A Study of Selpercatinib After Surgery or Radiation in Participants With Non-Small Cell Lung Cancer (NSCLC)

The reason for this study is to see if the study drug, selpercatinib, compared to placebo is effective and safe in delaying cancer return in participants with early-stage non-small cell lung cancer (NSCLC), who have already had surgery or radiation. Participants who are assigned to placebo and stop the study drug because their disease comes back or gets worse have the option to potentially crossover to selpercatinib. Participation could last up to three years.