A Trial Testing SP-420 in Subjects With Transfusion-dependent β-thalassemia or Low-risk Myelodysplastic Syndromes

Thalassemia cohorts: Inclusion criteria: * Women and men aged 18 years or older * Transfusion-dependent β-thalassemia including HbE/β-thalassemia requiring iron chelation therapy (β-thalassemia with mutation and/or multiplication of α-globin is allowed) * On a stable dose of iron chelation for at least 4 weeks prior to screening * Weight ≥ 35kg at screening * Transfusion iron overload * Treated and followed for at least the past 6 months in a specialized centre Exclusion criteria: * β-thalassemia with the structural Hb variants HbS and HbC * Current MDS * Current biliary disorder * Historic or ongoing clinically significant kidney disease * Unable to undergo trial assessments including MRI e.g. due to claustrophobia in MRI scanner * Pregnant or nursing women * Men who do not agree to practice effective barrier contraception during the entire period Myelodysplastic Syndromes Cohorts: Inclusion criteria: * Women and men aged 18 years or older * Very low, low, or intermediate risk Myelodysplastic Syndrome according to IPSS-R * Weight ≥ 35kg at screening * Transfusion iron overload * Treated and followed for at least the past 6 months at medical facilities experienced with MDS Exclusion criteria: * Therapy-related MDS or MDS with a known bone marrow fibrosis * Diagnosis of decompensated liver cirrhosis * Clinically significant kidney disease, either historic or ongoing * Uncontrolled ischemic heart disease or uncontrolled arrythmia * Uncontrolled hypertension * Uncontrolled dyslipidaemia * Uncontrolled Diabetes * Major surgery within 8 weeks prior to screening * Pregnant or nursing women * Men who do not agree to practice effective barrier contraception during the entire period