Naveed Saleh, MD, MS, for MDLinx | October 11, 2019
As if immunotherapy wasn’t cool enough, there’s now an electronic nose (eNose) that can take a whiff of a patient’s breath to determine their potential response to immunotherapy—with an impressive 85% accuracy rate.
According to the results of a recent prospective study published in Annals of Oncology, eNose technology outperformed gold-standard immunohistochemistry (IHC) in identifying patients with non-small cell lung cancer (NSCLC) who would benefit from anti-PD-1 immunotherapies, including pembrolizumab and nivolumab.
Only 20% of NSCLC patients respond to immunotherapy, and IHC—which is used to identify these patients—suffers from analytic and predictive limitations, according to the authors. It is important to accurately identify those who would benefit from immunotherapy, largely in part because 10% of patients experience serious adverse events from this treatment.
This could all be avoided with better diagnostic technology.
“ENose technology is cheap compared to other available medical technologies and diagnostic tests and biomarkers. The eNose qualifies as a non-invasive and rapid point-of-care test that provides feedback within seconds in the doctor's office. Our results form a solid base for taking the next step to validate these findings in a large prospective multi-center study,” said co-first study author Mirte Muller, PhD student, Department of Thoracic Oncology, Netherlands Cancer Institute, Amsterdam, Netherlands.
The eNose consists of sensors that detect volatile organic compounds (VOCs), which comprise nearly 1% of exhaled breath, with the rest being mostly nitrogen, oxygen, carbon dioxide, and water. VOC concentrations vary according to metabolic processes, including those taking place in the lungs.
The eNose is a small device that the patient exhales into after holding their breath for 5 seconds. Each sensor in the device picks up a different group of molecules, with readings sent to an online server that corrects for ambient air variables. Readings are run through an online database where machine-learning algorithms determine response to anti-PD-1 therapy. Measurements take less than a minute to be determined.
In the current observational study, 143 patients with NSCLC on immune checkpoint inhibitors (training: 92; validation: 51) had breath profiles available at baseline. Sensors in the eNose were able to identify different responses to anti-PD-1 treatment at 3 months of treatment. According to results from the validation set, anti-PD-1 therapy could be obviated in 24% of patients with NSCLC who don’t need it.
In previous research, the eNose was able to detect epidermal growth factor receptor mutations, and has been shown to provide clinical and inflammatory phenotyping with regard to point-of-care testing in chronic airway disease—opening the door to precision anti-inflammatory therapeutic approaches.
“Given the clinically applicable technology,” wrote the authors, “the present data may qualify breath assessment as a real-time tool for stratification of patients with NSCLC. This meets the demands of modern medicine, in which treatment decisions are taken based on the patient’s individual subtype rather than a classical diagnosis.”