Retrospective Observational Study on Infective Complications and Outcome of Patients With ALL Treated With INO

This observational study (no experimental treatment) is tracking outcomes for adult patients with a type of blood cancer called B-cell acute lymphoblastic leukemia (B-ALL) who were treated with a drug called inotuzumab ozogamicin (INO). The study focuses specifically on complications like infections and liver problems that can occur after this treatment. **You may be eligible if...** - You are an adult (over 18) with relapsed or hard-to-treat B-ALL that has a CD22-positive marker - You received inotuzumab ozogamicin (INO) as part of your standard medical care (not as part of another trial) - You had a certain genetic mutation (Philadelphia chromosome-positive ALL) and failed at least one prior targeted therapy **You may NOT be eligible if...** - You received inotuzumab ozogamicin as part of an interventional clinical trial (vs. standard care) Talk to your doctor to see if this trial is right for you.