Histiocytic Disorders, Malignant clinical trials at University of California Health

This is a research study of a drug called cobimetinib in children and adults diagnosed with Langerhans cell histiocytosis (LCH), and other histiocytic disorders that has returned or does not respond to treatment. Cobimetinib blocks activation of a protein called Mitogen-activated protein kinase (MEK) that is part of incorrect growth signals in histiocytosis cells. Four different groups of patients will be enrolled.