I would like to share three papers, articles that focus on the personalized genomics market with you. Almost 3 years ago, I wrote about that FDA had suggested two genetic markers to be used to determine the minimal starting dose of Coumadin. Later, in a paper, Rosove et al. said that “The value and cost-effectiveness of genetic testing to reduce bleeding or thrombosis rates remain unknown.”
Well, now it seems there is the answer.
Patients who received a test of two genes connected to warfarin sensitivity were 28 percent less likely to be hospitalized for a bleeding episode or blood clot than those whose safe and effective warfarin dosing was determined by traditional trial and error method.
Also researchers have provided the first published example of genome-scale RNA and DNA sequencing of a tumour to aid in clinical decision making and therapeutic choice.
“Utilizing a complete map of the molecular changes within a tumour in a clinical setting represents a world first in the application of this technology,” says Dr. Steven Jones, associate director of the Genome Sciences Centre and professor, Simon Fraser University. “It ushers in the era of personalized medicine in oncology, whereby therapies will be tailored precisely to the genetic make-up of the tumour. I anticipate that in the not too distant future nearly all patient tumours will be characterized in this way as a matter of course.”
And Health Populi reported a very interesting correlation between DTC ads, genetic pre-disposition, and healthy decisions:
A team of researchers now finds that DTC can play an important, positive role in motivating health consumers to adopt healthy behaviors. “The intention to engage in healthy lifestyles was strengthened by exposure to familial risk cues in DTC ads and this effect was mediated through enhanced efficacy to take healthy actions,” the paper concludes. Familial risk cues engendered positive self-efficacy.
Berlin et al. published a very interesting paper in Clinical Pharmacology and Therapeutics about DNATwist which is an online tool for teaching middle and high school students about pharmacogenomics.
DNATwist is a Web-based learning tool that explains pharmacogenomics concepts to middle- and high-school students. Its features include (i) a focus on drug responses of interest to teenagers (e.g., alcohol intolerance), (ii) reusable graphical interfaces that reduce extension costs, and (iii) explanations of molecular and cellular drug responses. In testing, students found the tool and topic understandable and engaging. The tool is being modified for use at the Tech Museum of Innovation in California.
Today I wrote about the issue of genetic testing and warfarin management. And now here is a new article focusing on personalized therapy in lung cancer. Adi F. Gazdar published his thoughts in the New England Journal of Medicine.
Successful examples of targeted therapy include imatinib for the treatment of BCR-ABL–positive chronic myeloid leukemia and the reversible tyrosine kinase inhibitors, erlotinib and gefitinib, for blocking the gene that encodes epidermal growth factor receptor (EGFR) in subgroups of patients with non–small-cell lung cancer.
Overall, the rate of survival of patients carrying an EGFR mutation who were treated with the tyrosine kinase inhibitor was relatively high, as compared with that of historical control subjects who were treated with chemotherapy.
We should be prepared for a lot of similar examples in different fields of medicine in the next few years.
One-third of patients receiving warfarin metabolize it differently and experience a higher risk of bleeding. Research has shown that some of the unexpected response to warfarin depends on variants of two genes, CYP2C9 and VKORC1. The FDA has suggested that these markers should be used to determine the minimal starting dose of Coumadin (warfarin); because patients with variations in these markers may require a smaller dose of Coumadin than those with the normal marker.
“Should We Be Applying Warfarin Pharmacogenetics to Clinical Practice? No, Not Now” is an article Michael H. Rosove, MD, and Wayne W. Grody, MD, PhD published in the Annals of Internal Medicine (subscription needed). What I would like to highlight is the list of key points.
Certain single-nucleotide polymorphisms of the cytochrome P450 CYP2C9 and vitamin K epoxide reductase complex subunit 1 (VKORC1) genes influence warfarin metabolism and sensitivity.
The U.S. Food and Drug Administration has modified warfarin labeling to suggest, but not mandate, consideration of pharmacogenetic testing of these genes; the test is now commercially available.
Testing predicts only about one third of all dosing variations.
The value and cost-effectiveness of genetic testing to reduce bleeding or thrombosis rates remain unknown.
Consideration of clinical factors that influence dosing, conscientious prothrombin time monitoring, and sage dosage adjustment remain extremely important in warfarin management.
Further study is required before routine warfarin pharmacogenetic testing can be recommended.
- This page catalogues drugs with pharmacogenomic information in the context of FDA-approved drug labels and lists drugs with mounting pharmacogenomic evidence.
Promethease is a tool to build a report based on SNPedia and a file of genotypes. Customers of testing services (23andMe, deCODEme, Navigenics, …) can use it to learn more about their DNA. It can also pool the data from multiple testing services. The program runs for approximately 2 hours. If you make an optional $2 payment via Amazon.com the program runs faster.
Actually, I cannot download my genomic data from Navigenics, but will be able to do so after the summer. Anyway, the results can be interpreted as follows:
But if your mother died of a heart attack, or your father has colon polyps, as mine does, it’s pretty clear what the indications are. Genomes themselves give you only—with a few exceptions—percentages. So, it’s not like you put this information up and people are going to stick pins into it. I actually was expecting more medical spam about, you know, “We looked at your genome. You should buy such and such nutri-ceutical.” What will be exciting is when you have hundreds of thousands of these and you say, “Oh, wow. They’re these five genes that seem to interact.” Most things are not a gene. It’s usually a lot of different genes—and then, combined with what you eat and whether you sleep enough and whether you stay warm enough and all these other things—that actually produce a real outcome in a person of being in such and such condition.
My good friend, Chavonne Jones at HumanGeneticsDisorders.com shared a great video with us that focuses on describing the main concept of pharmacogenomics. Read more about this interesting field here.
I added Genome Medicine Journal to the new free medical information tracking tool of Webicina, PeRSSonalized Medicine yesterday so it’s time to say a few words about it.
Genome Medicine is an online peer-reviewed journal which publishes open access research articles of outstanding quality in all areas of medicine studied from a genomic or post-genomic perspective. The journal will have a special focus on the latest technologies and findings that impact on the understanding and management of human health and disease.
In addition to publishing high-quality research, Genome Medicine serves the international research community as a forum for the discussion and critical review of information about all areas of medicine informed by genomic research.
Subjects include, but are not limited to:
- Significant advances in the understanding of the genetics, genomics, and epigenetics of disease
- Computational and systems approaches, including proteomics, metabolomics and transcriptomics, to the understanding and management of disease
- Genomic epidemiology and public health genomics
- The application of genomic and post-genomic technologies to clinical practice, with special emphasis on diagnostics and therapeutics
- Personalized medicine
- Ethical, social and legal issues relating to genomic medicine and personalized medicine
This is the journal that provides content I feel totally close to my heart. So why you should follow it? It has an illustrious editorial board and some incredibly interesting articles such as:
Just to mention a few examples.
Here is the RSS feed of the latest articles.