NEW YORK (GenomeWeb) – An economic model evaluating the impact of Myriad Genetics' Prolaris test on a hypothetical prostate cancer cohort found that the multi-gene expression diagnostic reduced costs by $2,850 per patient tested, which extrapolated over a 10-year period could amount to $6 billion in savings.
Researchers from Myriad and elsewhere presented data from this and two other studies involving Prolaris at the 2014 Society of Urologic Oncology's annual meeting today. Prolaris gauges the expression of 45 genes and assesses prostate cancer patients' risk of disease progression.
In the economic model, the imaginary cohort of patients were followed for a decade based on management and progression assumptions that researchers made in line with published literature and interviews with doctors. For each patient in the analysis, the total cost of care was calculated based on the interventions they received (priced according to published costs of care) and a cost of care was determined factoring in the impact on treatment decisions based on Prolaris test results.
"To assess the model’s sensitivity, each input was changed in a way that lowered or increased cost savings and the overall cost savings was recalculated," researchers led by David Crawford of the University of Colorado at Denver explained in an abstract.
The modeling showed that after factoring in the $3,400 list price for the test, using Prolaris in the care of prostate cancer patients reduced costs by $2,850 per patient over 10 years.
"Savings are due to increased use of active surveillance in low- and intermediate-risk patients, but also from reduced progression rates in high-risk patients with more aggressive disease who transition to multi−modality therapy," researchers concluded. "No single model input, when changed within a range of values, caused the model to show that the test was no longer cost saving."
Additionally, Myriad also presented interim analysis from the PROCEDE1000 study, involving more than 800 newly diagnosed and untreated prostate cancer patients with localized disease. The study showed that Prolaris helped doctors guide personalized treatment strategies, the researchers concluded, "often with major reductions in interventional treatment."
Researchers led by the University of Miami's Mark Gonzalgo recorded more than 100 doctors' initial treatment recommendations through a questionnaire, and then conducted the Prolaris test on prostate biopsy tissues. After the test was administered, researchers issued three questionnaires to the doctors to record how their treatment recommendation changed, what the doctor/physician treatment decision was, and what treatment was actually given after a period of clinical follow up.
"There was a strong statistically significant trend towards reduction in the number of treatments assigned/administered per patient," Gonzalgo and colleagues wrote in their abstract. In particular, based on the test results, doctors chose to reduce by 27 percent their decision to perform radical prostatectomies; cut by 44 percent primary and by 56 percent adjuvant radiation therapies; reduce administration by 46 percent and 66 percent of interstitial and HDR brachytherapies, respectively; and reduce by 33 percent neoadjuvant and by 68 percent concurrent hormonal therapies.
"For every one-unit increase in mortality risk, there was an associated 3.3 percent rise in the odds of increase in treatment (vice-versa for decrease in treatment)," the researchers reported.
Myriad will use these studies to try to bolster Prolaris' coverage among payors. Medicare contractor Palmetto GBA in October issued a draft local coverage determination (LCD) for the test.
Lastly, in a third study, Myriad validated a Prolaris score threshold for determining when a patient should be followed with active surveillance. The results from this study showed that no patients died when their scores fell below 0.80. In another analysis of more than 1,700 patients, 55 percent of patients qualified for active surveillance based on that cutoff.