years is the average length for the clinical trial research phase.
Source: Chi-Jen Lee, Clinical Trials of Drugs and Biopharmaceuticals
of clinical trials do not manage to recruit and retain enough patients and fail to meet enrollment timelines.
Source: Clinical trial delays: America’s patient recruitment dilemma
is the total cost of developing one new drug and making it through the FDA approval phase.
Source: Duggan & Pence, Approval Rate for Drugs Entering Clinical Development, 2019