Bridging Chemotherapy While Awaiting NGS Results

Estelamari Rodriguez, MD, MPH, explains why patients with advanced non-small cell lung cancer (NSCLC) and high programmed death ligand 1 (PD-L1) expression should not start immunotherapy while biomarker results are pending, since ROS1-positive disease responds poorly to it. She recommends liquid biopsy concurrent with tissue biopsy, which can return RNA results within 7 to 10 days, and cites overlapping liver toxicity and limited brain activity as further reasons to wait. Matthew A. Gubens, MD, MS, says clinicians are never faulted for giving 1 cycle of chemotherapy to buy time for repeat biopsy and next-generation sequencing, and that adding immunotherapy concerns him because its interaction with a later tyrosine kinase inhibitor (TKI) remains uncertain. Julia K. Rotow, MD, switches to a ROS1 TKI immediately once a fusion is found, even during an apparent chemotherapy response, citing far longer progression-free survival with ROS1 inhibitors. The faculty also warn that irreversible immune-related toxicities, such as type 1 diabetes, can follow a false-negative liquid biopsy.