Study of Efficacy and Safety of JDQ443 Single-agent as First-line Treatment for Patients With Locally Advanced or Metastatic KRAS G12C- Mutated Non-small Cell Lung Cancer With a PD-L1 Expression < 1% or a PD-L1 Expression ≥ 1% and an STK11 Co-mutation.

This study aims to evaluate the antitumor activity and safety of JDQ443 single-agent as first-line treatment for participants with locally advanced or metastatic non-small cell lung cancer (NSCLC) whose tumors harbor a KRAS G12C mutation and have a PD-L1 expression \< 1% (cohort A) or a PD-L1 expression ≥ 1% and an STK11 co-mutation (cohort B).

This is a non-randomized, open-label, single-arm, multicenter, phase II study evaluating the antitumor activity and safety of JDQ443 single-agent as first-line treatment for participants with locally advanced or metastatic KRAS G12C-mutated NSCLC. The study will have 2 non-comparative cohorts that will recruit participants in parallel according to the following characteristics: * Cohort A: participants whose tumors harbor a KRAS G12C mutation and a PD-L1 expression \< 1%, regardless of STK11 mutation status. * Cohort B: participants whose tumors harbor a KRAS G12C mutation, a PD-L1 expression ≥ 1% and an STK11 co-mutation. The study treatment begins on Cycle 1 Day 1 (C1D1) with the first administration of JDQ443. One treatment cycle consists of 21 (±3) days. Study completion is defined as the earliest occurrence of one of the following: * The last participant completes last study visit (and the assessments associated with this visit have been documented and followed-up appropriately by the Investigator), dies, withdraws consent, or is lost to follow-up, whichever comes first.\] * In the event of an early study termination decision, the date of that decision. * Another clinical study becomes available that can continue to provide JDQ443 to study participants and all participants with ongoing treatment are transferred to that clinical study.