Evaluate the safety and tolerability of RMC-6236 in adults with specific RAS mutant advanced solid tumors.

This is a Phase 1/2, multicenter open-label study to evaluate the safety, tolerability, pharmacokinetics (PK), and clinical activity of escalating doses of RMC-6236 in adult patients with advanced solid tumors harboring specific RAS mutations, and to determine the maximum tolerated dose (MTD) and/or recommended phase 2 dose [RP2D] within investigated patient population groups. RMC-6236 is a potent, orally bioavailable RAS-MULTI(ON) inhibitor, selective for the active RAS(ON) form of both wild type and mutant variants of the canonical RAS isoforms (HRAS, NRAS, and KRAS).

Inclusion Criteria:

• Histologically confirmed advanced solid tumor with specific KRAS G12 mutations (dose escalation) or RAS mutations (dose optimization/expansion) identified through deoxyribonucleic acid (DNA) sequencing. PDAC with wild-type RAS (expansion).
• Treatment naive or have received prior standard therapy appropriate for tumor type and stage
• Have Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
• Adequate organ function

Exclusion Criteria:

• Primary central nervous system (CNS) tumors
• Active, untreated brain metastases
• Known or suspected impairment of gastrointestinal function that may prohibit ability to swallow or absorb an oral medication
• History of any other unstable or clinically significant concurrent medical condition that would, in the opinion of the investigator, jeopardize the safety of a participant, impact their expected survival through the end of the study participation, and/or impact their ability to comply with the protocol prior/concomitant therapy

Other inclusion/exclusion criteria may apply.