Sundar R, et al. - Researchers report the outcome of the largest cohort of adolescent and young adult (AYA) patients with advanced solid tumors treated in phase I clinical trials. They analyzed clinical trial data of AYAs (defined as aged 15–39 years at diagnosis) treated at the Drug Development Unit, Royal Marsden Hospital, between 2002 and 2016. Gynecological cancer (25%) and sarcoma (18%) were major tumor types. Grade 3/4 toxicities were reported in 26% of patients. Benefit was observed in a subgroup of patients, with several durable responses beyond 2 years. Cancer syndromes, significant family history or somatic molecular aberrancies were reported in a sizeable proportion of AYA patients. The reported median overall survival (OS) was 7.5 months and 2-year OS was 11%.