A Phase 2 Study of Cobimetinib in People With Langerhans Cell Histiocytosis and Other Histiocytic Disorders


Full Title

A Phase 2 Study to Assess the Safety and Efficacy of Cobimetinib in Refractory Langerhans Cell Histiocytosis, LCH-Associated Neurodegenerative Disease, and Other Histiocytic Disorders


Researchers are assessing the use of cobimetinib to treat Langerhans cell histiocytosis (LCH) and other histiocytic disorders. Histiocytic disorders are diseases caused by the abnormal function or buildup of immune cells called histiocytes. Cobimetinib works by blocking the activity of a protein called MEK. This protein leads to the abnormal growth and development of histiocytosis cells.

Cobimetinib is already used to treat adults with certain histiocytic disorders. In this study, researchers want to see if it works well in children and teens with LCH and other histiocytic disorders. Cobimetinib is taken orally (by mouth).

Who Can Join

To join this study, there are a few conditions. You or your child must:

  • Have LCH or another histiocytic disorder that came back or got worse even with treatment. Examples include LCH-associated neurodegenerative disorder (LCH-ND), juvenile xanthogranuloma, Erdheim-Chester disease, and Rosai-Dorfman Disease.
  • Be age 6 months to 21 years. People over age 18 must have LCH-ND.
  • Have completed prior histiocytosis treatment at least 4 weeks before taking cobimetinib.
  • May not have taken cobimetinib before.
  • Be able to walk and do routine activities for more than half the time you are awake.


For more information or to see if your child can join this study, please call 833-MSK-KIDS.




Phase II (phase 2)

Disease Status

Newly Diagnosed & Relapsed/Refractory



ClinicalTrials.gov ID