Patients are prone to confusion regarding the value of genetic and genomic technologies, and providers tend to be untrained in these areas, which slows adoption. Drug reimbursement has been slow, reimbursements for diagnostics remain focused on costs rather than value, and payers do not invest in research and development, even though they benefit from stratification. Many payers and health care providers remain unconvinced that many such therapies improve people’s health or are cost-effective.
In addition to its successes, Trusheim said, genomic-based drug development offers cases where these challenges have so far prevailed. For example, no candidate marker for response to bevacizumab has reached a level of performance acceptable to regulators, and genetic tests for warfarin response have not been widely adopted. FitzGerald added that while it is well established that genetic variants impact warfarin metabolism, there is little change in prescribing practices for testing largely because physicians are reluctant to move away from established measures of anticlotting effects. It also still remains to be seen whether there is an impact on clinical outcomes from utilizing this genetic information. Similarly, FitzGerald said, meta-analyses of multiple studies have not suggested a benefit from segregating patients based on genotype in using clopidogrel, which is a medication used to prevent thrombotic events that has a total of $6-$7 billion in annual sales.
Davies stressed the need to consider what the impact on quality and cost of health care will be from genetic or genomic strategies rather than the activity itself. Translating the multitude of genetic and genomic data into a better understanding of disease, improved targets, rapid translation to the clinic, better patient selection, and increased safety will be crucial, he said. FitzGerald noted that “genomic variation is only one hand clapping” and urged that other variables, such as environmental effects, be integrated with genomic information to fully explore the consequences of drug exposure.3 He also suggested that collaboration with sponsors in small studies that utilize next-generation sequencing and drug-evoked phenotyping of adverse events presents an opportunity for genomic and genetic based strategies.
More generally, Ginsburg concluded, the great expectations generated by the promise of genetic-based drug discovery and development have not always been met (Pollack, 2010). According to a recent article in Clinical Pharmacology and Therapeutics, “the level of trust between the different actors in drug development needs to be urgently restored following the disillusionment felt by many that the sequencing of the human genome did
3 A concept for an integrated data network of genomic and other information is described in Toward Precision Medicine: Building a Knowledge Network for Biomedical Research and a New Taxonomy of Disease (NRC, 2011).