PRIMARY OBJECTIVES:~I. Assess the safety and tolerability of MRX-2843 (MRX-2843) when administered along with osimertinib.~II. Establish the recommended phase 2 dose (RP2D) of the tested combinations.~SECONDARY OBJECTIVES:~I. To observe and record anti-tumor activity. II. To perform biomarker profiling in order to identify potential predictive biomarker to optimize treatment efficacy.~OUTLINE: This is a dose-escalation study of MRX-2843.~Patients receive osimertinib orally (PO) once daily (QD) and MRX-2843 PO QD on days 1-28. Cycles repeat every 28 days in the absence of disease progression or unacceptable toxicity.~After completion of study treatment, patients are followed up for minimum of 30 days, or until resolution of treatment-related toxicity to =< grade 1, whichever is longer after removal from study.
This phase Ib trial evaluates the best dose and side effects of MRX-2843 when given in combination with osimertinib in treating patients with EGFR gene mutant non-small cell lung cancer that has spread to other places in the body (advanced). MRX-2843 and osimertinib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth.