Q702 for the Treatment of Patients With Hematologic Malignancies

This study tests Q702, a drug that targets specific cancer-driving genetic changes, in patients with rare blood and immune system cancers called histiocytic disorders (such as Erdheim-Chester disease, Langerhans cell histiocytosis, or histiocytic sarcoma) that do not have BRAF or MAP2K mutations. **You may be eligible if...** - You are 18 or older - You have a confirmed histiocytic disorder without BRAF or MAP2K gene mutations - Your cancer has relapsed or stopped responding after at least one prior treatment - You are not eligible for or have exhausted standard therapies **You may NOT be eligible if...** - Your cancer has activating BRAF or MAP2K mutations (other targeted therapies may be more appropriate) - You have not yet had a first line of treatment - You do not meet the health criteria set by the treating physician Talk to your doctor to see if this trial is right for you.