The LUNA 3 study is for teenagers and adults (ages 12 and up) with primary immune thrombocytopenia (ITP) for which standard medications are no longer working. The goal of the study is to see if the study drug, Rilzabrutinib can safely increase platelet counts and improve symptoms for people with ITP. Rilzabrutinib is an investigational medication designed to stop your immune system from destroying your platelets. You may be able to join the study if you are:

• 12 years of age or older.
• Diagnosed with primary ITP for at least 6 months for ages 12 through 17 or for at least 3 months for ages 18 and up.
• Have taken IVIg or steroids, but they are no longer working.
• Have platelet counts of less than 30,000. 

Other study requirements will apply.