Weighing Cross-Trial Safety Comparisons and Treatment Holds

Luis E. Raez, MD, of Miami Cancer Institute, and Wade T. Iams, MD, of Tennessee Oncology, consider how to interpret descriptive comparisons between COPERNICUS and MARIPOSA, given median follow-up of 4.9 vs 22 months and no formal statistical testing. The faculty call the lower toxicity rates with subcutaneous amivantamab plus lazertinib promising. Dr Iams sees the short follow-up as the main caveat and attributes the difference largely to the prophylactic regimens. With 8% of participants discontinuing amivantamab because of adverse events, Dr Iams says facial and scalp rash cause him the most trouble, while paronychia has been more manageable with protective dressings and limited topical steroids used alongside dermatology colleagues. Dr Raez recalls 1 discontinuation for scalp toxicity in 2 years and prefers holding treatment and resuming, citing data that brief holds do not compromise outcomes. Dr Iams tells patients that dose interruption, dose reduction, and longer dosing intervals are available.