The popular narrative surrounding cancer drugs or other therapies for rare diseases is that patients are willing to assume more risk and uncertainty to gain rapid access to investigational agents. This is, in part, the impetus behind the frequent use of surrogate endpoints by the US Food and Drug Administration (FDA)1 and European Medicines Agency,2 as well as the right-to-try legislation.3 This US law permits patients with terminally ill conditions to receive experimental therapies without the approval of the FDA.