Safety, Tolerability, Pharmacokinetics (PK), Pharmacodynamics (PD) and Preliminary Efficacy of VIT-2763 in β-thalassaemia

Inclusion Criteria: * Documented diagnosis of NTDT, including a β-thalassemia intermedia-phenotype. * NTDT is defined as subjects having received less than 5 units of red blood cells (RBCs) during the 24-week period prior to randomisation/first drug administration of VIT-2763 or placebo (Day 1; 1 unit is defined as 200 to 350 ml of transfused packed RBCs and last RBC transfusion must have been received at east 14 days prior to randomisation). * Male and female adult NTDT subjects, 18-65 years of age inclusive (Cohort I only) at time of screening. * Male and female adolescent NTDT subjects, 12-17 years of age inclusive (Cohort II only) at time of screening. * Subjects must have a mean baseline hemoglobin (Hb) equal to or lower than 11 g/dl, based on at least 2 consecutive measurements with at least 1 week apart within 6 weeks prior to randomisation/baseline. Exclusion Criteria: * Documented diagnosis of transfusion dependent thalassemia (TDT), including a beta-thalassemia major phenotype (including β0/β0, β+/β+, β0/β+ genotype), and mixed compound heterozygous for sickling phenotype variants such as Hb S/β- thalassemia, or transfusion dependent non-deletional Hb H disease (i.e., Hb constant spring) or Hb C disease. * Subjects on concomitant iron chelation therapy (ICT) or subjects on prior ICT when discontinued less than 4 weeks prior randomisation. If ICT was discontinued at least 4 weeks prior randomization the subject is eligible. * ICT naïve subjects or subjects who discontinued ICT therapy at least 6 months before the screening visit with serum ferritin lower than 150 ng/ml and/or documented liver iron concentration (LIC) equal to or lower than 1 mg/g liver dry weight assessed through magnetic resonance imaging (MRI), or subjects on prior ICT with serum ferritin lower than 300 ng/ml and/or documented LIC lower than 3 mg/g liver dry weight assessed through MRI. * Subjects with transferrin saturation (TSAT) less than 30%. * Subjects with documented LIC greater than 15 mg/g liver dry weight assessed through MRI, or a documented myocardial T2\* less than 20 ms, if available per local practice and retrieved within 24 months prior to randomization. * Adult or adolescent subjects with body weight lower than 40.0 kg or greater than 100 kg at screening. * Chronic liver disease and/or alanine transaminase (ALT), aspartate transaminase (AST) or gamma-glutamyl transpeptidase (GGT) above 3-fold the upper limit of normal (ULN) range at screening. * Estimated glomerular filtration rate (eGFR) less than 30 ml/min/1.73 m2 (according to chronic kidney disease classification Stage 4 or higher), and/or significant albuminuria greater than 30 mg/mmol. eGFR should be estimated according to Chronic Kidney Disease Epidemiology Collaboration formula (CKI-EPI) in adults, and Schwartz formula in adolescents. * Newly diagnosed folate deficiency anemia and/or Vitamin B12 megaloblastic anemia. Subjects with known folate deficiency anemia and/or Vitamin B12 megaloblastic anemia who are on at least 12 weeks stable replacement therapy are eligible. * Any history or clinically important finding of cardiac disorders, such as clinically relevant cardiac arrhythmia, cardiomyopathy, coronary disease, valve disorder, or heart failure according to New York Heart Association classification 3-4. * Subjects with history of partial or total splenectomy within 6 months prior to screening.