Darinaparsin is a covalent organometallic compound, comprising dimethylated arsenic coupled to glutathione. This work involved supporting a clinical trial to assess Darinaparsin as a treatment for patients suffering with peripheral T cell lymphoma, a disease currently with limited treatment options.

PK and PD for total arsenic in plasma and urine was measured using ICPMS, but this approach does not provide information regarding the major circulating and excreted forms.

This poster briefly describes the total Arsenic methods and resulting PK data and then describes the LC-ICP and high-resolution mass spectrometry methods used to characterise the circulating forms. LC-ICP chromatograms and mass spectra are presented for the major identified forms, together with the outcome of the clinical trial.