Ethionine: a new antileukaemic drug?

In our hands, benzene proved to be a valuable drug for the treatment of chronic leukaemia. When correctly administered it did not provoke the harmful side effects reported by several authors in accord with the first description of von Koranyi in 1912. In many cases benzene induced complete remission persisting for over 18 months. This compound was found to be active even in patients who had not responded to busulphan, although the contrary was also observed for certain subjects. In accordance with previous investigations carried out in the rabbit, concomitant administration of cysteine-HCl blocked the leucopenic effect of benzene in 5 of 6 cases whereas ethionine, an antimetabolite of methionine and/or cysteine, appeared to enhance its therapeutic action. It is worthy of note that in at least one case ethionine administered alone led to complete clinical and haematological remission of the leukaemic state.