The invention relates to a new medicinal use of a substituted chroman compound of formula I wherein each of R1a and R1b is a substituent selected independently from the group consisting of hydrogen and phenyl optionally substituted with 1-3 substituents selected from the group consisting of halogen, hydroxyl, C1-C4 alkyl, C1-C4 alkoxy, C1- C4 alkanoyloxy, R2a and R2b are hydrogen atoms R3a and R3b is C1-C4 alkyl or R3a and R3b together represent an oxo group or together are an C5-C8 alkylene substituent so that together with the carbon atom to which R3a and R3b are attached form a ring, wherein in the main chain to C5-8 alkylene two non-adjacent carbon atoms are replaced by nitrogen atoms, and said C5-C8 alkylene is optionally substituted by a thioxo group, n is the number of the substituents Rz and is an integer from 1 to 3 inclusive, z is the sequence number of the substituent Rz and is an integer from 4 to n + 3, inclusive, (Rz) is a substituent on the benzene ring attached to a non-nodal carbon atom independently selected from the group consisting of hydroxyl, halogen, C2-C6 alkenyl, C1-C4 alkoxy, C1-4 alkanoyloxy, heterocyclic C4-C7 alkyloxy having an oxygen atom in the ring and optionally substituted with 1- 3 substituents selected from the group consisting of C1-4 alkanoyloxy, phenyl-C3-6 alkenyl optionally substituted in the aryl ring by C1-4 alkanoyloxy and substituted in the chain by an oxo group located on a carbon atom adjacent to the carbon atom involved in the double bond C = C, as tautomer, enantiomer, diastereomer, mixture of enantiomers and/or mixture of diastereomers. A compound of formula I is used as an immunosuppressive drug.Linvention concerne une nouvelle utilisation médicale dun composé chromane substitué de formule I, où R1a et R1b sont chacun un substituant choisi indépendamment entre un hydrogène et un phényle facultativement substitué par 1 à 3 substituants choisis au sein du groupe constitué par les halogènes, les hydroxyles, les alkyles
