A Phase 1 Study of XL309 (ISM3091) Alone and in Combination in Participants With Advanced Solid Tumors

This is an early-phase study testing a new drug called XL309 (also known as ISM3091), alone or in combination with other treatments, in people with advanced solid tumors. The study is looking at safety and the right dose. **You may be eligible if...** - You are 18 or older and in good general health (ECOG 0–1) - You have advanced cancer that has stopped responding to standard treatments or for which no standard treatment exists - Your cancer is one of the eligible types, such as: HER2-negative breast cancer with BRCA1/2 mutation, ovarian or pancreatic cancer, prostate cancer, certain lung cancers, or other specific tumor types - Your bone marrow and organs are functioning adequately **You may NOT be eligible if...** - You are not in good enough general health to participate - Your organs (liver, kidneys, blood counts) are not functioning at required levels - You have had recent cancer treatments without adequate recovery time Talk to your doctor to see if this trial is right for you.