Pilot Study to Assess the Safety, PK and Iron Chelating Activity of DST-0509 (Deferasirox) in Thalassemia Patients Refractory to Chelation

This is a multi-center, open-label, two-period cross-over, patient-pilot study comparing DST-0509 to patient's prior ICT (Exjade or Jadenu) administered orally once daily (QD) for 28-days in each period, with a 6-day washout before the first treatment period, between treatment periods, and at the end of the study before patients recommence their prescription regimens. Patients will be randomized to one of two treatment sequences: DST 0509→Exjade/Jadenu or Exjade/Jadenu→DST-0509 (with subjects who were taking Exjade prior to study start receiving Exjade and those taking Jadenu at study start receiving Jadenu). This study is designed to assess the safety, tolerability, evidence of iron chelating activity, and PK profile of DST-0509 compared to Jadenu or Exjade in inadequately responding patients. Up to 36 patients will be randomized 1:1 into one of two treatment sequences (study arms), of which up to 100% may be on Jadenu or Exjade at study entry, or a mix of the two. The planned randomization will assign up to 18 patients in each of two sequences: Sequence A: DST-0509 crossed to Exjade or Jadenu; Sequence B: Jadenu or Exjade crossed to DST-0509. The comparator treatment will be the patient's current chelation treatment. At the end of the study, patients previously on Jadenu or Exjade will revert to receiving their pre-study medication and dose following a 6-day washout period. A sufficient number of patients will be enrolled so there will be no need to replace study drop-outs. Study duration is approximately 14 weeks for each patient.