A 15 y.o. patient has a developmental lag, occasionally he has skin yellowing. Objectively: spleen is 16x12x10 cm, cholecystolithiasis, skin ulcer of the lower third of left crus. Blood count: RBC- 3,0 × 1012/l, Hb- 90 g/L, C.I.-1,0; microspherocytosis, reticulocytosis. Total serum bilirubin is 56 mcmol/L, unconjugated - 38 mcmol/L. What therapy will be the most appropriate?