Study of Emactuzumab for Tenosynovial Giant Cell Tumor (TGCT)

To be considered for this study, you must be over 12 years old and have a confirmed diagnosis of Tenosynovial Giant Cell Tumor (TGCT). Crucially, surgery for your TGCT must not be considered a good option, either because it might worsen your joint's function, lead to a high chance of the tumor coming back quickly, or cause other health issues, or simply because surgery isn't expected to significantly improve your condition.

There are also some important reasons why you might not be able to join. For example, if you are pregnant or breastfeeding, or if you have certain other medical conditions like an active cancer or serious liver problems. You also can't have received certain types of other TGCT treatments or undergone recent surgery, chemotherapy, or radiotherapy within the last three months before the study starts. Your doctors will also check your organ and bone marrow function to make sure you're healthy enough to participate.

If you're a woman who could become pregnant, you'll need to have a negative pregnancy test before starting treatment and agree to use effective contraception throughout the study. You'll also need to be able to understand the study and provide your written agreement to take part.

If you decide to take part in this study, it will involve two main parts. In the first part, which lasts for 24 weeks (about 6 months), you'll have a 2 in 3 chance of receiving the study drug, emactuzumab, and a 1 in 3 chance of getting a placebo (a dummy drug). Neither you nor your doctor will know which one you are receiving during this time. The medication will be given directly into your bloodstream through a drip (an intravenous or IV infusion) once every two weeks, for a total of five doses.

Throughout the study, you'll have regular check-ups to monitor your health and how you're responding to the treatment. These will include physical examinations, blood tests, scans (like X-rays or MRI to look at the tumor), heart checks (ECGs), and questionnaires to understand how you're feeling. After the initial 24 weeks, there will be a longer-term follow-up period.

If you were in the placebo group during Part 1, you might have the option to switch and receive emactuzumab openly in Part 2, if you meet the criteria. If you received emactuzumab in Part 1, you may also have the option for further treatment in Part 2 under specific circumstances. The total duration of your involvement could be quite long, depending on whether you continue into the follow-up and retreatment phases.