COMPASS Pathways plc is a mental health care company in the U.K. and U.S. COMP360 is a psilocybin therapy that has completed Phase IIb clinical trials for the treatment of treatment-resistant depression and is in Phase II clinical trials for the treatment of post-traumatic stress disorder. Known as COMPASS Rx Limited until 2020/08, COMPASS Pathways was incorporated in 2020 and is headquartered in London, the U.K.