Phase II Study of KW2871 Combined With High Dose Interferon-α2b in Patients With Metastatic Melanoma

Eligible patients were sequentially enrolled into dose-escalating cohorts to receive KW2871 intravenously (IV) once every 2 weeks starting on Day 3 of Week 1 at the following doses: 5 mg/m\^2 in Cohort 1, 10 mg/m\^2 in Cohort 2, and 20 mg/m\^2 in Cohort 3. HDI was administered concurrently at a dose of 20 million units (MU)/m\^2 IV once daily (QD) for 5 consecutive days per week for 4 weeks (induction phase), followed by 10 MU/m\^2 administered subcutaneously (SC) 3 times per week (maintenance phase). Patients received KW2871 and HDI combination therapy until disease progression requiring treatment intervention that would have interfered with the interpretation of the study results. Initially, 3 patients were enrolled within a cohort and evaluated for dose-limiting toxicity (DLT) and regimen-limiting toxicity (RLT) for the first 8 weeks of study treatment. If 1 of 3 patients experienced an RLT, the cohort was expanded to 6 patients. Escalation to the next higher dose cohort proceeded if the RLT rate was \<33% (0/3 or 1/6 patients) in a given cohort. The combination treatment was considered safe if ≤ 20% patients experienced RLT. DLT was defined as any adverse event (AE) that required reduction of the HDI dose or discontinuation of KW2871. RLT was defined as an HDI-related DLT that required more than 2 dose reductions of HDI during the induction phase or the first 4 weeks of the maintenance phase, or any KW2871- or regimen-related DLT.