A multicenter phase II clinical trial using dacarbazine and continuous infusion interleukin-2 for metastatic melanoma. Clinical data and immunomonitoring.

BACKGROUND

Treatment of patients with metastatic melanoma with either dacarbazine or recombinant interleukin-2 (rIL-2) resulted in a response rate of approximately 15%. This study investigates the possible synergism of this chemoimmunotherapy combination.

METHODS

Fifty-seven patients with metastatic malignant melanoma received 135 treatment cycles. Treatment consisted of dacarbazine (Days 1-5) at 250 mg/m2 by a 30-minute slow infusion, and interleukin-2 by constant intravenous infusion (Days 21-25 and 28-32) at 18 x 10(6) IU/m2/24 hours. After this treatment cycle, a 1-week rest was scheduled, and in the absence of undue toxicity or tumor progression, patients received a second cycle as described. Maximum treatment consisted of two induction and four maintenance cycles. In a subgroup of patients, immunoparameters were analyzed to identify prognostic factors. Standard supportive care was given.

RESULTS

Common toxicities included fever, hypotension, nausea/vomiting, anemia, leukopenia, thrombocytopenia, an increase in serum lactic dehydrogenase levels and diarrhea. The objective response rate was 15.8% (one complete response and eight partial responses). In 14 patients, the disease stabilized. For patients who had an objective response, median response duration was 13.9 months (6.3-39.0+), and median survival was 19.0 months (6.3-39.0+); overall survival was 9.3 months (0.8-39.0+). Immunomonitoring did not reveal any relevant prognostic factors for overall response.

CONCLUSIONS

Sequential treatment with dacarbazine and rIL-2 is feasible and produces long-lasting responses in a minority of patients.