High dose inhalation interleukin-2 therapy for lung metastases in patients with malignant melanoma

The lungs are a frequent site of metastasis in patients with melanoma, and this may cause respiratory problems in the terminal phase of the illness. Inhalation interleukin (IL)-2 therapy to the lung has been piloted and appears to be well tolerated.

Twenty-seven patients were treated with single agent dacarbazine and concurrent high dose inhalation IL-2 36 million IU per day). The patients previously had progressed on chemotherapy, predominately dacarbazine-based regimens. Patients included those with American Joint Committee on Cancer Stage IV melanoma, predominately those with lung metastases, but patients with extrapulmonary metastases also were allowed on the study.

Five of the 27 patients experienced a complete pulmonary remission. Eight patients achieved a partial pulmonary remission, and 5 patients experienced stabilization of their disease. Eight patients developed pulmonary metastases. One patient was not evaluable. Four of the five patients who achieved a complete response and seven of the eight patients who achieved a partial response previously were treated with dacarbazine and progressed. There were no responses in extrapulmonary metastases. Side effects of treatment were minimal. The complete responses all were durable with a follow-up of 12 months, whereas patients with partial responses and stable disease progressed when IL-2 was discontinued.

Inhalation therapy with IL-2 for pulmonary metastases from melanoma appears to be safe. The current preliminary study suggests efficacy although concurrent chemotherapy was given, thus confounding results to some extent. Therefore, these results need to be reproduced without concomitant chemotherapy. In addition, a strategy comprised of therapy with IL-2 inhalation until disease progression may prolong responses.