Utilization of HPLC-Elisa to Assess Serum Levels of Thymosin α¹Following Subcutaneous Administration to Human Subjects

Thymosin α1 (Tα1) is a 28 aa peptide which is prepared synthetically for clinical use in settings where an immune modulating peptide is predicted to have efficacy. With the increase in clinical studies utilizing Tα1 as a single agent or in combination with other therapeutic agents the need to accurately assess the pharmacokinetics of serum levels of the authentic Tα1 in serum has become clear. Utilizing radioimmunoassays, previous studies have demonstrated elevated levels of thymosin like material in serum for 3–6 hours following administration. This study reports the development of an extraction-analysis procedure which combines HPLC specificity with ELISA sensitivity to measure the levels of authentic Tα. following subcutaneous administration. The precision, specificity and sensitivity data for the procedure is presented as well as data confirming the ability of the procedure to assess levels in human subjects following subcutaneous administration.