Plasma and buffy coat concentration of 8-methoxypsoralen in patients treated with extracorporeal photopheresis.

Recently, a new therapy involving an extracorporal activation of orally administered 8-methoxypsoralen (8-MOP), photosensitizing furocoumarin, is established for the treatment of different skin diseases, extracorporeal photopheresis (ECP). The pharmacokinetic profile of 8-MOP has been pursued as part of a clinical study which should assess the efficacy of ECP in patients with progressive systemic sclerosis and cutaneous T-cell lymphoma. The enormous intra-individual variations proofed for plasma as well as buffy coat concentration are unfavourable for oral 8-MOP therapy. Therefore, the introduction of liquid 8-MOP formulation that allows the direct administration of the drug in to the treatment bag of the ECP device is challenging.