A safe and effective treatment for in-transit melanoma

The authors evaluated the efficacy and safety of intra-lesion IL-2 for in-transit cutaneous melanoma.

Approximately 10% of patients with locally advanced melanoma develop in-transit cutaneous metastases (melanoma deposits within the lymphatic vessels more than 2cm from the site of the primary melanoma). Eradication of in-transit disease is important as these lesions cause morbidity due to ulceration, bleeding, infection, and pain. Surgery for in-transit disease is a temporary measure, with new lesions often arising promptly, adjacent to the surgical site. Similar to surgery, radiation therapy only works in the direct area treated. To date, the most widely successful therapy for control of in-transit disease has been regional chemotherapy, but this is associated with toxic side-effects. An effective therapy with limited toxic side effects is required.

Aldesleukin (Proleukin) is a drug form of human recombinant IL-2 (causes development and maturation of T-cells, cells of the immune response) used as an immunotherapeutic agent (affecting the immune system). This study evaluated the safety and effectiveness of aldesleukin in in-transit melanoma.

This review analyzed 6 studies on the use of aldesleukin. Each individual study was relatively small, with patient numbers ranging from 7 to 48. After pooling the studies, 140 patients were evaluated with a total number of 2,182 lesions. Intra-lesion IL-2 was administered (injected directly to the lesion).

In 5 of the 6 studies, response rates by lesion were reported, with complete response (the disappearance of all signs of cancer for a given lesion) in 41-96% of lesions. Pooling the studies revealed an overall complete response rate of 78%.

In 4 of the 6 studies, response rates by patient were reported, with complete responses (the complete disappearance of all signs of cancer for a given patient) from 0-69%. Pooling the studies revealed an overall complete response rate of 50%.

The most common side effect was pain and swelling at the injection sites, but this discomfort was mild, short-lived and responded well to oral analgesics (painkillers). Fever and flu-like symptoms occurred in 25-85% of patients. Mild nausea and vomiting was reported in 40% of patients in 1 study.

A standard dosing regimen for the therapy has not yet been established.

The authors concluded that intra-lesion IL-2 (aldesleukin) is a highly effective treatment for in-transit melanoma metastases.