Phase II study of the anti-ganglioside GD3 mouse/human chimeric antibody KW2871 combined with high dose interferon-a2b in patients with metastatic melanoma.

Abstract

8547 Background: Immunotherapy has demonstrated notable effects in metastatic melanoma (MM) with durable responses achieved by high-dose IL-2 and IFNα2b, leading to approval of these therapies for treatment of melanoma. However, complete responses occur in only a minority of patients. KW2871 is a chimeric monoclonal antibody (mAb) targeting the GD3 ganglioside with demonstrated antitumor activity and enhancement of antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). IFNα2b has potent immunoregulatory, anti-proliferative, differentiation-inducing, pro-apoptotic, and anti-angiogenic properties against a variety of malignancies including melanoma. Combining high dose IFNα2b (HDI) + KW2871 was hypothesized to have synergistic anti-tumor activity due to (1) the ability of HDI to enhance KW2871 induced ADCC in vitro (Liu, Cancer Immun 2002); (2) improved mAb targeting due to increased GD3 expression and induced inflammatory cytokines (TNF-α, IL-4 and IFN-γ) (Hoon, Cancer Res, 1991); (3) increased tumor-infiltrating immune cells (Kirkwood, Cancer 2002; Moschos, J Clin Oncol 2006). Methods: This is an open label, dose-escalation, phase II study of KW2871 plus HDI in patients with measurable MM. Primary objectives are progression-free survival (PFS) and safety. Secondary objectives include assessment for tumor response by RECIST, ADCC, CDC, pharmacokinetics, human antichimeric antibodies (HACA), tumor-infiltrating immune cells, biomarkers and OS. Patients with measurable disease by RECIST, stable brain metastases, and performance status ECOG 0 or 1 are eligible. Patients with severe comorbidities or autoimmune disease or prior exposure to anti-GD3 antibodies are excluded. Sequential enrollment to cohorts of KW2871 at 5, 10 , 20 mg/m2 IV every 2 week in combination with HDI 20 MU/m2 IV once daily x 5 Days for 4 weeks, then 10 MU/m2 SC three times weekly until disease progression. Results: To date, Cohort 1 (5 mg/m2 KW2871) and Cohort 2 (10 mg/m2 KW2871) have been completed safely. Cohort 3 (20 mg/m2 KW2871) has enrolled of 18 of 27 planned patients. Conclusions: Will be presented at study completion.