Our study suggests that therapeutic area as well as number and types of clinical procedures involved are the key drivers of costs in Phase 1 through Phase 4 studies. The therapeutic areas with the highest per-study costs in Phase 1 is immunomodulation ($6.6 million), in Phase 2 is hematology ($19.6 million), in Phase 3 is pain and anesthesia ($52.9 million), and in Phase 4 is respiratory system ($72.9 million). Figure 5 presents an overview of the different types of costs constituting each phase and their magnitudes. The denoted error bars represent one standard deviation below and above the mean value.
Figure 5: Per-study Costs across All Therapeutic Areas, by Cost Component and Phase
Excluding site overhead costs and costs for sponsors to monitor the study, the top cost drivers of clinical trial expenditures across all study phases are Clinical Procedure (15 to 22 percent), Administrative Staff (11 to 29 percent), Site Monitoring (nine to 14 percent), Site Retention (nine to 16 percent), and Central Laboratory (four to 12 percent) costs (see Table 2 above).