Joshua K. Sabari, MD, assistant professor of medicine, NYU Langone's Perlmutter Cancer Center, discusses biomarkers of immunotherapy response in patients with non—small cell lung cancer (NSCLC).

The reliability of PD-L1 expression as a biomarker is up for debate in the field, but Sabari says he still orders PD-L1 testing for his patients and uses the 50% cutoff to define if a patient should receive pembrolizumab (Keytruda) alone or in combination with chemotherapy. He adds that he does this for patients presenting with non—small cell adenocarcinoma as well as those with squamous NSCLC.

Sabari notes that if you parse the data, no matter how you look at it, patients with high levels of PD-L1 expression have a greater chance to benefit from immunotherapy. His treatment approach is to weigh the risks of each therapy with the benefits. For example, if a patient has a PD-L1 expression of 100%, who he knows has a high likelihood of responding to immunotherapy, then chemotherapy can be avoided.

Another key biomarker coming down the pike is tumor mutational burden (TMB), he adds. Although this is a controversial topic, there are studies looking at it prospectively as well as retrospectively. For example, the CheckMate-227 trial, which was recently published, showed an improvement in patients who had high TMB. The controversy, he explains, lies in the question of how to define “TMB-high” and if it is possible to establish a unified definition by looking at different assays.

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Joshua K. Sabari, MD, assistant professor of medicine, NYU Langone's Perlmutter Cancer Center, discusses biomarkers of immunotherapy response in non–small cell lung cancer.

Dr. Sabari Discusses Immunotherapy Biomarkers in NSCLC

Joshua K. Sabari, MD, assistant professor of medicine, NYU Langone's Perlmutter Cancer Center, compares liquid and tissue biopsies for the treatment of patients with advanced non—small cell lung cancer (NSCLC).

Tissue biopsies are still the standard of care because defining the histology of the tumor is critical, Sabari says, but there are factors that give liquid biopsies an advantage. The latter is more accessible, easier to perform, and, importantly, has a much quicker turnaround time. Liquid biopsy assays are able to turn results around in 7 to 10 days, while it takes tissue-based next-generation sequencing (NGS) about 3 weeks to develop, on average.

A study was conducted at NYU Langone, which compared the concordance between tissue NGS and blood-based NGS. Results showed that if an alteration was identified in a liquid biopsy, it was also detected in a tissue biopsy about 97% of the time. While the clinical utility of these assays seems to be comparable, the turnaround time with liquid biopsy was much quicker than that seen with tissue biopsy, an average of 9 days versus 21 days, respectively. This turnaround time allows for patients to be placed on their appropriate treatment plan earlier, which can ultimately improve outcomes, Sabari says.

Joshua K. Sabari, MD, assistant professor of medicine, NYU Langone's Perlmutter Cancer Center, compares liquid and tissue biopsies for the treatment of patients with advanced non–small cell lung cancer.

Joshua K. Sabari, MD

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Dr. Sabari Discusses Immunotherapy Biomarkers in NSCLC

Dr. Sabari Compares Liquid and Tissue Biopsies in NSCLC