Recent studies have shown that patient response rates in phase 1 trials of new-generation targeted drugs are approximately 2-fold higher compared with previous trials. Yet, the risk of side effects to patients participating in early-stage trials of targeted drugs has been unknown.
Now, researchers from The Institute of Cancer Research (ICR), London, and The Royal Marsden (RM) NHS Foundation Trust report that patients in early clinical trials of targeted cancer therapies appear to have a much lower risk of the most serious side effects compared with traditional chemotherapy.
The study, published in Annals of Oncology, analyzed data from 687 patients and found the overall risk to patients of suffering a life-threatening side effect was around 7 times less than for traditional cytotoxic agents.
Senior author Dr Rhoda Molife, a medical oncologist and senior investigator in phase 1 clinical trials in the Drug Development Unit of ICR and RM, said: “Our study found that the risk of developing a serious side effect in a phase 1 trial of a targeted drug was relatively low, compared with previous analyses of similar trials of old-style chemotherapies."
“Importantly, we also identified characteristics that put patients at higher risk of these toxicities, including if they were sicker when joining the trial. This will help doctors make the right choices about who should be given new drugs in early stage clinical trials.”
Scientists retrospectively analyzed data from 36 phase 1 trials performed at the Drug Development Unit of ICR and RM between January 2005 and December 2009. The trials included various cancer types, with gastrointestinal, gynecological, and sarcoma being the most common.
The most common toxicities for targeted drugs were gastrointestinal, ie, loss of appetite, diarrhea and vomiting, and fatigue. Side effects for cytotoxic drugs are generally hematological or cardiovascular in nature.