Growing Need for Pharmacogenomics
Pharmacogenetics offers a wide area for research. The knowledge of the effects of polymorphism of genes for the enzymes involved in drug metabolism, like those belonging to the family of cytochrome P450 can be applied in drug delivery, development and the clinical use of drugs.
The cytochrome P450 (CYP) family of liver enzymes is responsible for breaking down more than 30 different classes of drugs. DNA variations in genes that code for these enzymes can influence their ability to metabolize certain drugs. Less active or inactive forms of CYP enzymes that are unable to break down and efficiently eliminate drugs from the body can cause drug overdose in patients.
Today, clinical trials researchers use genetic tests for variations in cytochrome P450 genes to screen and monitor patients. In addition, many pharmaceutical companies screen their chemical compounds to see how well they are broken down by variant forms of CYP enzymes.
Another enzyme called TPMT (thiopurine methyltransferase) plays an important role in the chemotherapy treatment of common childhood leukemia by breaking down a class of therapeutic compounds called thiopurines. A small percentage of Caucasians have genetic variants that prevent them from producing an active form of this protein. As a result, thiopurines elevate to toxic levels in the patient because the inactive form of TMPT is unable to break down the drug. Today, doctors can use a genetic test to screen patients for this deficiency, and the TMPT activity is monitored to determine appropriate thiopurine dosage levels.
Recent research areas involving pharmacogenomics have dealt with how alliances with niche technology providers can boost the commercial potential of the abundance of targets available in the post-genomic era. Various technologies have been integrated to develop personalized therapy in the case of genotyping for drug resistance in HIV infection, personalized therapy for cancer, antipsychotics for schizophrenia, antidepressant therapy, antihypertensive therapy and personalized approach to neurological disorders.
The recent trend concerning methods to maximize sales of pharmacogenomics-derived products reflect pharma’s need to develop portfolios of best-in-segment or ‘multi-buster’ drugs. Also neded, is the application of a proprietary cost-effectiveness framework to assess the therapy areas that are best suited to pharmacogenomics, and the benefits of positioning pharmacogenomics-derived drugs to patients, physicians and healthcare payers.