Study of JMBI-001 in Patients With MYC-Positive Advanced Cancers

The purpose of this clinical trial is to investigate JMBI-001 for the treatment of MYC-positive advanced tumors and to evaluate its safety, tolerability, pharmacokinetics (PK), preliminary antitumor activity, and antitumor efficacy. The main questions this study aims to answer are: 1. To evaluate the safety, tolerability, PK, and preliminary antitumor activity of JMBI-001, and to determine the recommended dose for expansion (RDE) and the recommended Phase II dose (RP2D). 2. To evaluate the antitumor efficacy, safety, tolerability, and PK of JMBI-001 at the RP2D in selected tumor types. Participants will: 1. Take JMBI-001 orally once daily on an empty stomach for 4 consecutive days, followed by 3 days without treatment. Three such 7-day dosing periods will constitute one 21-day treatment cycle. 2. Visit the study site as scheduled to undergo protocol-specified procedures, including medical interviews, physical examinations, blood tests, electrocardiograms, and imaging examinations. 3. Continue treatment until a protocol-defined event requiring discontinuation of study treatment or withdrawal from the study occurs.