This is a multicenter, randomized, double-blinded phase 3 study to assess efficacy and safety of two different doses of ianalumab versus placebo in addition to eltrombopag in adults with primary ITP (platelet count \<30 G/L) who failed previous first-line treatment with corticosteroids.
After completion of the screening period, the participants will enter the randomized treatment period (ianalumab/placebo with eltrombopag) followed by the eltrombopag tapering period. Afterwards, all participants will enter the follow-up period to be monitored for efficacy and safety or safety only depending on how the participants responded to the study treatment.