Demonstrating prognostic power
Myriad Genetics’ EndoPredict test gets early support from doctors for predicting recurrence of breast cancer
SALT LAKE CITY—Just six weeks after a podium presentation at the San Antonio Breast Cancer Symposium (SABCS), molecular diagnostics leader Myriad Genetics Inc. was already reaping the rewards of EndoPredict’s successful study showing the second-generation multigene test has outperformed its rivals in predicting the long-term recurrence of breast cancer. A key benefit of EndoPredict is its ability to identify patients who can forgo chemotherapy, a treatment that leaves patients in a debilitating and weakened condition.
The Dec. 9 presentation of the EndoPredict study created a buzz among physicians and other healthcare providers, including Medicare.
“Since December, we have made substantial progress with managed care coverage for EndoPredict during the first quarter,” says Ron Rogers, executive vice president of corporate communications at Myriad.
“We have also submitted our dossier to Medicare for EndoPredict reimbursement,” Rogers told DDNews, adding, “It is unprecedented in our experience to see this level of payer coverage and interest prior to a diagnostic launch, which will happen in the second half of this fiscal year.”
In addition, the Integrated Oncology Network (ION) recently declared EndoPredict the preferred test for their physicians, according to Rogers. ION is the largest physician service organization specializing in community oncology, representing approximately 50 percent of community oncologists.
“We continue to receive strong interest from physicians following the TransATAC study, where EndoPredict demonstrated that it had four times the prognostic power of the market leading first-generation multigene prognostic test, Oncotype Dx, particularly in years five to 10,” Rogers notes. “Additionally, physicians like the lack of an indeterminate intermediate result and like the fact that EndoPredict can identify a larger subset of patients who can safely forgo chemotherapy.”
EndoPredict has been validated in approximately 4,000 patients with node-negative and node-positive cancer and has been used clinically in over 13,000 patients, he says. In contrast to Oncotype Dx, EndoPredict detects the likelihood of late metastases (after more than five years) and therefore can guide treatment decisions regarding the need for chemotherapy, as well as extended anti-hormonal therapy.
Led by scientists at the Institute of Cancer Research in London, the EndoPredict analysis included 818 women with ER+/HER2- breast cancer (591 node-negative; 227 node-positive) from the TransATAC study and compared the power of six predictive signatures, including: clinical treatment score, immunohistochemical markers, Oncotype Dx recurrence score (RS), breast cancer index (BCI), Prosigna and EndoPredict (EPClin).
Distant recurrence of breast cancer was the primary endpoint and the median follow-up period was 10 years.
Overall, each of the three second-generation tests evaluated (BCI, Prosigna and EndoPredict) outperformed Oncotype Dx in this cohort in predicting the recurrence of breast cancer in both node-negative and node-positive patients across both zero to 10 and five to 10 years post-surgery.
In a head-to-head comparison between EndoPredict and Oncotype Dx, EndoPredict offered more predictive power than Oncotype Dx across zero to 10 years. The data show that the likelihood ratio (LRx2, a common measure of predictive power) for EndoPredict was almost double that of Oncotype Dx in node-negative patients and was five times higher in node-positive patients. Myriad's test also provided superior predictive power over Oncotype Dx between five to 10 years, with a likelihood ratio for EndoPredict seven times higher than for Oncotype Dx in node-negative patients and 13 times higher in node-positive patients.
Importantly, the likelihood ratio for Oncotype DX failed to achieve statistical significance in predicting cancer recurrence in years five to 10 for either node-positive or node-negative patients, indicating an inability to predict distant recurrence over the five to 10-year timeframe.
EndoPredict was also superior in classifying node-positive patients as low-risk compared to Oncotype Dx. Node-positive patients classified as low risk by EndoPredict had a substantially lower 10-year recurrence rate (5.6 percent) than patients classified as low risk by Oncotype Dx (26.2 percent); as well as a lower five to 10-year recurrence rate (3.3 percent for EndoPredict vs 17.9 percent for Oncotype Dx).
About 80 percent of primary breast cancers are estrogen receptor-positive disease, and such patients receive adjuvant endocrine therapy after surgery that markedly improves their prognosis.
A large proportion of patients receiving endocrine therapy have sufficiently low risk to safely avoid chemotherapy, the study states. Differentiating these patients from higher-risk patients who may benefit from adjuvant chemotherapy is a priority for breast cancer management.
In other news, Myriad has announced new findings from the OlympiAD study that show its BRACAnalysis CDx test successfully identified patients with HER2-negative metastatic breast cancer who have BRCA mutations and who had improved response with Lynparza (olaparib), AstraZeneca’s PARP inhibitor.
The high level results are the first reported clinical data from the OlympiAD study which assessed the efficacy and safety of olaparib monotherapy versus physicians’ choice of chemotherapy (i.e., capecitabine, vinorelbine or eribulin) in the treatment of metastatic breast cancer.
Of the 302 patients in the study, 98 percent (297/302) tested positive for germline BRCA1/2 mutations as determined by Myriad’s FDA-approved BRACAnalysis CDx test. The results demonstrated a statistically significant improvement of progression-free survival among BRCA-mutated patients treated with olaparib compared to those treated with physicians’ choice.