The invention relates to 3-heterocyclyl indolyl compounds of formula I capable of inhibiting the interaction between p53, or variants thereof, and MDM2 and/or MDM4, or variants thereof, respectively: wherein R1, R2, R3, R4, RA, Y and Y are as defined in the specification. Due to their activity, the compounds are useful in the treatment of various disorders and diseases mediated by the activity of MDM2 and/or MDM4, or variants thereof, such as inflammatory or proliferative diseases or in the protection of cells.