Immune monitoring of phase II trial of hu14.18-IL2 for patients with metastatic melanoma.

e19047 Background: Phase I testing of the hu14.18-IL2 immunocytokine (IC) in patients (pts) with melanoma showed immune activation, reversible toxicities, and a maximal tolerated dose (MTD) of 7.5 mg/m2/day. Methods: In this phase II study, 14 metastatic melanoma pts were scheduled to receive hu14.18-IL2 at 6 mg/m2/day as 4-hour intravenous infusions on days 1, 2 and 3 of each 28 day cycle. Pts with stable disease (SD) or regression following cycle 2 could receive 2 additional treatment cycles. The primary objective was to evaluate anti-tumor activity and response duration. Secondary objectives evaluated adverse events and immunologic activation. Results: All pts received 2 cycles of treatment. One pt had a partial response (PR) [1 PR of 14 pts = response rate of 7.1%; confidence interval 0.2%-33.9%] and 4 pts had SD and received cycles 3 and 4. The PR and SD responses lasted 3-4 months. All toxicities were reversible. Analysis of serum IC for all pts showed a mean value of 1.42 ug/ml on C1D1 and 1.38 ug/...