More than 40 years after President Nixon declared “war on cancer,” it remains a death sentence for most patients, with mounting economic and regulatory pressures that challenge traditional approaches to drug development. The emergence of drugs that target a patient’s specific genetic profile could revolutionize cancer treatment, affecting how patients are treated, how effective the treatments are, and how quickly they move from the clinic to market.
Historically, cancer research has focused on finding treatments that work for a broad group of patients. These approaches yield little success: they require extensive clinical testing before approval and deliver, on average, only incremental improvement in how a patient is likely to fare. Our industry has been plagued by an unacceptable rate of clinical failures and a shortage of breakthrough drugs for patients. It is my belief that the primary reason for this failure is the inability to define a narrow group of patients who are most likely to respond to a new drug, based on their genetic profile or other specific biological characteristic.
The emerging field of “precision medicine” or “personalized medicine” features new therapies that target, for example, a specific genetic mutation in the tumors of a small set of patients. These new approaches can be more effective than traditional methods, and are generally expected to be eligible for quicker review processes from the US regulator, the Federal Drug Administration, aimed to help breakthrough products get to patients faster.
One prominent example of the promise that personalized medicine offers is the US FDA approval of Xalkori, developed by Pfizer, which treats patients of a specific genetic profile who have a normally fatal form of lung cancer (late-stage, non-small cell lung cancer, or NSCLC). Approximately one to seven percent of those with NSCLC have an “ALK gene abnormality” which causes cancer to develop and grow. In 2011, one study presented at the American Society of Clinical Oncology meeting revealed that 60 percent of patients on Xalkori were alive after two years, compared to nine percent in historical controls.
In effect, some cancer cells become “addicted” to a specific metabolic enzyme. If you could take a pill that blocks that enzyme, then the cancer cells would not be able to metabolize the nutrients they need to survive, while normal cells would be spared.
The next step is to identify the patients whose cancer depends on that enzyme, based on their genetic and metabolic profile. We believe there could be 50 to 100 metabolic enzymes on which various cancers depend for their survival, from which a new wave of cancer therapies could emerge.
The advances made by these discoveries and drugs are just glimpses into the promise and potential of precision medicine. Cancer and other diseases will no longer be comprised of a few common diagnoses, but will instead grow into a list of specific genetic mutations that can be targeted with its own drug regimen.
As a treating physician and a member of the biotech industry, I look forward to seeing new treatments emerge that will offer hope for cancer patients and help us to gain ground in the war on cancer.
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Author: Dr David Schenkein is CEO of Agios Pharmaceuticals, a 2014 Technology Pioneer company.
Image: A tray containing cancer cells sits on an optical microscope in the Nanomedicine Lab at UCL’s School of Pharmacy in London May 2, 2013. REUTERS/Suzanne Plunkett