Professor Richard Barker, Founder & Director, New Medicine Partners
‘Precision medicine’ (PM) to many people implies expensive genomic testing followed by even more expensive drug therapy. Understandably many developing economies believe that this kind of PM is not for them—not yet at any rate. Or at least, not for the general population.
But many of these same economies do not want to be left behind in the precision medicine revolution. I have attended conferences where representatives from such countries, admiring the UK’s 100,000 genomes and BioBank programmes, say: “surely there is something we can do along these lines?”
Well, there is, especially if we—and they—take a broader view of what precision medicine means.
Yes, there is the power of genomics, and there is a case for limited programmes aimed at identifying the unique characteristics of specific ethnic groups, their predisposition to disease and their likely responsiveness to treatment. In may cases genomics programmes in genetically diverse countries like the UK may already have studied groups of those from South Asian, African or Middle Eastern backgrounds. And really well targeted genomics—such as those for familial cardiomyopathy—can be cost-effective in terms of costs per life saved, if applied to high risk cases. And in cancer, we now have simple gene panel tests that can avoid the pharmaceutical and human cost of chemotherapy for post-operative breast cancer unlikely to need such treatment.
Over time, the cost of gene sequencing will fall further, of course, and interpretation of the results using bioinformatics tools will start to bring testing for inherited diseases - that otherwise will cost resources over a lifetime - within what is affordable for middle income countries. Neonatal diabetes is one example: certain simple mutations can result in what can appear to be insulin-requiring Type 1 diabetes. This would call for lifetime, costly insulin therapy, when in the case of some mutations a cheap daily sulphonyl urea drug will suffice to restore normal life.
But beyond genomics, there is a wide range of less sophisticated biomarkers that can guide therapy where ‘trial and error’ medicine is a serious waste of resources, or may result in serious, costly side effects. Renal function tests for those products—including common generic anti-hypertensives—that can cause kidney damage, come to mind.
The power of precision medicine to predict and prevent is surely most relevant in dealing with the epidemic of chronic diseases afflicting all economies with aging populations, especially as they adopt what we call “Western” life styles. In this case we need to adopt Leroy Hood’s “4P” medicine: predictive, preventive, personalized and participatory. Blood pressure, lipid and BMI measurements, combined with simple family history, can create a “cardio-metabolic profile” of an individual. Managing this profile better will result in fewer heart attacks, strokes and can slow the onset of dementia. And we now have powerful and cheap digital tools that can be loaded on the almost ubiquitous smart phones to support the individual’s self care. They can truly personalize and track precision programmes of exercise, nutrition and simple drug therapy.
In fact we can argue that developing economies cannot afford not to adopt such a precision medicine approach!