A Phase 1b/2 Study of T-DXd Combinations in HER2-positive Metastatic Breast Cancer

To be considered for this study, you must be at least 18 years old and have breast cancer that has been identified as HER2-positive. This means your cancer has spread (metastatic) or cannot be fully removed by surgery. You also need to have enough of a recent tumor sample to check certain markers.

For some parts of the study, you must have already had at least one treatment for your advanced or metastatic breast cancer, and your cancer has either come back or not responded well to that previous treatment. Other parts of the study are for patients who have not yet had any treatment for their advanced or metastatic breast cancer. The study is open to both men and women.

There are some reasons you might not be able to join. For example, if you have certain heart problems, a type of lung inflammation called ILD/pneumonitis, or an uncontrolled infection. You also can't have had certain previous treatments, like specific types of immunotherapy or particular antibody-drug conjugates, as these might affect the study results.

If you join this study, you will receive one of the experimental drug combinations being tested. The specific medicines and how often you take them will depend on which part of the study you are in. You will have regular visits to the clinic for medical examinations, blood tests, and scans to monitor your health and how the treatment is affecting your cancer. The study involves a dose-finding stage to ensure the correct amount of medication is used, followed by a stage where more patients receive that chosen dose. The total duration of your participation would depend on how your cancer responds to the treatment and the study design, with regular follow-up to check your progress. You will be closely monitored by the study team throughout.