Determining the presence of the androgen receptor splice variant 7 (AR-V7) in prostate cancer patients prior to treatment could potentially save the US healthcare system $150 million each year, according to a study published in The Prostate.
The presence of AR-V7 can confer resistance to abiraterone and enzalutamide, two widely used therapies for advanced prostate cancer. Researchers led by Emmanuel S. Antonarakis, MD, assistant professor of oncology at Johns Hopkins University in Baltimore, Maryland, sought to determine whether AR-V7 testing among men with metastatic castration-resistant prostate cancer (CRPC) would result in decreased costs for the US healthcare system.
The test would spare men who were AR-V7-positive (AR-V7 > 5%) from incurring the cost of treatment with either abiraterone or enzalutamide, Antonarakis told Cancer Network. Currently, abiraterone and enzalutamide cost approximately $7,000 per month, and it can take 3 months of treatment for clinicians to determine if the therapy is working.
“We had hypothesized that AR-V7 testing would lead to cost savings by avoiding the expense of abiraterone and enzalutamide in AR-V7-positive patients, in whom these drugs would be expected to be largely ineffective,” said Antonarakis. “But we were surprised when we discovered that these cost savings might be as high as $150 million per year” in the United States.
There are approximately 30,000 men in the United States with metastatic CRPC, according to the study, and the prevalence of those with AR-V7 is about 30%. The researchers estimated that the AR-V7 test would cost $1,000 per patient.
“The remarkable thing was that AR-V7 testing would still be cost-effective even if the prevalence of AR-V7 detection was as low as 10%, or if the cost of the AR-V7 assay was as high as $2,000 per test,” Antonarakis noted.
Next, the study authors will analyze the potential clinical utility of AR-V7 testing. “In other words,” said Antonarakis, “does AR-V7 testing result in changes to the decision-making process in the clinic and how?”
For this analysis, the researchers will send questionnaires to all physicians who are ordering clinical-grade AR-V7 tests at Johns Hopkins and ask them how the test results will change their management of patients.