Kathryn F. Mileham, MD
Osimertinib (Tagrisso) is predicted to have a significant impact in the first-line setting for patients with EGFR T790M-mutated non–small cell lung cancer (NSCLC), explains Kathryn F. Mileham, MD.
According to results from the FLAURA trial, frontline osimertinib was associated with a 54% reduction in the risk of progression or death versus the standard of care of either erlotinib (Tarceva) or gefitinib (Iressa). In the phase III trial, the median progression-free survival (PFS) was 10.2 months (95% CI, 9.6-11.1) for standard therapy and 18.9 months (95% CI, 12.5-21.4) with osimertinib (HR, 0.46; 95% CI, 0.37-0.57; P
<.0001). Based on these data, the FDA is currently reviewing an application for frontline osimertinib for patients with EGFR
Biomarkers are necessary to determine which patients should receive osimertinib or other targeted therapies based on their mutations. Currently, there are multiple biomarkers identified within NSCLC, including EGFR
, and PD-L1.
“We learned that if we have an effective therapy for these mutations, we need to be testing for them,” says Milehan.
In an interview with OncLive
during the State of the Science SummitTM
on Non–Small Cell Lung Cancer, Mileham, a medical oncologist at Carolina HealthCare System, discussed the development of biomarker testing for patients with mutated NSCLC.
OncLive: What biomarkers are currently identified in NSCLC?
: The landscape of lung cancer has changed so much over the past 20 years. We used to look at lung cancer as small cell lung cancer versus NSCLC. Then we got more specific with the histologic subtypes for treatment purposes that, now, with the discovery of numerous mutations within adenocarcinoma or nonsquamous NSCLC, we have learned much more about biomarkers and biomarker testing in NSCLC.
There are multiple biomarkers within metastatic NSCLC. The most important ones that we are utilizing right now are EGFR
, and PD-L1. Each one of these biomarkers are predicting a response to an oral therapy for EGFR
, and BRAF
inhibitors. Although PD-L1 may not be our best biomarker for response to immunotherapy, PD-L1 expression is predictive of response specifically to pembrolizumab (Keytruda). We can check these in the tissue or plasma. We are still utilizing tissue as our best way to test for biomarkers. Sometimes that may be in a single FDA-approved or companion diagnostic test, whereas other times we may use multiplex sequencing or larger next-generation sequencing.
The advantage of using a broader molecular panel is that we are identifying other biomarkers all identified within NSCLC. They may not have an FDA-approved targeted therapy, but there are numerous clinical trials that are looking at some of these less common mutations. One of those trials is ASCO’s TAPUR trial. This trial gives a patient an opportunity to receive a therapy that is directed at that mutation, but may not yet be FDA approved in that indication.
What are the big questions that community oncologists have regarding biomarker testing?
The biggest challenge for biomarker testing in the community setting is determining which test to give and when. These therapies are giving better responses and better quality of life in improving cancer-related symptoms than their alternative therapy, which is often chemotherapy. If we are in that setting, we need to be testing for them. Currently, every patient with metastatic nonsquamous NSCLC should be checked for mutations in EGFR
, and BRAF
, as well as PD-L1.
What advice do you have for physicians to better understand which biomarker to test for or what to do following a biomarker test?
One of the challenges with biomarker testing in the community setting is not only determining which tests, but how to use the tissue from the sample that was obtained from the tumor. It is important for us to think about this because we need this information and, if tumor samples are not sufficient, we may not be able to get all the information that we need. We must make sure that our patients are getting large tissue samples and that we are communicating with our pathologist so that they are not misutilizing the tissue that we are collecting.