The search for surrogate endpoints for immunotherapy trials

Mushti and colleagues from the Food and Drug Administration (FDA) have used patient-level data from 13 trials comparing immunotherapeutic agents with standard treatment in various cancer types in an attempt to validate objective response (OR) and progression-free survival (PFS) as surrogate endpoints for overall survival (OS) (1). This is an important issue, given the current and future role of immunotherapy in several cancer types.