions and across the therapeutic areas. A regression analysis was done to estimate the association between approval agency and review times. The primary analysis cohort included 241 drugs approved in the United States, the EU, and Switzerland. Of these, 128 drugs had supplemental indications (331 in total) in the United States and 87 had supplemental indications (206 in total) in the EU. Overall median review duration from submission to approval subtracting the clock stop period was 39 weeks in the United States, 44 weeks in the EU, and 44 weeks in Switzerland. When review times within each drug were compared, the European Medicines Agency took a median of 3.7 weeks (IQR, -6.7 to 14.9 weeks) longer than the U.S. Food and Drug Administration and Swissmedic a median of 0.3 weeks (IQR, -10.6 to 15.3 weeks) longer. Median total review duration for supplemental indications was 26 weeks in the United States and 40 weeks in the EU. Applications were submitted a median of 1.3 and 17.9 weeks later in the EU and Switzerland, respectively, than in the United States. The regression analysis showed small differences in submission times between the United States and the EU (-2.1 weeks [95% CI, -11.7 to 7.6 weeks]) and larger differences between the United States and Switzerland (33.0 weeks [CI, 23.1 to 42.8 weeks]). It would be beneficial for patients if differences in submission times between the United States and Europe continue to be minimized.