A Phase 1 Study of ASP1002 in Participants with Metastatic or Locally Advanced Solid Tumors

Study Purpose

ASP1002 is being studied in people with tumors that have spread to nearby tissue (locally advanced) that cannot be removed by surgery (unresectable) or tumors that have spread to other parts of the body (metastatic). Claudin 4 protein, or CLDN4, is a protein found on tumors in different parts of the body. ASP1002 is thought to work by attaching to the CLDN4 protein in the tumor. This switches on the body's immune system to attack the tumor. Before ASP1002 can be used, researchers need to collect information about the safety of ASP1002 and how people with tumors tolerate it. In this study, ASP1002 will be given to humans for the first time. It will either be given by itself or together with other cancer treatments. These include standard chemotherapies (mFOLFOX6, FOLFIRI, TAS-102, pemetrexed, carboplatin, and docetaxel) and immunotherapies (bevacizumab, pembrolizumab, and ramucirumab). Immunotherapy is a treatment that works with the body's immune system to treat tumors. This is an early development study. These studies are mostly about safety, but also to find the most suitable dose. Other aims are to learn if ASP1002 shows signs of slowing down tumor growth, to learn how the body processes ASP1002, and to check if there are changes in the CLDN4 protein or the immune system after treatment. The main aims of the study are to check the safety of ASP1002 by itself and given with standard chemotherapies and immunotherapies in people with solid tumors and how well they tolerate the study treatments, and to find a suitable dose of ASP1002 by itself and in combination with standard chemotherapies and immunotherapies. People in this study will be adults with tumors that have spread to nearby tissue (locally advanced) that cannot be removed by surgery (unresectable) or tumors that have spread to other parts of the body (metastatic). They will have been previously treated with available standard therapies, or they will have refused to receive those treatments. The key reasons people cannot take part are if they have symptoms of cancer in the brain or nervous system, have recently had other cancers that required treatment, or have diseases that affect the immune system or the heart. This study will be in 2 parts. In Part 1, different small groups of people will receive lower to higher doses of ASP1002 by itself and given with chemotherapies and immunotherapies. Any medical problems will be recorded at each dose. This is done to find suitable doses of ASP1002 to use in Part 2 of the study. In Part 2, other different small groups of people will receive doses of ASP1002, the chemotherapies and immunotherapies that worked the best in Part 1. In both parts of the study, ASP1002 will be given by itself and with standard chemotherapies and immunotherapies to people slowly through a tube into a vein. This is called an infusion. This will happen every 2 to 4 weeks, in treatment cycles. Treatment cycles may be 21 or 28 days long. People will continue to receive study treatment for up to 2 years or until their cancer gets worse, they can't tolerate the study treatment, they start other cancer treatments, or the doctor decides the person should stop receiving study treatment, or sadly, they pass away. They can also choose to stop taking the study treatment at any time without giving a reason. During the study, people will visit the clinic several times for a health check. This includes standard safety checks and reporting any medical problems. Every 2 months, the study doctors will check if each person's cancer has stayed the same, shrunk or disappeared over time. This will be done by scans (CT or MRI scans). Tumor samples will be taken during the study, and people will have the option of giving a tumor sample after study treatment has finished. People will have follow-up health checks for up to 1 year after their last dose of study treatment or until they start a different study treatment on a new study, whichever happens first.