Inclusion Criteria:  Age ≥ 18 years. Willing and able to give written informed consent. Have histologically or cytologically confirmed advanced or metastatic solid tumor with a relevant molecular alteration (as applicable). There is no available standard systemic therapy available for the patient's tumor histology and/or molecular biomarker profile; or standard therapy is intolerable, not effective, or not accessible; or patient has refused standard therapy. Recovered from all toxicities associated with prior treatment to acceptable baseline status. Have ECOG performance status of 0 or 1 with an anticipated life expectancy of > 12 weeks. Willing to comply with all protocol-required visits, assessments, and procedures. Able to swallow tablets.  Exclusion Criteria:  Currently receiving another study therapy or has participated in a study of an investigational agent and received study therapy within 4 weeks of the first dose of ERAS-007. Received previous treatment with an ERK inhibitor. Received prior antineoplastic therapy within < 21 days or 5 half-lives, whichever is shorter. Received prior palliative radiation within 7 days of first dose of ERAS 007. Received previous treatment with a MAPK inhibitor that resulted in discontinuation due to unacceptable toxicity. Prior surgery (e.g., gastric bypass surgery, gastrectomy) or gastrointestinal dysfunction (e.g., Crohn's disease, ulcerative colitis, short gut syndrome) that may affect drug absorption. Have any underlying medical condition, psychiatric condition, or social situation that, in the opinion of the Investigator, would compromise study administration as per protocol or compromise the assessment of AEs. Are pregnant or breastfeeding or expecting to conceive or father children within the projected duration of the trial.