Reaching for Consistency with Genetic Testing

Winston Wong, PharmD

June 2010, Vol 1, No 2 - VBCC Perspectives


Recent articles in the New England Journal of Medicine1 and the Journal of the American Medical Association2 note the tremendous increase in the cost of cancer care, which has at least doubled since 1990. The reasons for this steep increase have been attributed to the release and utilization of new medications, in tandem with more sophisticated surgery and radiation techniques. This, combined with an increasing number of patients who are candidates for these new treatment modalities, has resulted in an unsustainable cost trend. As a result, payers—including private insurers, the public sector, and governmental programs—have been forced to consider various options to “blunt” this trend. The usual first course of action is to reduce reimbursement, which does not address the topic of utilization.

From the clinician’s perspective, these new, more sophisticated, and specific medications represent new treatment alternatives for the appropriate population. Identifying that appropriate population involves 2 specific, but necessary, concerns: (1) the appropriate utilization of a specific treatment regimen; and (2) the ability to project the best possible outcome from a treatment regimen for a specific patient in his or her clinical situation. Identifying the appropriate treatment population minimizes unnecessary wasted cost (eg, by identifying patients for whom the regimens will have little chance of resulting in a positive outcome) and reduces risk (ie, of exposing a patient to the adverse effects of a treatment that has little potential clinical benefit). Genetic and biomarker identification can help identify these appropriate populations, and will play an increasingly significant role in these efforts.

Although there are many genetic and biomarker tests and assays on the market today, only a select few have been able to withstand the extensive review needed to determine that the results are consistent, and to consistently correlate to predictions of outcome. The review criteria of theBlueCross BlueShield Association Technology Evaluation Center (TEC) are rigorous, and as a “Blues” plan, TEC serves as the basis of our own evaluations. As a result, the human epidermal growth factor receptor 2 (HER2), OncotypeDx, and KRAS testing are considered as “standard of therapy” today.

These tests allow us to determine and identify the most appropriate populations for treatment. The HER2 test, for example, allows us to predict the effectiveness of Herceptin (trastuzumab) therapy in women with breast cancer; the OncotypeDx test allows us to predict the longterm clinical benefit of adjuvant chemotherapy. It is estimated that nearly 50% of women with breast cancer who are candidates for adjuvant chemotherapy following surgery will show no reduction in the risk forrecurrent disease in 10 years, which is significant, given that the cost of a course of adjuvant chemotherapy in our population ranged from $16 000 to $25 000. Finally, the KRAS test was advocated by the National Comprehensive Cancer Network in early 2009 to predict the effectiveness, or lack of effectiveness, of Erbitux/Vectibix (cetuximab/panitumumab) treatment in colon cancer. Erbitux/ Vectibix-based regimens cost between $20 000 and $30 000 per course. On the heels of KRAS, we soon expect the endorsement of the BRAF mutation marker, as well as the absence of the P-TEN marker, to identify an additional 30% of the potential Erbitux/Vectibix treatment population where these agents will not be effective.

In summary, genetic testing and biomarker identification is a significant step in the right direction of predicting the clinical outcome of a treatment regimen, preventing unnecessary patient exposure to adverse effects, and avoiding the expenditures associated with administering ineffective chemotherapy. Numerous tests to help better target therapies are available on the market today. The burden rests with the payers to evaluate these tests and determine whether their results are consistent enough, and if these results are predictive to outcomes. Although the final outcome of the Myriad Genetics case has yet to be decided, the issues raised in the legal process—foremost among them patient access to these tests and the patentability of genetic materials—have served to raise awareness of the value of genetic testing and of targeting therapy among the payer community. Surely that is a good thing.

References

1. Bach PB. Limits on Medicare’s ability to control rising spending on cancer drugs. N Engl J Med. 2009; 360(6):626-633.

2. Elkin EB, Bach PB. Cancer’s next frontier: addressing high and increasing costs. JAMA. 2010; 303(11):1086-1087.