aDepartments of Dermatology bSurgery, Division of Surgical Oncology, University of California Davis, School of Medicine cDepartment of Veteran Affairs Northern California Health Care System, Sacramento, California, USA.
There are limited treatment options for metastatic melanoma, which is almost universally fatal. We report the successful treatment of 64 of 64 cutaneous and subcutaneous melanoma metastases in three patients using high-dose (22 million units per 1.2 ml) intralesional interleukin 2 (IL-2) in combination with topical imiquimod and a retinoid cream. Before intralesional therapy, all patients had been treated surgically and were no longer considered surgical candidates. Rebiopsy of 15 of the treatment sites and long-term follow-up (10, 12, and 27 months) showed regression of all treated tumors. Six months after discontinuation of therapy, one patient developed multiple new cutaneous metastases, but these were also responsive to treatment with intralesional therapy. The other two patients did not experience recurrence of their cutaneous melanoma. However, one of the two patients developed lymph node and brain metastases 18 months after initiation of intralesional therapy, but is still alive, now at 27 months. The concentration of IL-2 used for the intralesional therapy was much higher than in previously reported cases, which may explain the excellent responses that were observed. These results support intralesional high-dose IL-2 as a very effective therapy for controlling cutaneous metastatic melanoma. Additional studies are needed to determine whether this therapy is associated with a survival benefit.