Randomized trial of treatment with cisplatin and interleukin-2 either alone or in combination with interferon-α-2a in patients with metastatic melanoma

BACKGROUND The objective of the current study was to evaluate the response rate, survival, and toxicity of treatment with cisplatin and high dose intravenous continuous infusion interleukin-2 (IL-2) with or without interferon-α-2a (IFN) in patients with metastatic melanoma. METHODS One hundred and seventeen patients with metastatic melanoma randomly were assigned to receive cisplatin, 100 mg/m2, followed after a 3-day rest period by IL-2, 18 × 106 IU/m2, on Days 3-6 and Days 17-21 (Arm 1) or cisplatin and IL-2 using an identical schedule plus subcutaneous IFN, 9 × 106 U, 3 times a week during IL-2 administration (Arm 2). In the absence of disease progression or undue toxicity, the cycle could be repeated on Day 29. Patients who responded after two cycles eventually could receive a third cycle. One hundred and one patients were evaluable for toxicity and efficacy. RESULTS On treatment Arm 1, 3 patients (6%) achieved a complete response (CR) and 5 patients (10%) achieved a partial response (PR) with a median response duration of 3.8 months for the CRs and 8.7 months for the PRs. On treatment Arm 2, 2 patients (3%) achieved a CR (durations of 5.9 and 33.1 months, respectively) and 11 patients (21%) a PR with a median response duration of 8.3 months. The median durations of overall survival were 10.4 months (range, 1.1-39.7+ months) and 10.9 months (range, 0.5-38.1+ months) for treatment Arms 1 and 2, respectively. The toxicity profile was consistent with the known side effects of this IL-2 intravenous regimen combined with cisplatin chemotherapy and IFN. Toxicity was more pronounced in treatment Arm 2 compared with treatment Arm 1. There were 2 and 4 patients, respectively, in treatment Arms 1 and 2 who died within 28 days after completion of treatment. CONCLUSIONS The observed overall response rates of 16% and 25% in treatment Arms 1 and 2, respectively, is lower than that expected with biochemotherapy; despite the fact that the objective of the trial was not to show any difference between the 2 treatment arms, our results indicate that the addition of IFN, at the dose and schedule used in this trial, fails to improve the activity of a cisplatin/IL-2 regimen significantly in patients with metastatic melanoma. Although response rates were relatively low, the median overall survival was nearly 1 year in both groups. Cancer 1999;85:1060–6. © 1999 American Cancer Society.