ACT is also meant to help the patient be committed to making changes, in order to thrive with the disease.
Aside from acceptance, ACT also helps the patient commit to making the changes in their lives to thrive despite the disease. It's much easier to change someone's behavior if the person is committed and understand and accepts why these changes are necessary.
Changes might be as simple as changing a diet or as difficult as joining a trial to test new treatment options. So far, any research around ACT has shown that it's successful.