These days we frequently hear that precision medicine will change how patients are treated. It is true that precision medicine, alternatively called personalized medicine, will change how diseases are diagnosed and treatments prescribed. However very rarely such reports mention that this near future medicine would be so prohibitively expensive that only limited number of individuals would have sufficient financial resources to benefit from it.
Let me explain my point. In the 20th century, the pharmacological drugs mainly consisted of chemically synthesized small molecules. These drugs would typically target small, conservative regions of the enzymes or receptors to mediate their pharmacological effects (aspirin, β2-blockers, etc). Luckily, big proportion of human population was responsive to such small drugs, though existence of protein variants (alleles) among ethnic groups or sometimes just differences between male and female metabolism affected their relative effectiveness.
One area of medicine that really suffered from generic approach to drug activity was cancer therapy. Since tumors and healthy cells frequently express similar molecules targeted by small chemical drugs, cancer therapy was associated with high level of drug side effects.
One way to overcome drug side effects is to make them more selective, more precise. Now, small molecule chemistry would not have much usefulness here since smaller the region the drug targets, the more non-selective its effect. However, selectivity could be achieved by increasing the size of region targeting by drugs. For example, monoclonal antibodies could interact with the larger area of the target protein and their use could allow more precise differentiation between tumor and healthy cells expressing the same target protein differing in just one (or more) amino acid.
Since every human potentially expresses a unique combination of alleles, application of precision medicine would require availability of pharmacogenomics data for each patients. No matter how easy the host genotyping could become in the future, it still will be more expensive that current generic approach. In addition, genomic data would reveal allele variants selectively expressed by certain ethnic groups. If these ethnic groups would not have political or social-economical resources for whatever reason, big pharma would not spend money to develop allele-selective medicine for these groups, and even if Government would provide financial incentives along the line of orphan drug legislation, it would be still very expensive (as orphan drugs are these days, costing on average between $10,000 to $350,000 per year).
Precision medicine will bring better disease management but current healthcare system would not be able to afford it. However, I think if following conditions are met, precision medicine could work as intended, at least in the US.
1. Introduction of upper limit on cost for each class of drug (based on overall performance and developmental cost).
2. Introduction of upper limit on profits for each class of drug (that would take effect after developmental cost is fully recovered. For example, 100% profit law would mean that if drug development cost was 1 Billion, then the company would be allowed to make 2 Billion in free market and afterwards drug cost would decrease step-wise (10%, each subsequent year), until it reaches manufacturing cost.
3. Increase in Medicare/Medicaid contribution and coverage.
posted by David Usharauli