There were three studies in the Phase II trial. Study 1 demonstrated the safety and effectiveness of oral PIH in reducing the body iron burden to near-normal levels in non-transfusion-dependent patients with iron-loading anemias. Study 2 demonstrated the safety and effectiveness of oral PIH in maintaining near-normal body iron stores in transfusion-dependent patients who had previously been well-chelated with chronic subcutaneous or intravenous desferrioxamine. Study 3 demonstrated safety and effectiveness of oral PIH in reducing the body iron burden to near normal levels in iron-loaded transfusion-dependent patients. Studies 1 and 2 were carried out concurrently. Study 3 began after the methods used in the first two studies documented a sufficient level of iron excretion to permit the iron-loaded transfusion patients to keep pace with ongoing transfusional loading and excrete previous accumulations of iron. After an initial 21 day balance study to demonstrate that a selected dose of PIH produced sufficient iron excretion, patients were begun on chronic therapy. PIH or placebo were given on days 4 to 9 and days 13 to 18 in a randomized, double-blind, cross-over design. Study 4 demonstrated the effectiveness in 21 patients of oral deferiprone in inducing sustained decreases in body iron concentrations compatible with the avoidance of complications from iron overload.