This is a phase 1b, dose escalation and expansion study to evaluate the safety, tolerability, pharmacokinetics and efficacy of JMKX001899 in combination with IN10018 or in combination with chemotherapy or in combination with IN10018 and chemotherapy in subjects with locally advanced or metastatic NSCLC with KRAS G12C mutation.

Inclusion Criteria:

1. Histologically or cytologically documented Stage IIIB or IIIC NSCLC disease not amenable for surgical resection or definitive chemoradiation or Stage IV NSCLC disease.
2. Known KRAS G12C mutation, and negative results for other driver genes with approved targeted therapies.
3. Measurable disease according to RECIST 1.1.
4. An Eastern Cooperative Group (ECOG) performance status of 0 or 1.
5. Adequate organ function.

Exclusion Criteria:

1. Subjects with carcinomatous meningitis or spinal cord compression; or with other evidence indicating that central nervous system (CNS) metastases or leptomeningeal metastases are not yet controlled.
2. Prior chemotherapy, radiotherapy, immunotherapy or treatment with an investigational agent within 4 weeks of receipt of study drug (within 6 weeks for nitrosoureas, mitomycin C; within 2 weeks of small molecule targeted therapies, traditional medicine with anticancer indication).
3. History of prior malignancy in the past 3 years, with the exception of curatively treated malignancies.
4. Gastrointestinal (GI) tract disease causing the inability to take oral medication or affect drug absorption.