Intra‐lesional interleukin‐2 for the treatment of in‐transit melanoma

Abstract

To investigate the role of intra-lesional interleukin-2 (IL-2) injection for treatment of in-transit melanoma metastases. Consecutive patients with in-transit metastases were treated with intra-lesional IL-2 injections. Two independent observers evaluated response to treatment using the Response Evaluation Criteria in Solid Tumors (RECIST) criteria. A blinded pathologist confirmed clinical response with post-treatment biopsies. Thirty-nine patients were included. Patients received biweekly IL-2 injections. At each treatment session, a mean of 2.08 ml (5 µ/ml) of IL-2 were distributed amongst a mean of 12 (range 1-57) in-transit lesions. Patients were followed for an average of 30.4 months (range 2.2-66.6 months). The overall patient response rate was 82%. A complete response was obtained in 20 patients (51%), a partial response in 12 (31%), and no response in seven (18%). Of the 629 in-transit metastases, 479 (76%) completely resolved. Complete responders had a significant in transit-free (P = 0.0005) and an overall (P = 0.012) survival advantage compared with partial responders. The treatment of in-transit metastatic melanoma with intra-lesional IL-2 resulted in a 76% percent clearance of lesions. Complete response is associated with superior in transit-free and overall survival when compared with partial response.