Study of DCC-3084 in Participants With Advanced Malignancies Driven by the Mitogen-Activated Protein Kinase (MAPK) Pathway

Inclusion Criteria:

General Inclusion Criteria ModA Part 1 and 2:

• Able to take oral medication

• If a female is of childbearing potential, must have a negative pregnancy test priorto enrollment and all participants agree to follow the contraception requirements

• Adequate organ function and electrolytes

• Eastern Cooperative Oncology Group Performance Status (ECOG-PS) of 0 to 1 atScreening

• Has a life expectancy of more than 6 months

• In addition to these general inclusion criteria, participants must meet all themodule cohort-specific inclusion criteria

Inclusion Criteria ModA Part 1 Cohort Specific:

• Pathologically confirmed diagnosis of solid cancer and documentation of Kirsten ratsarcoma (KRAS), Harvey rat sarcoma virus (HRAS), neuroblastoma ras viral oncogenehomolog (NRAS), v-raf murine sarcoma viral oncogene homolog B1 (BRAF), v-raf murinesarcoma viral oncogene homolog C1(CRAF), and/or neurofibromatosis 1 (NF1) mutation

• Have exhausted all available standard of care therapies that are known to providebenefit for the participant's condition, as judged by the Investigator

Inclusion Criteria ModA Part 2 Cohort Specific:

• Documented BRAF gene mutation

• Pathologically confirmed diagnosis with PD after at least one prior line of therapyin the advanced or metastatic setting

Exclusion Criteria:

General Exclusion Criteria ModA Part 1 and 2:

• Prior treatment with certain BRAF dimer inhibitors

• Female participant is pregnant or lactating

• Received any prior or concurrent medications or therapies known to be prohibitedwith DCC-3084 within 14 days

• Received any prior antitumor therapy or any investigational therapy within aspecified timeframe prior to first dose of DCC-3084

• Known allergy or hypersensitivity to any component of the study drug

• Invasive malignancy within 2 years prior to the first dose of study drug other thanthe study indication or specific types of cancer treated with curative intent

• Have not recovered from all clinically relevant toxicities from prior therapy

• Impaired cardiac function

• History of recent thrombotic or embolic events

• Malabsorption syndrome or other illness that could affect oral absorption

• Major surgery within 28 days of the first dose of study drug

• In addition to the general exclusion criteria, participants will also be excludedbased on the cohort-specific exclusion criteria

Exclusion Criteria: Module A Part 2 Cohort Specific:

• Has known co-occurring mutation of KRAS, HRAS, NRAS, NF1, epidermal growth factor receptor, Phosphoinositide-3-kinase, catalytic, alpha polypeptide (PI3KCA), or Phosphatase and TENsin homolog deleted on chromosome 10 (PTEN)