Study to Evaluate D-1553 in Subjects With Solid Tumors

Inclusion criteria * Subject with histologically proven, locally advanced, unresectable and/or metastatic solid tumor, for which no standard treatment is available, or the subject is refractory to or intolerant of existing standard treatment. * Subject has KRasG12C mutation in tumor tissue or other bio-specimens containing cancer cells or DNA. Historical, local laboratory result (up to 5 years prior to this study) can be used for Phase 1 subjects. Phase 2 subjects must be tested for KRasG12C mutation by a central laboratory. * Subject has tumor type requirement as follows: advanced or metastatic solid tumors including NSCLC and CRC. * Subject has measurable disease according to RECIST, v1.1. Exclusion Criteria: * Subject with unstable or progressive central nervous system (CNS) metastases. * Subject with acute myocardial infarction, severe/unstable angina; or with cardiac insufficiency of New York Heart Association Functional Classification Grade 2 or above. * Subject has corrected QT interval using Fridericia's formula (QTcF) prolongation at rest, where the mean QTc interval is \> 480 msec based on triplicate measurements of electrocardiogram (ECG). * Subject with stroke or other severe cerebrovascular diseases within 12 months before enrollment; * Subject with interstitial lung disease or acute lung infection not yet recovered including but not limited to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection; * Subject has any history or evidence of substance abuse or medical, psychological or social conditions that may, in the opinion of the investigator, interfere with participation in the study or evaluation of the study results. * Subject has impaired gastrointestinal (GI) function or GI diseases that may significantly alter the absorption or metabolism of oral medications. * Subject has unresolved toxicities from prior anticancer therapy, defined as toxicities (other than alopecia) not yet resolved to NCI CTCAE, v5.0, Grade ≤ 1 (Grade ≤ 2 for peripheral neuropathy). * Subject had major surgery within 4 weeks prior to study intervention administration or last dose of palliative radiation therapy within 2 weeks prior to study intervention administration. * Subject is pregnant or lactating.