The present invention relates to the compound: N-((4aS,6aR,6bS,8aR,12aS,14aR,14bS)-11-cyano-2,2,6a,6b,9,9,12a-heptamethyl-10,14-dioxo-l,2,3,4,4a,5,6,6a,6b,7,8,8a,9,10,12a,14,14a,14b-octadecahydropicen-4a-yl)-2,2-difluoropropanamide and polymorphic forms and pharmaceutical compositions thereof for use in the treatment of cancer in combination with immunotherapy, for use in the treatment of conditions associated with oxidative stree caused by mitochondrial dysfunction and for use in the treatment of seizure disorders.