Mutation-Specific Response to Ramucirumab in EGFR-Mutated Metastatic NSCLC: Insights From Circulating Cell-Free DNA Profiling (Liquid Biopsy Japan Addendum of RELAY Phase 3 Randomized Study)

Introduction: mutation subtypes. Methods: mutation subgroups (ex19del; L858R). Results: 0.0001) and was sustained to follow-up in the RAM plus ERL arm within the L858R subgroup only. cfDNA fragment size decreased from baseline to cycle 4 in the RAM plus ERL arm within both subgroups. T790M rates in the RAM plus ERL and PL plus ERL arms were 22.2% (four of 18) and 52.9% (nine of 17), respectively, in the ex19del subgroup by cycle less than or equal to 155 and 31.8% (seven of 22) and 18.8% (three of 16), respectively, in the L858R subgroup by cycle less than or equal to 176. Conclusions: This updated analysis revealed differences in total cfDNA concentration and T790M mutation rates between ex19del and L858R. RAM plus ERL may exhibit greater antitumor effects on L858R, supporting the favorable survival benefits observed previously in patients with a L858R.