Recombinant human erythropoietin (r-HuEpo) has been used for the treatment of renal
anemia. With the loss of its patent protection, there has been an upsurge of more affordable
biosimilar agents, increasing patient access to treatment for these conditions. The
complexity of the manufacturing process for these recombinant proteins, however, can result
in altered properties that may significantly affect patient safety. As it is not known whether
various r-HuEpo products can be safely interchanged, we studied 30 patients with chronic …

To the Editor: We have read with great interest the paper by Praditpornsilpa et al. 1 and the
related comment by Wish2 about induction of neutralizing antibodies by biosimilar epoetin
products in Thailand. As far as we know, the only Argentine-manufactured epoetin marketed
in Thailand is Hemax (Bio Sidus SA, Buenos Aires, Argentina), which is probably the
Argentine product mentioned in Praditpornsilpa's report, together with products of other
origins. The induction of such antibodies seems to be a class effect of erythropoiesis …