Fig. 4

Share of rare indications, number of mechanisms of action, and novelty of indications and mechanisms of action. a Evolution in time of the share of projects targeting rare diseases (i.e. having a prevalence of fewer than 200,000 affected individuals in the US) and of the average number of mechanisms of action per project, between 1990 and 2017, by project starting year (i.e. the year the focal project entered preclinical research). b Evolution in time of median novelty of indication/mechanism of action per project, between 2000 and 2017, by project starting year