Editor’s Note: All this week Check Up will be sharing one new Pharma fact a day that was an important breakthrough in the world of pharmaceuticals in 2012. Today, Check Up delves into Pharma’s approach to cancer therapy.
For a decade or more pharma's researchers have believed that the most effective, least toxic way of treating cancer and, in all likelihood, most other diseases, lies in developing so-called targeted therapies that are based on the genotype of each patient. In many quarters this approach represents the basis of the so-called "personalized medicine."
The idea is that genotypes determine a disease's pathway in any given patient. Knowledge of the pathway in a individual will enable physicians to select the therapy to produce the best result and the smallest side effect for each patient.
The general idea is certainly captivating. Nowhere have scientists and physicians gone as far with it as in cancer. Now a study published this month in Science by researchers from the University of Toronto suggests that developing a targeted therapy based on a tumor's genome is not likely to be effective because tumors with identical genomes often behave very differently.
Comparing several tumors with identical genomes, Antonija Kreso, Catherine O'Brien and their colleagues found that some will spread quickly while others barely metastasize at all. Some tumors will wither after exposure to a cytotoxic drug, even as others remain unfazed by it.
Molecular geneticist John Dick of the Princess Margaret Cancer Centre in Toronto, another author of the study, suggested that defeating cancer will require drugs that also target the non-genetic properties of tumors. Presently very few researchers, in or out of pharma, are doing that.
As a result it may be at least decade or two before a raft of breakthrough drugs appear in cancer, auto-immune diseases and several more categories.
- Dan Hoffman