CLDN18.2 x TOP1

The purpose of this study is to assess the safety, tolerability, efficacy, pharmacokinetics (PK), and immunogenicity of AZD0901 as monotherapy and in combination with anti-cancer agents in participants with locally advanced unresectable or metastatic solid tumours expressing CLDN18.2.

Claudin 18.2 protein, or CLDN18.2 is a protein found on cells in the digestive system. It is also found on some tumors. Researchers are looking at ways to attack CLDN18.2 to help control tumors. ASP2138 is thought to bind to CLDN18.2 and a protein called on a type of immune cell called a T-cell. This "tells" the immune system to attack the tumor.
ASP2138 is a potential treatment for people with stomach cancer, gastroesophageal junction cancer, (GEJ cancer) or pancreatic cancer. GEJ is where the tube that carries food (esophagus) joins the stomach). Before ASP2138 is available as a treatment, the researchers need to understand how it is processed by and acts upon the body. In this study, ASP2138 will either be given by itself, or given together with standard treatments for gastric, GEJ and pancreatic cancer. Pembrolizumab and mFOLFOX6 (modified leucovorin [folinic acid], 5-FU [fluorouracil], and oxaliplatin), and ramucirumab and paclitaxel are standard treatments for gastric and GEJ cancer. mFOLFIRINOX (modified leucovorin [folinic acid], 5-FU [fluorouracil], irinotecan and oxaliplatin) is a standard treatment for pancreatic cancer. This information will help to find a suitable dose of ASP2138 given by itself and together with the standard cancer treatments and to check for potential medical problems from the treatments.
Adults 18 years or older with stomach cancer, GEJ cancer, or pancreatic cancer can take part. Their cancer is locally advanced unresectable or metastatic. Locally advanced means the cancer has spread to nearby tissue. Unresectable means the cancer cannot be removed by surgery. Metastatic means the cancer has spread to other parts of the body.
The main aims of the study are to check the safety of ASP2138, and how well people cope with (tolerate) any medical problems during the study, and to find a suitable dose of ASP2138 to be used later in this study. These are done for ASP2138 given by itself and when given together with the standard cancer treatments.
The study will have 2 phases. In phase 1, different small groups of people will receive lower to higher doses of ASP2138 given by itself or together with the standard cancer treatments. Any medical problems will be recorded at each dose. This is done to find suitable doses of ASP2138 to use later in the study. Doctors will also check how each type of cancer responds to ASP2138. In phase 1b, other different small groups will receive suitable doses of ASP2138 given by itself or together with the standard cancer treatments. Suitable doses will be found from phase 1. Phase 1b will check how each type of cancer responds to ASP2138 given by itself or together with the standard cancer treatments. The response to ASP2138 is measured using scans and blood tests. Safety checks will be done at each visit and the doctors will continue to check for all medical problems throughout the study.
ASP2138 will be given either through a vein (intravenous infusion) or just below the skin (subcutaneous injection). Treatment will be in a 14-day cycle (2 weeks). In each treatment cycle, intravenous infusions or subcutaneous injections will either be given once a week or once every 2 weeks.
People will continue to receive treatment until their cancer gets worse or the doctor decides to stop the person's treatment. People will visit the clinic on certain days during their treatment, with extra visits during the first 3 cycles of treatment.
After treatment has finished, people will visit the clinic for a health check several times. The number of visits and checks done at each visit will depend on the health of each person and whether they completed their treatment or not.