Thymosin α1 in melanoma: from the clinical trial setting to the daily practice and beyond.

Thymosin α1 (Tα1) is an immunomodulatory peptide released by the thymus gland in mammals. It was first described in 1977 as a potential agent for the treatment of immune deficiencies and cancer. Among solid tumors, a number of clinical trials have investigated the activity of Tα1 in melanoma. In particular, a large randomized phase II trial that evaluated the safety and efficacy of combining Tα1 with dacarbazine and interferon alpha in metastatic melanoma patients provided the rationale for further clinical applications. The main findings emerging from clinical trials and that support the therapeutic use of Tα1 in human melanoma are summarized and discussed.