Use of personalized cancer drugs runs ahead of the science

Asher Mullard in Nature:

TrialAs the costs of genetic sequencing fall, oncologists are starting to prescribe expensive new drugs that target the genetic profiles of their patients’ tumours, even when those treatments have not been approved for the particular cancer involved. But such 'off-label' use is running ahead of the state of scientific knowledge, suggests the first randomized clinical trial to test the idea. The study, published in Lancet Oncology, found that using personalized cancer drugs off-label provides no benefit over conventional chemotherapy1. “This study is important because many oncologists have already adopted the personalized approach,” says Daniel Catenacci, an oncologist at the University of Chicago, Illinois, who was not involved in the trial. “Why have they abandoned the science?” Lead author of the study Christophe Le Tourneau, an oncologist at the Curie Institute in Paris, says that he sees such off-label treatments “quite often” in practice. “I understand why it happens: patients want to live and physicians want to offer help,” he says. But Le Tourneau adds that patients whose tumours have genetic alterations that might be targeted by a non-approved drug are better served by entering clinical trials.

Precision treatments

A small but growing number of personalized cancer drugs have been approved for treating particular cancers that involve specific mutations, but oncologists hope that these drugs will also work against related mutations in other cancers. By some counts, more than 30% of cancer drugs are prescribed off-label2, 3. To test the benefits of off-label tailored drug regimens, researchers at eight French hospitals analysed their patients’ tumours to look for genetic or molecular abnormalities that might be amenable to precision medicine. The researchers randomly assigned 195 suitable patients either to one of 10 potentially relevant targeted treatment regimens, or to chemotherapy. There was no significant difference between the effects of the treatments.

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