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.La présente invention concerne de manière générale le composé : N-((4aS,6aR,6bS,8aR,12aS,14aR,14bS)-1 1-cyano-2,2,6a,6b,9,9,12a-heptaméthyl-10,14-dioxo-1,2,3,4,4a,5,6,6a,6b,7,8,8a,9,10,12a,14,14a,14b- octadécahydropicén-4a-yl)-2,2-difluoropropanamide, ses formes polymorphes, ses procédés de préparation et d'utilisation, ses compositions pharmaceutiques, ainsi que des kits et articles manufacturés associés.