Evidence of disease progression with a new adrenal lesion was seen on a subsequent scan 7.5 months after the selpercatinib treatment...Concurrently, plasma genotyping revealed the re-emergence of KIF5B-RET and RET-RPP38 at an AF of 4.59% and 2.30%, respectively. The original TP53 P190T was again detected at an AF of 12.2%. A high level of MET amplification (copy number ∼17), not previously present, was identified from plasma genotyping at the time of progression ( Fig. 2)...Given her symptomatic recurrence, no tumor re-biopsy was performed at the time of selpercatinib progression.