Rilzabrutinib for the Adult Participants With Chronic ITP Who Have Completed Phase 3 Study in Japan

Inclusion Criteria: * Participants who have been enrolled in and have completed the LTE of the LUNA 3 study with demonstration of efficacy without major safety concern while on study considered by the Investigator to be clinically meaningful. * Participants who have ongoing diagnosis of primary ITP and continue to require treatment for ITP according to the Investigator. * Participants who have acceptable benefit/risk profile. * Contraceptive use by men and women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies. Exclusion Criteria: * Participants with secondary ITP. * Pregnant or lactating women. * Electrocardiogram (ECG) findings for participants. The above information is not intended to contain all considerations relevant to a participant's potential participation in a clinical trial.