Efficacy and safety of bio-chemotherapy with dacarbazine plus interleukin-2 in patients with unresectable malignant melanoma

Aim: This study retrospectively evaluated the toxicity and efficacy of dacarbazine (DTIC) with low-dose subcutaneous interleukin-2 (IL-2) for patients with advanced melanoma. Method: Patients with unresectable malignant melanoma received bio-chemotherapy DTIC (330mg/m², every 3 weeks) and IL-2 18 MIU (million international units) in divided doses by subcutaneous injection three times a week for 4 weeks. Treatment was performed for six cycles or until disease progression or unbearable toxicity. Results: From October 2006 to November 2013, up to 31 patients (17 men; 14 women) were enrolled. Their median age was 48 years (range, 22-81 years). Subtypes of melanoma included 11 (35.4%) acral lentiginous, nodular, 1 (3.2%) superficial spreading, 10 (32.2%) mucosal and 5 (16.1%) others. The response rate was 19.3%, including 3.2% with a complete response, 16.1% with a partial response and 6.3% with stable disease. The median progression-free survival time was 3.5 months (95% CI: 3.0-3.9 months). The median overall survival time was 8.6 months (95% CI: 4.1-10.9 months). The 1-year survival rate was 39% and the 5-year survival rate was 10%. Conclusions: Our data demonstrated that low-dose subcutaneous IL-2 plus DTIC has modest efficacy and may produce long-term survival in small proportion of patients. Furthermore, the treatment is well tolerated by patients.