Analysis Compares the Rates of Access of Adolescents and Young Adults to Clinical Trials of New Drugs

The 18 year old inclusion limit in clinical trials prevents adolescents from benefiting from novel drug treatment

Compared to young adults, adolescents with the same types of cancer have far less access to immunotherapy and/or targeted therapies, according to findings presented at the TAT 2019 – International Congress on Targeted Anticancer Therapies in Paris, France. In addition, young adults could be included in clinical trials of these novel drugs nearly three years earlier than adolescents.

Lead author Teresa de Rojas, Medical Department, EORTC - European Organisation for Research and Treatment of Cancer in Brussels, Belgium and colleagues conducted this study to determine the access of adolescents with cancer to targeted therapies and immunotherapies and to innovation, as measured in the number of mechanisms of action (MoA), compared to young adults. The investigators also aimed to describe the time lapse between the first adult trial for a specific drug and the first trial recruiting adolescents for that same drug.

Few clinical trials allow inclusion of adolescents compared to the number available to young adult patients with cancer

The team searched to identify all clinical trials initiated between January 2007 and July 2018 that included patients with malignancies that were relevant for adolescents and young adults (AYAs), such as Hodgkin lymphoma, anaplastic large cell lymphoma, extracranial germ cell tumours, medulloblastoma, rhabdomyosarcoma, synovial sarcoma, Ewing sarcoma, osteosarcoma, melanoma, and thyroid cancer. This analysis included only trials investigating immunotherapies and/or targeted therapies. The trials, drugs, and MoA were categorised as “available for adolescents”, which was defined as patients 12 to 18 years old, and “available for young adults”, defined as patients 18 to 25 years old.

Review of the database uncovered 2765 trials; of these 1369 trials investigating targeted therapies and/or immunotherapies were included in this analysis. A total of 1352 (99%) trials were uncovered that were available to young adults compared to just 233 (17%) that were available for adolescents.

Clinical trial inclusion was delayed for adolescents by almost three years

The analysis comprised 384 novel drugs that were either targeted therapies or immunotherapies that were investigated in clinical trials. Of these, all 384 drugs were available for the treatment of young adults through trial inclusion, whereas less than one-third (108 drugs; 28%) of these therapies were available for treatment of adolescents.

Of the 108 drugs investigated in adolescents for the designated malignancies, 59 were investigated first in adults, resulting in a median delay of 35 months (interquartile range [IQR] 23 to 60 months) until the drug trial was open to adolescents. No time trend in this delay was observed over the years of the study.

All of the 184 investigated MoA were accessible to young adults compared to only 61 (33%) MoA investigations allowed to adolescents.


Access to novel therapies according to age. There is a prominent gap in the access to innovative treatments. As seen in the figure, the access to trials investigating immunotherapies and/or targeted therapies is much more restricted for younger patients (<18 years). The 18-years-old inclusion limit constitutes a major barrier. © Teresa de Rojas.


There is a major gap in the access to novel drugs and innovation between adolescents and young adults, according to the investigators. The 18-year-old limit for inclusion in the majority of clinical trials poses a large barrier to the treatment of adolescents.

A prominent delay also exists between when trials are open to young adults and the opening of trials for adolescents, with no improvement observed over the last decade.

The authors recommend that greater effort be made to improve clinical research for AYAs with cancer. 


29O - de Rojas T, Neven A, Garcia-Abos M, et al. The 18-year-old clinical trial inclusion limit is a major barrier in the access to immunotherapies and targeted therapies for adolescents and young adults (AYAs) with cancer.

No external funding was reported for this trial.