A Safety Extension Study of Trastuzumab Emtansine in Participants Previously Treated With Trastuzumab Emtansine Alone or in Combination With Other Anti-Cancer Therapy in One of the Parent Studies

This study is for adults, aged 18 or older, who are currently participating in a related cancer study sponsored by Genentech or Roche. To be considered, you must have been receiving trastuzumab emtansine (either alone or with other cancer medicines) or, in some cases, another treatment called the 'control arm' in one of those previous studies.

Crucially, your doctors must believe that you are still benefiting from the treatment you're currently receiving. If your previous study is ending, you must have received your last dose of the study medicine within the last six weeks (42 days) to be able to join this extension study and continue your treatment.

There are also important considerations regarding contraception: if you are a woman who could become pregnant, or a man with a female partner who could become pregnant, you must agree to use highly effective non-hormonal birth control during the study and for a period after your last dose of study medication. This includes not donating eggs for women during this time.

If you join this study, you will continue to receive the same treatment you were getting in the previous study, which is either trastuzumab emtansine (T-DM1) alone or in combination with other anti-cancer medicines like atezolizumab, pertuzumab, trastuzumab, docetaxel, or paclitaxel. The type and schedule of your treatment will depend on what you were receiving before.

Your involvement will include regular visits to the clinic for medical check-ups, blood tests, and to receive your study medication. These visits help your doctors monitor your health and how you're responding to the treatment. The total duration of your participation will depend on how you respond to the treatment and your doctor's assessment, allowing you to continue as long as it's beneficial and safe.