Iron chelation therapy.

Iron chelation therapy is essential to prevent death from cardiac toxicity in patients with thalassemia major or other severe refractory anemias who need regular blood transfusions. Iron chelating drugs also have potential for clinical use as antiproliferative agents in neoplastic diseases and to reduce free radical-induced tissue damage in rheumatoid arthritis, anthracycline-induced cardiotoxicity, and reperfusion injury. Experimental data and clinical trials also suggest they may have therapeutic value as adjuncts to antimalarial and anti-Pneumocystis carinii therapy and to reduce aluminum toxicity. There is therefore an urgent need for an orally active, inexpensive iron chelating drug, because desferrioxamine, the only currently widely available iron chelator, must be given parenterally and is expensive, making it unavailable for long-term use in many parts of the world. L1 (also known as deferiprone, 1-2 dimethyl-3-hydroxpyrid-4-one, DMHP, and CP20) has emerged as an orally active iron chelator with comparable efficiency to desferrioxamine in both short- and long-term clinical studies. Adverse side-effects, principally agranulocytosis and arthropathy, have raised doubts about its safety, and further trials are now planned to evaluate the incidence of these and other toxicities. Despite numerous studies, no other orally active agent has been shown in clinical trials to be as effective or as safe as L1.