Temozolomide followed by combined immunotherapy with GM-CSF, low-dose IL2 and IFNα in patients with metastatic melanoma

The purpose of this study is to determine the toxicity and efficacy of temozolomide (TMZ) p.o. followed by subcutaneous (s.c.) low-dose interleukin-2 (IL2), granulocyte–monocyte colony stimulating factor (GM-CSF) and interferon-α 2b (IFNα) in patients with metastatic melanoma. A total of 74 evaluable patients received, in four separate cohorts, escalating doses of TMZ (150–250 mg m−2) for 5 days followed by s.c. IL2 (4 MIU m−2), GM-CSF (2.5 μg kg−1) and IFNα (5 MIU flat) for 12 days. A second identical treatment was scheduled on day 22 and cycles were repeated in stable or responding patients following evaluation. Data were analysed after a median follow-up of 20 months (12–30 months). The overall objective response rate was 31% (23 out of 74; confidence limits 20.8–42.9%) with 5% CR. Responses occurred in all disease sites including the central nervous system (CNS). Of the 36 patients with responding or stable disease, none developed CNS metastasis as the first or concurrent site of progressive disease. Median survival was 252 days (8.3 months), 1 year survival 41%. Thrombocytopenia was the primary toxicity of TMZ and was dose- and patient-dependent. Lymphocytopenia (grade 3–4 CTC) occurred in 48.5% (34 out of 70) fully monitored patients following TMZ and was present after immunotherapy in two patients. The main toxicity of combined immunotherapy was the flu-like syndrome (grade 3) and transient liver function disturbances (grade 2 in 20, grade 3 in 15 patients). TMZ p.o. followed by s.c. combined immunotherapy demonstrates efficacy in patients with stage IV melanoma and is associated with toxicity that is manageable on an outpatient basis.