An independent international consortium has shown the utility of Agendia’s MammaPrint breast cancer prognosis test in accurately identifying which lymph node-positive breast cancer patients should not receive adjuvant chemotherapy. The findings may eventually impact treatment guidelines, according to the company.
The study is one of several that the company has conducted recently in an effort to expand the market for the test: Agendia also recently published data regarding MammaPrint’s utility in reducing chemotherapy treatment in node-negative breast cancer patients, and completed a study that shows the assay might be useful in determining the treatment for elderly patients.
According to data from a study presented by the international TRANSBIG consortium — a translational research network involving 39 partners from Europe and Latin America — MammaPrint accurately identified a low-risk group of lymph node-positive breast cancer patients with excellent survival. These patients, accounting for approximately 30 percent of lymph node-positive patients, will remain free of distant metastases without receiving adjuvant chemotherapy.
“At present, lymph node status is a ‘gold standard’ for use of adjuvant chemotherapy,” Agendia CEO Bernard Sixt told Pharmacogenomics Reporter via e-mail. The new data shows that MammaPrint can identify “patients with one to three positive nodes but [are at] … a low risk of recurrence.
“We expect this new information will eventually be widely adopted as it is very useful, but as with any new information, it will change guidelines over time,” Sixt said.
The TRANSBIG study analyzed 241 tumor samples from breast cancer patients with one to three positive lymph nodes at two hospitals. Patients that MammaPrint classified as “high risk” for recurrence had “significantly worse” five- and 10-year survival rates than patients that were identified as “low risk.”
The results from this study were presented at the San Antonio Breast Cancer Symposium on Dec. 13. Agendia will begin offering MammaPrint to patients having one to three positive lymph nodes in Europe. The company also said it plans to submit this new data to the US Food and Drug Administration “in the very near future.”
Additionally, based on the study findings, the TRANSBIG consortium altered the inclusion criteria of the MINDACT trial, a study comparing traditional methods of assessing cancer risk with determinations made based on tumor gene signatures using MammaPrint. The inclusion criteria will now be expanded to include patients with one to three positive nodes.
According to Sixt, although this new data regarding MammaPrint’s utility in determining the appropriate treatment of lymph node positive patients has the potential to change treatment standards, it will likely be “at least a year before such a change will become part of any guidelines.” However, individual doctors may choose to alter treatment based on this data earlier, he added.
Separately, in the December issue of The Lancet Oncology, researchers from Agendia, the Netherlands Cancer Institute, and others published a study that used MammaPrint to analyze tumors from 585 patients with lymph node-negative, invasive breast cancer, collected at 16 hospitals in The Netherlands. For the 427 patients for whom results were available, MammaPrint classified the patients as having either a “poor prognosis,” conferring a high risk for distant metastasis, or as having “good prognosis,” signaling a low risk for metastasis.
The study authors then compared these results to risk assessments using common guidelines, such as the Dutch Institute for Health Improvement Guidelines, St. Gallen Guidelines, Nottingham Prognostic Index, and Adjuvant! Online. These guidelines use algorithms based on patients’ age, tumor size, and node status to determine if they should receive chemotherapy.
When prognosis was based on the Dutch CBO guidelines, considered the most restrictive, adjuvant chemotherapy was advised less often compared to assessments based on MammaPrint. However, the assay won out when compared to all other guidelines and less adjuvant chemotherapy would be advised based on results of the test.
“We expect this new information will eventually be widely adopted as it is very useful, but as with any new information, it will change guidelines over time.”>
“More than 70 percent of patients who have node-negative breast cancer are successfully treated without chemotherapy. Identifying which patients with breast cancer will most likely require adjuvant chemotherapy is an important step in personalizing a patient’s treatment regimen, and ensuring that patients aren’t receiving unnecessary treatment,” Laura van’t Veer, chief research officer at Agendia, said in a statement.
Agendia expects MammaPrint’s role in determining appropriate treatment in lymph-node positive/negative patients to expand the indicated population for the assay, and in turn expand the company’s market share for this product. “We expect an increase of 25 percent in market size for MammaPrint over the next year, which represents an increase of 120,000 cases annually,” Sixt noted in his e-mail.
For the Elderly
The company is also looking to expand MammaPrint’s indication among elderly cancer patients. Agendia announced this week that it plans to seek expanded FDA clearance for the test in breast cancer patients over the age of 60. The company said it has completed a study that shows the test is useful in assessing the risk of the recurrence of breast cancer in older, post-menopausal patients.
This new “independently validated” information about the test is important because the biology of breast cancer differs between older and younger people, Sixt said in a statement.
In the study, tumors from 100 breast cancer patients with a median age of 62 years were analyzed with MammaPrint. The assay classified patients as being at either low or high risk for distant metastasis. Agendia said that the results were compared to actual outcome of disease in these patients and indicate that MammaPrint is “a very powerful tool to identify older breast cancer patients at low risk for metastatic disease.”
Agendia said it has submitted the study for publication to a clinical research journal, and plans to submit this new data to the FDA to include patients over age 60 as part of the indicated population that can be tested on MammaPrint. The company did not provide a timeline for when it plans to file with the agency.
MammaPrintis the first in vitro diagnostic multivariate index assay cleared by the FDA, which approved the test in February. The agency has also cleared the test for use with Agendia’s RNARetain RNA-stabilizing solution, permitting tumor biopsies to be shipped at ambient temperatures, which in turn lowers shipping costs and allows the company to more broadly distribute the test.
The test measures the activity of 70 genes and provides information about the likelihood of cancer recurrence. All MammaPrint tests are conducted in Agendia’s CLIA-certified central service laboratory in Amsterdam.