A Phase 1 Study of ASP3082 in Participants With Previously Treated Locally Advanced or Metastatic Solid Tumor Malignancies With KRAS G12D Mutation

ASP3082 is a potential new treatment for people with certain solid tumors. Before ASP3082 is available as a treatment, the researchers need to understand how it is processed by and acts upon the body. This information will help find a suitable dose and check for potential medical problems from the treatment.

People in this study will be adults with locally advanced or metastatic solid tumors with changes in their KRAS gene (G12D mutation). Metastatic means the cancer has spread to other parts of the body. They will have been previously treated with all available standard therapies.

There are 2 main aims of this study. The first is to learn if people with certain solid tumors have any medical problems after receiving different doses of ASP3082. The second is to find a suitable dose of ASP3082 to use in future studies.

This study will be in 2 parts. In Part 1, different small groups of people will receive lower to higher doses of ASP3082. Any medical problems will be recorded at each dose. This is done to find suitable doses of ASP3082 to use in Part 2 of the study. The first group will receive the lowest dose of ASP3082. A medical expert panel will check the results from this group and decide if the next group can receive a higher dose of ASP3082. The panel will do this for each group until all groups have taken ASP3082 or until suitable doses have been selected for Part 2.

In Part 2, other different small groups of people will receive ASP3082 with the most suitable doses worked out from Part 1. This will help find a more accurate dose of ASP3082 to use in future studies.

ASP3082 will be given through a vein. This is called an infusion. Each treatment cycle is 21 days long. They will continue treatment until: they have medical problems from the treatment; their cancer gets worse; they start other cancer treatment; they ask to stop treatment; they do not come back for treatment.

People will visit the clinic on certain days during their treatment, with extra visits during the first 2 cycles of treatment. During these visits, the study doctors will check for any medical problems from ASP3082. At some visits, other checks will include a medical examination, laboratory tests and vital signs. Vital signs include temperature, pulse, breathing rate, and blood pressure. Also, blood and urine samples will be taken. Tumor samples will be taken during certain visits during treatment and when treatment has finished.

People will visit the clinic within 7 days after stopping treatment. The study doctors will check for any medical problems from ASP3082. Other checks will include a medical examination, laboratory tests and vital signs. Then, they may visit the clinic at 30 days and 90 days after stopping treatment. At the 30-day visit, the study doctors will check for any medical problems from ASP3082. People will have their vital signs checked and have some laboratory tests. At the 90-day visit, the study doctors will check for any medical problems from ASP3082 and people will have their vital signs checked. After this, people will continue to visit the clinic every 9 weeks. This is to check the condition of their cancer. They will do this until 45 weeks after treatment stopped, their cancer is worse, they start other cancer treatment, they ask to stop treatment, or they do not come back for treatment.