This clinical study is about a new medicine called **ALTA2618**. It is for adults with a special change (mutation) in their genes called **AKT1 E17K** that causes tumors to grow. A tumor is a lump or growth of extra cells that can be harmful. This study is designed to see how safe ALTA2618 is and how it works in the body to fight these tumors. It is an open-label study, meaning everyone knows what medicine they are getting. The study has two parts: **Dose Escalation** to find the best dose, and **Dose Expansion** to see how well it works at that dose.

• The study will check if the medicine is safe and learn the best dose.
• Participants must have tumors that can't be removed or have spread (metastatic).
• You cannot join if you've taken similar medicines before or cannot take pills.