Thymosin fraction V and intensive combination chemotherapy. Prolonging the survival of patients with small-cell lung cancer.

Patients with small-cell bronchogenic carcinoma who received intensive remission-induction chemotherapy randomly received either thymosin fraction V, 60 mg/sq m or 20 mg/sq m twice weekly, or no thymosin treatment during the initial six weeks of chemotherapy. Chemotherapy was then continued for two years. Thymosin administration did not increase the complete response rate. Patients receiving thymosin, 60 mg/sq m, had significantly prolonged survival times relative to the other treatment groups. This benefit was due to prolonged relapse-free survival in complete responders to treatment. The mechanism by which thymosin increased survival duration is unclear but may relate to restoration of immune deficits due to disease or treatment.