This phase 3 randomized, double-blind trial studied adults with primary immune thrombocytopenia (ITP) who had an insufficient response or relapse after first-line glucocorticoid therapy. The study tested adding ianalumab at 9 mg or 3 mg per kilogram once monthly for 4 months to eltrombopag, compared to placebo plus eltrombopag. There were 152 participants, with about 50 in each group.
At 12 months, 54% in the 9-mg ianalumab group, 51% in the 3-mg group, and 30% in the placebo group were free from treatment failure. The hazard ratios were 0.55 for the 9-mg dose and 0.58 for the 3-mg dose, meaning ianalumab plus eltrombopag was linked to a longer time to treatment failure than placebo plus eltrombopag. At 6 months, stable response was higher in the 9-mg group (62%) than in the placebo group (39%).
Safety events were generally similar across groups, but serious adverse events were more common in the 9-mg group (16%) than in the 3-mg group (6%) or placebo group (4%). The main reason to be careful is that this is a single phase 3 trial with a 4-month follow-up, and longer-term safety and effectiveness are not yet known.
Readers should see this as promising but early evidence. The study shows a link between ianalumab plus eltrombopag and better outcomes in this group, but it does not prove cause and effect. More research is needed before this becomes standard care.