Fig. 1.

a Time evolution of attrition rates at different stages of drug development. Black circles: data; red solid lines: linear regression in the corresponding time window; blue vertical solid line: changepoint. In a given year, the attrition rate for each development phase is defined as the percentage of projects that started the phase in that year and failed to pass to the subsequent phase within 4 years (accordingly, 2013 is the last year we do consider). b Average (± standard deviation) yearly phase-by-phase attrition rates in three different time intervals (1990–1999, 2000–2009, 2010–2013). We also report the significance level of a Wilcoxon rank sum test [25] on the difference of attrition rates in 2000–2009 and 2010–2013