The Whole Idea of a Clinical Trial is Inconsistent with Personalized Medicine
…even after some 400 completed clinical trials in various cancers, it’s not clear why Avastin works (or doesn’t work) in any single patient. “Despite looking at hundreds of potential predictive biomarkers, we do not currently have a way to predict who is most likely to respond to Avastin and who is not,” says a spokesperson for Genentech, a division of the Swiss pharmaceutical giant Roche, which makes the drug.
That we could be this uncertain about any medicine with $6 billion in annual global sales — and after 16 years of human trials involving tens of thousands of patients — is remarkable in itself. And yet this is the norm, not the exception. We are just as confused about a host of other long-tested therapies: neuroprotective drugs for stroke, erythropoiesis-stimulating agents for anemia, the antiviral drug Tamiflu — and, as recent headlines have shown, rosiglitazone (Avandia) for diabetes, a controversy that has now embroiled a related class of molecules. Which brings us to perhaps a more fundamental question, one that few people really want to ask: do clinical trials even work? Or are the diseases of individuals so particular that testing experimental medicines in broad groups is doomed to create more frustration than knowledge?
Researchers are coming to understand just how individualized human physiology and human pathology really are. On a genetic level, the tumors in one person with pancreatic cancer almost surely won’t be identical to those of any other. Even in a more widespread condition like high cholesterol, the variability between individuals can be great, meaning that any two patients may have starkly different reactions to a drug.
More at the NYT.
And yet the entire health care system is being pushed toward less personalization and more uniformity.
It will cause plenty of problems no doubt. Do poor people really have a shot in a world where medicine is personalized?
Yes. Obviously the labor of personalized medicine is significant, but technology is the key. Allowing freedom into health care would definitely bring down costs and allow access to health care for people of all incomes.
“That we could be this uncertain about any medicine with $6 billion in annual global sales — and after 16 years of human trials involving tens of thousands of patients — is remarkable in itself.”
We’re still trying to fit a square peg in a round hole.
“Researchers are coming to understand just how individualized human physiology and human pathology really are. On a genetic level, the tumors in one person with pancreatic cancer almost surely won’t be identical to those of any other.”
It would be a lot easier to help people if this weren’t the case.
Disease risk, and the effectiveness of cures, are not only affected by genetics, but epigenetics — the expression of genes, which may be permanently altered by an individual’s developmental history and environmental exposure. Epigenetics may complicate treatment, but also open new avenues of treatment — by switching genes on or off.
Truth of the matter is that we know so very little about genetics and microbiology, which makes it all the more complicated to try to find cures to illnesses requiring us to have a much more developed understanding of these.
Many medicines work only marginally better than a placebo. However, a placebo works better than nothing at all. All this doesn’t exactly lend itself to having confidence in the medicines we all take.
My thoughts exactly. We shouldn’t be surprised since most medicines we already take don’t “cure” anything, but merely alleviate the symptoms.
But how are you going to find out what causes the effective disparity without “looking at hundreds of potential predictive biomarkers” in clinical trials.
@Cory–
The point is that at the current state of knowledge one cannot know what works. Therefore, the ObamaCare push to treat medicine as an industrial process with practice guidelines and evidence-based medicine (meaning treat according to average results from a genetically unknown sample of people) will do a great deal of harm.
It means that you have to try things and see how they work rather than running the system on high from some set of academic precepts.
And a lot of biomarkers don’t tell us much because we don’t understand the operation of the systems that they are markers in.
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