The concept of precision medicine for cancer generally involves finding specific mutations in a patient’s cancer, then targeting a therapy to treat that specific mutation effectively.
Precision medicine in cancer care leads us to transition from a “one size fits all” approach of categorizing cancers by the body organ where they began (eg, breast, lung, colon) to a focus instead on specific identified mutations that may drive a cancer. One advantage of the old model of treating broad populations with the same approach was that it was possible to conduct studies that included many patients who, we thought, shared the same disease. With the greater resolution of precision medicine looking for particular mutations, we now must split those populations into much smaller subgroups. In some cases, these subgroups may be just a very small percentage of the overall population of patients with a given cancer, creating challenges in how to study the best treatments for them.
Two new and very different trial designs for molecular targets in cancer care are umbrella trials and basket trials.
An umbrella trial enrolls patients who share the same basic cancer type, performs molecular marker testing for a wide array of potential targets, then assigns patients to an arm of the study based on the presence of a mutation matched to a potentially effective treatment for that marker. In some cases, there is a “default arm” of a strategy with potentially broad activity for patients without a specific marker being evaluated. Different arms may open and close quickly on trials that can be modified over time as new targets and treatments become identified. This makes it possible to test and develop many potentially active drugs simultaneously.
A basket trial enrolls patients who have the same genetic mutation, whether their cancer originated in the lung, breast, colon, liver, or any other organ, then has patients all receive the same novel treatment that targets that specific marker. This strategy highlights a different way of thinking about cancers, not based primarily on where they originated but rather based on the mutation(s) that drive them.
If available at many cancer centers, umbrella and basket trials for molecular targets offer several major benefits for developing new treatment approaches:
It is possible to identify options for small subgroups, perhaps even with a marker seen in only 1% or 2% of a broad cancer patient population.
Patients and oncologists have an “actionable result” to suggest a plan of action when genetic testing panels report a rare mutation.
Patients from many locations can participate in trials for their specific target without needing to travel to distant sites.
New treatments can be tested and potentially approved for commercial use faster.
Cancer Ouija boards, umbrellas, and baskets: the evolution of genomic oncologyhttp://cancergrace.org/cancer-101/2014/11/02/cancer-ouija-boards-umbrellas-and-baskets-the-evolution-of-genomic-oncology/
What can we learn from genomically driven trials in other tumors?http://www.fda.gov/downloads/Drugs/NewsEvents/UCM423361.pdf
Published Online: December 8, 2016. doi:10.1001/jamaoncol.2016.5299
Conflict of Interest Disclosures: None reported.
West H(. Novel Precision Medicine Trial DesignsUmbrellas and Baskets. JAMA Oncol. 2017;3(3):423. doi:10.1001/jamaoncol.2016.5299