AMXI-5001 is an orally available dual PARP (poly adenosine diphosphate \[ADP\] ribose polymerase) and microtubule polymerization inhibitor. ATLAS-101 is a Phase I/II, open label, multi-center, non-randomized Dose Escalation and Dose Expansion study in participants with advanced malignancies. Study enrollment is approximately 122 participants. All participants receive oral AMXI-5001, twice daily, as monotherapy. Following Phase I (Dose Escalation) to identify the Maximum Tolerated Dose and the Recommended Dose for use in Phase II, additional participants will be enrolled into the Dose Expansion Phase to further characterize the safety, pharmacology, and clinical efficacy of AMXI-5001.