Print“Biopharmaceutical companies have increasingly focused their oncology programs on the development of targeted drugs that attack a specific genetic or molecular drivers of cancer growth.”
Treating cancer with targeted therapies appears to be less toxic than traditional chemotherapy, according to a new analysis conducted by researchers at The Institute of Cancer Research, London, and The Royal Marsden NHS Foundation Trust. Researchers analyzed data from 36 early stage clinical trials run by the organizations' joint Drug Development Unit. Their findings, recently published in the Annals of Oncology, found the overall risk to patients suffering a life-threatening side-effect was about seven times less than for traditional cytotoxic agents.
Biopharmaceutical companies have increasingly focused their oncology programs on the development of targeted drugs that attack a specific genetic or molecular drivers of cancer growth, rather than chemotherapies that kill all rapidly dividing cells.
Early stage trials, when drugs are first tested in humans, are designed to evaluate a drug’s safety and determine the optimal dose. However, recent studies have shown that patient response rates in the first human trials of the new generation of targeted drugs are approximately two-fold higher than for non-targeted therapies.
Patients face many uncertainties during initial dosing in early-stage trials. But, until now, the risk of side effects for patients taking part in early stage trials of new targeted therapies has been unclear.
“The theory behind targeted drugs is that they should affect only cancer cells that have a specific fault and spare healthy cells, which we hoped would lead to higher rates of efficacy and lower rates of side-effects,” says senior study author Rhoda Molife, a medical oncologist and senior investigator in early stage clinical trials in the Drug Development Unit of The Institute of Cancer Research and The Royal Marsden. “It's very pleasing that our study seems to back this up, at least in the context of Phase I trials.”
Scientists retrospectively analyzed data from 687 patients treated at the Drug Development Unit of The Institute of Cancer Research and The Royal Marsden between January 2005 and December 2009. They had a range of cancer types, with gastrointestinal, gynecological, and sarcoma among the most common.
For targeted drugs, the most common toxicities were gastrointestinal—such as loss of appetite, diarrhea and vomiting—and fatigue, while side effects for cytotoxic drugs are generally hematological or cardiovascular in nature.
Patients were more likely to suffer side effects if they were given a higher dose than that which the trial later found to be optimal or if they were sicker when they joined the trial. The findings should help guide researchers in selecting patients for trials and improving trial design.
“The discovery of targeted therapies is revolutionizing the way we treat cancer, and is a key focus of our research here at The Institute of Cancer Research,” says Alan Ashworth, the Institute’s chief executive. “Many of these drugs have individually transformed the care of certain cancers, but the strength of this study is that it helps confirm the validity of the overall approach.”
The Drug Development Unit of The Institute of Cancer Research and The Royal Marsden is supported by the National Institute for Health Research Biomedical Research Centre for Cancer, and also receives funding from Cancer Research UK and the Experimental Cancer Medicine Centre network.
August 09, 2012
http://www.burrillreport.com/article-targeted_drugs_show_less_serious_side_effects_.html
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