Pharmacogenomics evolves toward personalized medicine

October 1, 2006

With about 2,000 genes now identified and more than 4,000 diseases caused by genetic defects, genetic screening is gaining ground. As it grows in acceptance by providers, patients and insurers, pharmacogenomics-the study of how one's genetic inheritance affects the body's response to drugs-is evolving. People will be able to determine if they are predisposed to a certain disease, and they will be able to find customized drugs adapted to their personal genetic makeup.

WITH ABOUT 2,000 GENES now identified and more than 4,000 diseases caused by genetic defects, genetic screening is gaining ground. As it grows in acceptance by providers, patients and insurers, pharmacogenomics-the study of how one's genetic inheritance affects the body's response to drugs-is evolving. People will be able to determine if they are predisposed to a certain disease, and they will be able to find customized drugs adapted to their personal genetic makeup.

Pharmacogenomics potentially opens the door to improved, safer and more powerful drugs, accurate methods for determining appropriate drug dosages, a decrease in overall cost of healthcare and more efficiency in drug discovery and approval. It is a huge step toward personalized medicine, which uses detailed information about a patient's genotype and clinical data in order to select a medication, therapy or preventive measure that is suited to that patient.

As many as 91% strongly/somewhat support research by scientists to find ways to prevent or treat diseases, but as many as 80% strongly/somewhat oppose the use of data by health insurance companies to determine whom to insure and at what rate, while 81% think that way about data use by employers.

UNDER ONE UMBRELLA

Kaiser Permanente, Northern Region, offers a comprehensive genetic screening program under one umbrella, targeting prenatal, newborn, pediatrics, adults and cancer. Its own lab screens for common genetic diseases, such as Tay-Sachs and cystic fibrosis, conducted by genetic specialists; however, any physician may order a test.

"If the result has a clinical impact on family history and on whether a woman decides to conceive, then the test is worthwhile," says Ronald Bachman, MD, chief, department of genetics for the region headquartered in Oakland, Calif. "We certainly don't encourage testing just for the sake of testing."

Dr. Bachman says more genetic screenings are generated by patients to check their predisposition to a disease. Genetic testing may also pinpoint who is at high risk for a certain disease and enable aggressive preventive measures, such as semi-annual mammograms, MRIs at an early age or even surgery. Dr. Bachman notes that genetic screenings may discover defects prenatally.

"The important issue is understanding what a test will tell or not tell and what implication that has for a patient and his or her family," Dr. Bachman says. "Once a gene is discovered in an individual, that information will be put into a patient's medical record. Although some are concerned about possible genetic discrimination, there have only been a few instances of this."

ADOPTING GUIDELINES

Aetna, based in Hartford, Conn., has been progressive in its support of genetic testing and pharmacogenetic therapies, adopting and developing coverage and privacy guidelines for genetic testing in 2002. The guidelines were then adopted by America's Health Insurance Plans.

Aetna covers genetic testing for those members at risk, when the results could affect the course of treatment, and for a family member who is not otherwise insured if the results could affect treatment of an at-risk, insured member. In addition, the health insurer covers consultations with qualified counselors and physicians, facilitates appropriate interpretation of genetic testing results, supports physician education in the interpretation of genetic tests and pharmacogenetic therapies and protects the confidentiality of genetic information. Its guidelines also prevent testing results from affecting healthcare coverage. Both breast cancer and hepatitis C have entered the realm of pharmacogenomics at Aetna.

"We can use genetic information to tailor the right drugs to those with hepatitis C," says Joanne Armstrong, MD, senior medical director for Aetna.

The health plan created a hepatitis C management program in 2005 to ensure that patients are being treated appropriately-not just with drug therapy but also in terms of disease management. Once put on the right drug, patients are screened every 12 weeks and assessed for compliance, as well as for comorbidities.

Dr. Armstrong says that there are 2,200 hepatitis C patients on therapy, with 10% to 15% not receiving drugs based on clinical evidence. Aetna has saved $4 million from the optimization of therapy and compliance.

A bit in the future, Aetna will assess the HER2 gene, whose amplification status is essential to understanding how to treat breast cancer. When the HER2 gene is amplified, certain breast cancer treatments are more appropriate.

"Genetics holds the promise of finding selected therapies so we can get it right the first time," Dr. Armstrong says.

NOT AN ARBITRARY DECISION

SelectHealth, an insurer based in Salt Lake City, is selective in its use of genetic testing, says Roy Gandolfi, MD, associate medical director. "We set criteria for those who would be likely to have a genetic defect causing cancer and other chronic diseases when there is a family history or they have certain traits which would lead to these disease states," he says. "No prior authorization is needed on genetic tests that have been evaluated and approved by SelectHealth's medical technology committee."

Mari Edlin is a frequent contributor to MANAGED HEALTHCARE EXECUTIVE. She is based in Sonoma, Calif.

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