New Oncotype DX Real-World Evidence Shows for the First Time the Practice-Changing Impact of TAILORx Results

• Data obtained in real-life setting from more than 800 patients with node-negative or nodepositive early-stage breast cancer highlight the test’s impact on clinical practice with chemotherapy-sparing effect
• Publication of landmark TAILORx study results led to greater reduction in chemotherapy recommendations

Exact Sciences Corp. today announced results from a prospective clinical survey of the Oncotype DX Breast Recurrence Score test, accepted at the 2020 American Society of Clinical Oncology (ASCO) Annual Meeting, published online in the ASCO meeting library, and expected to be published in the Journal of Clinical Oncology meeting’s proceedings. The findings, consistent with previous studies, further support the unique value of the test in guiding chemotherapy treatment decisions. Results also highlight the practice-changing impact of the landmark TAILORx study1 , which showed that the Oncotype DX test identifies the vast majority of women with nodenegative disease who receive no substantial benefit from chemotherapy (approximately 80%), as well as the important minority (with a Recurrence Score result of 26-100) for whom chemotherapy can be lifesaving.

The survey results2,3 at ASCO20 summarise physicians’ treatment decisions pre- and post-Recurrence Score results in hospitals across Latin America. A total of 647 patients (20% with one to three positive nodes) were enrolled during routine care at 14 community and academic sites in Argentina, Colombia, Mexico, and Peru, while an additional 155 patients (34% with one to three positive nodes) were treated at the largest public breast cancer hospital in Brazil.

The analysis conducted in Argentina, Colombia, Mexico, and Peru included patients treated before and after the June 2018 publication of TAILORx. Overall, the findings revealed a 36% net decrease in chemotherapy recommendations among patients with node-negative disease and a 46% decrease in those with node-positive disease. Importantly, the decrease in chemotherapy recommendations in nodenegative disease was greater following the publication of TAILORx results and went from 28% to 36%.

Of the 155 patients treated in Brazil between August 2018 and April 2019, 70% were classified as having high-risk disease based on traditional clinical parameters, and the majority had tumours larger than 2 centimeters. A total of 151 of the 155 patients (97%) were initially recommended chemotherapy in addition to hormonal therapy based on clinical and pathological features. Based on their Recurrence Score results, 104 of the 151 patients (69%) were spared chemotherapy and received hormonal therapy alone instead.

Results from this public hospital show that clinical and pathological features did not adequately identify patients most likely to benefit from chemotherapy. Testing also led to economic benefits and potential savings, suggesting that the Oncotype DX test should be incorporated in the Brazilian public health system.4

“Our findings highlight the unique value of the Oncotype DX test and the practice-changing impact of the TAILORx results to select patients for chemotherapy and to avoid overtreatment as well as undertreatment,” said Dr. Henry Gómez, lead study author and Head, Breast Cancer Multidisciplinary Team, Oncosalud - AUNA, Lima, Peru. “Overall, the availability of Recurrence Score results led to substantial reductions in chemotherapy use and allowed us to tailor treatment plans more accurately and use resources more effectively.”

These results add to the substantial real-world evidence available for the Oncotype DX test, which reflects its growing adoption, particularly since the publication of TAILORx. This landmark study has positively influenced treatment guidelines and is having an important impact on global reimbursement and standard use of the test. More than 1 million patients around the world have used the test to inform their treatment decision.

“These data align with the findings from a similar survey in the UK which looked at using the Oncotype DX test in node positive early breast cancer patients. The results showed a net decrease in chemotherapy recommendations by over 60% 5 ,” said Andrew Paramore, Director of Medical Affairs, Exact Sciences UK Ltd “As we continue to generate evidence showing the unique value of our test, we look forward to continuing to work with the relevant UK authorities to make it available to a broader patient group”.